Catalogue en ligne Bibliothèque Ecole Nationale Polytechnique d'Alger

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11294-11300

Titre :	Mechanochemical preparation of 8 - hydroxyquinoline / hydroxyapatite hybrid nanocrystals and their photofunctional interfaces
Type de document :	texte imprimé
Auteurs :	Motohiro Tagaya, Auteur ; Satoshi Motozuka, Auteur ; Takaomi Kobayashi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11294-11300
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nanocrystal Hydroxyapatite Preparation
Résumé :	Hybrid nanoaystals of 8-hydroxyquinoline (8Hq) molecules and hydroxyapatite nanocrystals (HAp) were successfully prepared by a mechanochemical solid-state reaction. The hybrid nanocrystals exhibit a significant thermal stability and efficient photoluminescence peak at 500 nm, which were attributed to metal―ligand charge transfer at the interface between the oxygen atoms of 8Hq and the calcium ions of HAp, and the interfacial photofunctions were inechanochemically controlled. The interfacial bonding structures were also supported by a DV-Xa molecular orbital calculation.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299457

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11284-11293

Titre :	Fluid phase equilibria correlation for carbon dioxide +1 - heptanol system with cubic equations of state
Type de document :	texte imprimé
Auteurs :	Catinca Secuianu, Auteur ; Junwei Qian, Auteur ; Romain Privat, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11284-11293
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Thermodynamic properties Equations of state Carbon dioxide Correlation analysis Correlation Phase equilibrium
Résumé :	The purpose of this paper is to compare three thermodynamic models to correlate the phase behavior of the highly polar system: carbon dioxide +I-heptanol. These three models rely either on the Peng-Robinson (PR) or on the Soave― Redlich―Kwong (SRK) equations of state and are all coupled with classical van der Waals one-fluid mixing rules. For the two first models, noted SRK/2PCMR and PR/2PCMR, where 2PCMR means two-parameter conventional mixing rule, a single set of temperature-independent binary parameters (kij and lij) was considered. The third model is the well-established PPR78 model also based on the PR equation of state (1978 version). In such a model, lij = 0 but the second binary interaction parameter (kij) is temperature-dependent and predicted by a group-contribution method. All available literature data in a wide range of pressures and temperatures and the global phase equilibrium diagram of the system were calculated with the three aforementioned models. Although the models used are simple, they are able to represent reasonably well the complex phase behavior of the system studied in this work.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299456

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11279-11283

Titre :	Conversion of fluorine - containing ozone - depleting and greenhouse gases to valuable polymers in a nonthermal plasma
Type de document :	texte imprimé
Auteurs :	Eric M. Kennedy, Auteur ; Sazal K. Kundu, Auteur ; John C. Mackie, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11279-11283
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Non thermal plasma Greenhouse gas
Résumé :	A dielectric barrier discharge (DBD) nonthermal plasma was used to convert a range of fluorocarbons into useful polymeric products. Reactions were conducted at atmospheric pressure, in an argon bath gas and where methane was added as reactant. The bulk gas temperature was less than 150 °C and yielded polymers from a number of methane/fluorocarbon mixtures, including fluorocarbons such as halons, chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), and perfluorocarbons (PFCs). The results of gel permeation chromatography (GPC) reveal that a potentially valuable polymer is synthesized, with a number average molecular weight of between 60 000 and 130 000 g mol―1 and a polydispersity index (PDI) of between 1.2 and 2.9, depending on the fluorochemical converted.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299455

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11274-11278

Titre :	Helium Recovery by a Cu-BTC Metal–Organic-Framework Membrane
Type de document :	texte imprimé
Auteurs :	Fa Cao, Auteur ; Chunjuan Zhang, Auteur ; Yuanlong Xiao, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11274-11278
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Gas separation membranes
Résumé :	Highly diverse structures and pore sizes make metal–organic frameworks (MOFs) good candidates for the fabrication of gas separation membranes. The synthesis of continuous MOF membranes still remains a challenge. In this work, an integrated Cu-BTC membrane was successfully prepared on the novel potassium hexatitanate support for the first time by in situ solvothermal growth. This kind of support was found to be more suitable for the growth of Cu2+-containing MOF membranes than other traditional supports, such as a porous alumina support. The permeation results of Cu-BTC membranes obtained in this work show moderate separation selectivities of helium over other small gas molecules, including CO2, N2, and CH4. Compared to other MOF membranes, the Cu-BTC membrane exhibits higher ideal selectivity for helium under the condition of similar helium permeance, while it has higher helium permeance with similar ideal selectivity.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301445p

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11266-11273

Titre :	Phosphorus adsorbent derived from concrete sludge (PAdeCS) and its phosphorus recovery performance
Type de document :	texte imprimé
Auteurs :	Atsushi Iizuka, Auteur ; Takeshi Sasaki, Auteur ; Teruhisa Hongo, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11266-11273
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Adsorbents phosphorus
Résumé :	Solid adsorbents for phosphorus recovery (PAdeCS) were prepared from real concrete sludge sampled from an industrial site that produces concrete poles and piles. The concrete sludge was diluted with water at dilution ratios from 1 to 15 to prevent hardening of the cement components. The diluted concrete sludge was then filtered, dried, and used as a solid adsorbent. Two drying methods were examined: natural drying under atmospheric conditions and forced drying in an oven at 105 °C. The phosphorus recovery performances of prepared adsorbents were examined using a potassium dihydrogen phosphate (KH2PO4) solution containing 100 mg-P/L (close to the effluent produced by the sewage sludge dewatering process) as a synthetic for wastewater. All the prepared adsorbents were able to recover phosphorus. Using the forced drying treatment during adsorbent preparation greatly improved the rate of phosphorus recovery from solution. The adsorbent prepared with dilution ratio 10 and forced drying exhibited the highest phosphorus recovery performance. The final phosphorus concentration in solution was 0.83 mg/L, 4 h after addition of the optimized adsorbent, which is extremely promising for application in inexpensive phosphorus recovery processes.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301225g

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11261-11265

Titre :	Molecular - ion - imprinted chitosan hydrogels for the selective adsorption of silver (I) in aqueous solution
Type de document :	texte imprimé
Auteurs :	X. Song, Auteur ; C. Li, Auteur ; R. Xu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11261-11265
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Aqueous solution Adsorption
Résumé :	Chitosan hydrogels were prepared and imprinted by Ag1 with different mass ratios. Compared with the native chitosan hydrogel sample, the optimally imprinted sample (Agim75) presents a significantly enhanced Ag1 adsorption capacity as well as a high selectivity. This is attributed to the specific cavities formed by the template Ag1 ions in the polymer matrix. The effect of the adsorption conditions and desorption process were also studied.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299452

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11254-11260

Titre :	Development of an electrochemical acidification cell for the recovery of CO2 and H2 from seawater II. : Evaluation of the cell by natural seawater
Type de document :	texte imprimé
Auteurs :	Heather D. Willauer, Auteur ; Felice DiMascio, Auteur ; Dennis R. Hardy, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11254-11260
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Seawater Carbon dioxide Acidification
Résumé :	A novel electrochemical acidification process has been developed in a successful feasibility attempt to extract large quantities of CO2 in the form of bicarbonate and carbonate from seawater for potential use as a source of carbon for hydrocarbon production at sea. This indirect approach acidifies seawater by the electrolytic production of acid. Lowering seawater pH was found to be proportional to the applied current to the cell Spontaneous degassing and recovery of CO2 below pH 4.5 was reduced from 92% in synthetic seawater to 30% in natural seawater. The effects of increased operational time, flow rate, current, and natural seawater's complex equilibrium buffer on process performance and CO2 recovery have been shown to be essential for further improvements in future cell design, efficiency, and scale-up.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299451

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11245–11253

Titre :	CFD simulation of gas – liquid – liquid three - phase flow in an annular centrifugal contactor
Type de document :	texte imprimé
Auteurs :	Shaowei Li, Auteur ; Wuhua Duan, Auteur ; Jing Chen, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11245–11253
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Gas liquid
Résumé :	A computational fluid dynamics (CFD) simulation of gas–liquid–liquid three-phase flow was carried out on an annular centrifugal contactor. An Euler–Euler, volume-of-fluid, multiphase-flow model was used for the three-phase flow simulation. The three-phase flow behaviors in the open and sealed inlet operation modes were investigated under various operating conditions. The location and morphology of the aqueous/organic interface were discussed in detail in light of the simulated pressure distribution. An interesting bistability phenomenon was observed in the simulation. The throughput of the annular centrifugal contactor was obtained from the simulation under various phase ratios and compared with experimental results. Excellent agreement was obtained, supporting the validity of the simulation method.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300821t

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11236-11244

Titre :	CO2 Solubility in a mixture absorption system of 2 - Amino - 2 - methyl - 1 - propanol with glycol
Type de document :	texte imprimé
Auteurs :	C. Zheng, Auteur ; J. Tan, Auteur ; Y. J. Wang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11236-11244
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Solubility Carbon dioxide
Résumé :	A mixture system of sterically hindered amine 2-amioo-2-methyl-1-propanol (AMP) with glycol was developed as the working system to reduce energy consumption. The solubility of CO2 in the mixture solutions of AMP―diethylene glycol (DEG) and AMP―triethylene glycol (TEG) was determined by a fast measurement method. The results show that the physical absorption can be enhanced using TEG or DEG as a solvent The heat of absorption of the CO2―AMP―glycol system ranges from 50 kJ/(mol CO2) to 62 kj/(mol CO2) as the loading of CO2 (mol CO2/mol AMP) ranges from 0.2 to 0.8, which is much lower than that between monoethanolamine (MEA) and CO2. The absorption performance of the mixture system is sensitive both to temperature and pressure, which is different from the process with MEA as an absorbent. A reaction assumption of AMP with CO2 in DEG or TEG was suggested and a model for predicting the solubility of CO, is developed accordingly. The prediction results show that the model can predict the absorption performance well. Comparing the MEA―TEG and AMP-TEG systems, we found that the AMP―TEG system would have much lower energy consumption in the CO2 absorption-regeneration process than the MEA―TEG absorption system.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299449

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11226-11235

Titre :	Adsorptive removal of 2,4 - dichlorophenoxyacetic acid (2,4 - D) from aqueous solutions using MIEX resin
Type de document :	texte imprimé
Auteurs :	Lei Ding, Auteur ; Xian Lu, Auteur ; Huiping Deng, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11226-11235
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Aqueous solution
Résumé :	Batch experiments are carried out to evaluate the adsorption performances of 2,4-D from aqueous solutions by MIEX resin. The initial 2,4-D concentration, adsorption time, adsorbent dosage, inorganic ions, natural organic matter, and initial pH of solution have considerable effect on the removal of 2,4-D, but temperature has less effect. The isotherm experiments show the Redllch―Peterson and Sips models are the most appropriate models to simulate the equilibrium data at 293 K. The kinetic study demonstrates the pseudo-second-order model gives a best fitting to the adsorption of 2,4-D on the resin and the intraparticle diffusion is not the only rate-controlling step. The thermodynamic parameters are calculated. The results show that the adsorption of 2,4-D on the resin is a thermodynamically spontaneous and endothermic process. Accordingly, it can be concluded that MIEX resin can potentially be employed as an adsorbent for removing 2,4-D from raw water.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299448

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11218-11225

Titre :	Caesalpinia bonducella leaf powder as biosorbent for Cu (II) removal from aqueous environment : Kinetics and isotherms
Type de document :	texte imprimé
Auteurs :	Gutha Yuvaraja, Auteur ; Munagapati Venkata Subbaiah, Auteur ; Abburi Krishnaiah, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11218-11225
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Kinetics Powder Plant leaf
Résumé :	The ability of Caesalpinia bonducella leaf powder has been utilized as an inexpensive biosorbent for the removal of Cu(II) from aqueous media. Optimum biosorption conditions were found to be pH 5.0, adsorbent dosage 0.07 g/L, agitation speed 180 rpm, and equilibrium time 120 min. Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, and X-ray diffraction were used to characterize the surface functional groups, structure, compositional analysis, and crystallinity of the biosorbent FT-IR analysis shows the involvement of various functional groups such as hydroxyl, amide, carboxyl, and carbonyl groups in the removal of Cu(II) from aqueous environment. Kinetic data were fitted well to a pseudo-second-order kinetic model compared to pseudo-first-order and intraparticle diffusion kinetic models. The equilibrium data were well fitted by the Langmuir isotherm model by revealing the maximum sorption capacity of 76.92 mg/g.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299447

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11207–11217

Titre :	A Multiple - time - region (MTR) - based fault subspace decomposition and reconstruction modeling strategy for online fault diagnosis
Type de document :	texte imprimé
Auteurs :	Zhao, Chunhui, Auteur ; Youxian Sun, Auteur ; Gao, Furong, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11207–11217
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Fault diagnosis
Résumé :	Time-varying fault characteristics have not yet been addressed by conventional fault-reconstruction-based modeling methods, which could affect fault diagnosis performance. In the present work, the multiple-time-region (MTR) nature, that is, the multiplicity of fault characteristics along with the process evolution, is proposed and efficiently analyzed for fault diagnosis. First, an automatic time-region-division algorithm is developed that can partition the whole fault process into different local regions according to the changes in fault characteristics. Different local fault characteristics are thus analyzed by building different representative fault feature models in multiple time regions. Following the changing relationships between the fault and normal operation statuses, different fault reconstruction actions are finally taken in different time regions. By a proper time-region division, the proposed method can better model the time-varying fault behaviors and capture the different fault-to-normal reconstruction relationships for fault diagnosis. The feasibility and performance of the proposed method are illustrated with the Tennessee Eastman process, revealing enhanced fault understanding and improved fault diagnosis performance.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301096x

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11201–11206

Titre :	Cost - effective production of pure Al13 from AlCl3 by electrolysis
Type de document :	texte imprimé
Auteurs :	Wei-Ming Zhang, Auteur ; Jin-Xia Zhuang, Auteur ; Qing Chen, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11201–11206
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Electrolysis
Résumé :	An integrated electrolysis system was built to synthesize polyaluminum chloride with ultra high-basicity and even pure Al13. The system converts AlCl3 solution from aluminum electrode foil industry waste to Al13 chloride directly with reasonable cost, typically $1.09 per kilogram as Al2(OH)5Cl·2H2O at 25 °C. Electrolyte temperature and current density were investigated to optimize the process. Ferron assay and 27Al NMR results indicated that the purity of Al13 is over 99% in product solutions. Ion chromatogram analysis confirmed that Cl– ions accounted for about 96.5% in all counteranions. Our integrated system is the first instance to obtain pure Al13 polycations directly. Similar high purity products are only available after tedious purification. This effective and economic synthesis procedure has potential for mass production of Al13 for water treatment and catalyst as well as cosmetic industries.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301048k

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11183-11200

Titre :	Globally optimal networks for multipressure distillation of homogeneous azeotropic mixtures
Type de document :	texte imprimé
Auteurs :	Paul G. Ghougassian, Auteur ; Vasilios Manousiouthakis, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11183-11200
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Azeotropic mixture Distillation
Résumé :	In this article, a methodology for the globally optimal synthesis of a network of vapor―liquid equilibrium flash separators that can operate at multiple pressures and separate an azeotropic mixture is presented. The objective function minimized is the total flow entering the network flashes. The proposed synthesis methodology employs the infinite-dimensional state-space (IDEAS) conceptual framework, which is shown to be applicable to the problem under consideration. The resulting infinite linear programming (ILP) IDEAS formulation is shown to have several properties that allow its simplification. The approximate solution of this IDEAS ILP is pursued through the solution of a number of finite-dimensional linear programs (FLPs) of ever increasing size, whose optimum values form a sequence that converges to the ILP's infimum. The proposed optimal design methodology is general in nature and can be used to separate any number of pressure-sensitive azeotropic mixtures, with or without use of an entrainer. The method is demonstrated on a first case study involving the dual-pressure separation of a methyl acetate/methanol binary mixture, which exhibits a minimum-boiling azeotrope, without using an entrainer, and a second case study involving the dual-pressure separation of a ternary mixture of water, methanol, and acetone that also exhibits a minimum-boiling azeotrope for the methanol/acetone binary mixture, again without using an entrainer. The IDEAS-generated globally optimal design is shown to be 31.54% better than an optimized, dual-pressure, traditional, two-column design for the binary mixture (case 1) and 15.15% better for the ternary mixture (case 2).
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299444

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11170-11182

Titre :	Model - based identification and analysis of the energy saving potential in batch chemical processes
Type de document :	texte imprimé
Auteurs :	Andrej Szijjarto, Auteur ; Stavros Papadokonstantakis, Auteur ; Konrad Hungerbühler, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11170-11182
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Batchwise Energy conservation Modeling
Résumé :	Optimization of energy consumption for reducing the relevant costs and environmental impacts is constantly gaining attention in chemical batch production. Existing methodologies focus on heat integration considering scheduling constraints and typically result in trade-offs between capital investment and operational costs. However, in multipurpose batch plants, even the allocation of energy flows and the consistent operation according to production recipes pose a great challenge due to batch-to-batch variability and lack of energy utility consumption meters. This paper utilizes a bottom-up modeling approach for energy utility consumption and proposes a method for model-based identification of the energy saving potential in chemical batch plants. The bottom-up models can accurately track the energy utility consumption at various production levels and are used as "soft sensors" for energy efficiency analysis studies. In this context, a set of energy key performance indicators (EKPIs) is proposed for quantifying efficiency in energy use, and an energy saving potential index (ESPI) based on historical plant performance serves as a shortcut method in the case of missing or inaccurate production recipes. The methodology is applied to an industrial multipurpose batch plant for specialty chemicals, exemplifying the obtained efficiency results and targeting energy saving potential for steam consumption.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299443

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11163-11169

Titre :	Rheological behavior of gypsum, plaster, and hydroxyapatite gel blends
Type de document :	texte imprimé
Auteurs :	Mohamed Raii, Auteur ; Francisco Javier Escudero Sanz, Auteur ; Ange Nzihou, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11163-11169
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hydroxyapatite Plaster
Résumé :	The rheological behavior of water―calcium sulfates and hydroxyapatite―calcium sulfates binary blends was considered in this study. These blends are to be used as permeable reactive barriers for groundwater remediation. The influence of gypsum and plaster on the rheological behavior of Ca-HAGel has been studied. The results show that all blends and formulations exhibit a shear-thinning effect and thixotropic behavior. The viscosity also depends on the level of concentration of the solid and the reactivity of the blends. The hydration of plaster causes cohesion and agglomeration between particles due to electrostatic forces, while the hydration of gypsum leads to dispersion due to repulsive forces between particles. The ζ potential was used in this study to understand the interaction between particles and its effect on the global behavior of the blends. The dissolution in water of sulfate ions containing calcium sulfate leads to a change in the surface charge of the blend. This allowed the dispersion or agglomeration of the mixtures to be predicted.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299442

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11157-11162

Titre :	Stable core shell Co3Fe7 – CoFe2O4 nanoparticles synthesized via flame spray pyrolysis approach
Type de document :	texte imprimé
Auteurs :	Yunfeng Li, Auteur ; Yanjie Hu, Auteur ; Junchao Huo, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11157-11162
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Pyrolysis Flame Nanoparticle
Résumé :	Air stable Co3Fe7―CoFe2O4 nanoparticles have been synthesized via one-step flame spray pyrolysis of a mixture of Fe/Co precursor solution under stronger reducing atmosphere. The as-synthesized nanoparticles with diameters of 20-80 nm showed a typical core shell structure and high stability for being one month in air, whose metallic Co3Fe7 cores were protected against oxidation by a surface shell of about 2―4 nm cobalt iron oxide (CoFe2O4). The ratio of metallic Fe/Co alloy nanoparticles was 7:3. The alloy nanoparticles exhibited enhanced saturation magnetization (126.1 emu/g), compared with flame sprayed iron nanoparticles with the same conditions. The formation process of metallic alloy nanoparticles with core-shell structure was investigated, which included three stages: flame combustion, reducing, and surface oxidation during the flame process. It is reckoned that such a continuous production approach is an effective way to produce the stable Co3Fe7 alloy nanoparticles with high saturation magnetization.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299441

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11147-11156

Titre :	Selective area chemical - deposition process : An innovative and facile route to prepare 147Pm sources for dust monitors
Type de document :	texte imprimé
Auteurs :	Manoj Kumar, Auteur ; Rakesh Shukla, Auteur ; Shyamala S. Gandhi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11147-11156
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Surveillance Dust
Résumé :	The potential utility of selective area chemical-deposition technique in the preparation of 147Pm source for the measurement of particulate emission in air was demonstrated. The process consists of electrodeposition of Ni on a precisely defined surface area of a copper wire followed by deposition of 147Pm activity from an aqueous solution. The influences of various experimental parameters such as pH of the aqueous solution, deposition time and reaction volume were systematically investigated for the optimum deposition of 147Pm. To prevent leaching of 147Pm from the source, we subsequently sheathed the radioactive area with a thin layer of polystyrene. The deposited films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and atomic force microscopy (AFM) analyses. The quality of the prepared sources in compliance with regulatory norms were evaluated to ensure their safety during application and found to be satisfactory.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299440

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11137–11146

Titre :	Internal structure and size matters of polyester nanoparticles encapsulating a bioactive hydrophobic drug for the prevention of drug crystals in aqueous systems
Type de document :	texte imprimé
Auteurs :	Eun Chul Cho, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11137–11146
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nanoparticles Bioactive Hydrophobic
Résumé :	This study presents a way of preventing a highly hydrophobic bioactive drug encapsulated in polycaprolactone (PCL) nanoparticles from forming drug crystals aqueous systems. Thymol trimethoxycinnamate was selected as a hydrophobic bioactive model drug. Four PCL-drug nanoparticles were prepared: their internal structures and sizes were regulated by introducing different types of PCL or by changing polymer compositions during the preparation of the nanoparticles. The formation of drug crystals from the PCL-drug nanoparticles was observed by optical microscopy at two temperatures (25 and 40 °C) and in three aqueous mediums (deionized water or aqueous solutions containing 5 wt % butylene glycol or ethanol). In deionized water, the formation of drug crystals could be prevented if PCL-drug nanoparticles have highly crystalline cores. In aqueous solutions containing butylene glycol or ethanol, both the internal crystalline core and the size of the nanoparticles could be important in preventing the drug crystal formation. The present study provides both scientific and practical information to those who involve the drug delivery system and pharmaceutical sciences where drugs are engineered to increase the therapeutic efficiency through polymeric nanoparticles.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300573q

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11128–11136

Titre :	Intercalation of l - alanyl - glutamine dipeptide into layered double hydroxides : Configuration stabilization in confined interlayer region
Type de document :	texte imprimé
Auteurs :	Yongliao Wang, Auteur ; Pingxiao Wu, Auteur ; Yakun Hou, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11128–11136
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hydroxides
Résumé :	In this paper, an unstable chiral drug l-alanyl-glutamine (l-(Ala-Gln)) was intercalated into layered double hydroxides (LDHs) and a systematic study combining experimental and theoretical investigation was carried out. Structural characterization reveals the microstructure of LDHs and properties of the intercalated l-(Ala-Gln). Solid-state UV–vis spectroscopy is adopted to observe the energy absorption. This result shows that LDHs can block the UV light, and inhibition of configuration conversion works in the LDH host. Circular dichroism (CD) spectra suggest that the intercalated l-(Ala-Gln) can maintain its configuration in the interlayer even when irradiated under UV light. Density functional theory (DFT) computations at the B3PW91/6-31G(d, p) level have been carried out to understand the mechanism of l-(Ala-Gln) racemization. The computed result demonstrates that the thermal energy based on the reaction temperature cannot support l-(Ala-Gln) to give an excited state, but it can be excited under the irradiation of UV light with a wavelength less than 240 nm and undergoes conformational transition. When intercalated in the interlayer of LDHs, l-(Ala-Gln) is involved in strong guest–host interaction with the layers and thus inhibition of configuration conversion is effective in the LDH interlayer.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300406b

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11122-11127

Titre :	Effect of hemicellulose pre - extraction on the properties and bleachability of aspen (Populus tremuloides) chemithermomechanical pulp
Type de document :	texte imprimé
Auteurs :	Wei Liu, Auteur ; Qingxi Hou, Auteur ; Changbin Mao, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11122-11127
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Chemithermomechanical pulp
Résumé :	Pre-extraction of hemicelluloses prior to pulping and conversion of the extracted hemicelluloses to other byproducts will provide additional revenue to the traditional pulp and paper industry. The effect of hemicelluloses pre-extraction with dilute sulfuric acid on the properties and bleachability of aspen (Populus tremuloides) chemithermomechanical pulp (CTMP) was investigated. The acid pre-extraction significantly reduced refining energy consumption to a given freeness. However, at the same freeness, the acid pre-extraction resulted in the reduction of bulk, tensile index, and zero-span breaking length, fewer long fibers and more fines, but an increase of the Scott bond strength. Alkaline peroxide bleaching can compensate the strength loss, but the bleachability of pulps with acid pre-extraction was lower than that of the control.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299437

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11112-11121

Titre :	Selective hydrogenation of cinnamaldehyde over Pt and Pd supported on multiwalled carbon nanotubes in a CO2 - expanded alcoholic medium
Type de document :	texte imprimé
Auteurs :	Bao-Hui Zhao, Auteur ; Jian-Gang Chen, Auteur ; Xuan Liu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11112-11121
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Carbon dioxide Hydrogenation
Résumé :	Pt/MWCNT and Pd/MWCNT nanocatalysts were prepared via a liquid reduction method. The selective hydrogenation of cinnamaldehyde (CAL) was investigated over 5.0 wt.% Pt/MWCNT and 5.0 wt% Pd/MWCNT catalysts in a CO2-enpanded alcoholic medium at different reaction conditions. The hydrogenation selectivities over these two catalyst types were shown to be entirely different. It was found that the Pt/MWCNT catalysts are highly selective for C=O bonds, giving the unsaturated alcohol a selectivity for cinnamyl alcohol (COL) of 97.3% and a conversion rate for cinnamaldehyde of 99.3%. Conversely, the Pd/MWCNT catalyst is highly selective for C=C bonds, producing a saturated aldehyde with a selectivity for hydrocinnamaldehyde (HCAL) of 91.3% and a conversion rate for cinnamaldehyde of 98.6%. The small diameter of the Pt or Pd granules over the multiwalled carbon nanotubes (MWCNTs) leads to a high catalyst activity, and an increase of CO2 pressure results in a better hydrogenation performance for C=O bonds than that for C=C bonds.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299436

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11104-11111

Titre :	Fast degradation and biodegradability improvement of reactive brilliant red X - 3B by the cobalt(II) / bicarbonate / hydrogen peroxide system
Type de document :	texte imprimé
Auteurs :	Zhen Yang, Auteur ; Hong Wang, Auteur ; Min Chen, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11104-11111
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hydrogen peroxide Biodegradability
Résumé :	The cobalt(II)-bicacbonate (HCO3―) complex is a very efficient catalyst for organic dye decolorization with H2O2 as an oxidant, but its mineralization degree is very low. One interesting alternative is the combination of the system with a subsequent biological step. With the aim of employing the Co2+-HCO3― system as a pretreatment method to dye wastewater, a typical azo dye, reactive brilliant red X-3B (X-3B), was selected as the model compound, and the biodegradability enhancement of the dye was investigated. The results showed that X-3B was effectively degraded by the Co2+-HCO3― system under various mild conditions, and the BOD5/COD ratio of the dye solution could markedly increase from 0.046 to higher than 0.46. The effluent treatment by the system was efficiently post-treated in a batch biological reactor with the COD removal around 44% after 8 h aeration, while a little decrease of the COD value of the raw solution was observed.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299435

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11097-11103

Titre :	Green approach for wastewater treatment — degradation and mineralization of aqueous organic pollutants by discharge plasma
Type de document :	texte imprimé
Auteurs :	P. Manoj Kumar Reddy, Auteur ; Ch. Subrahmanyam, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11097-11103
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Plasma Pollutant Mineralization Waste water purification
Résumé :	A dielectric barrier discharge reactor was designed and tested for the degradation of a model aqueous pollutant crystal violet (CV). The specific advantage of the present configuration is the effective utilization of reactive species generated in the discharge plasma. The reactive species formed in the discharge, particularly the OH• radicals, may cause strong oxidizing effects in the degradation of CV. Mineralization of the dye was confirmed by TOC analyzer and infrared gas analyzer. It was observed that both degradation efficiency and TOC removal increased with increasing the input energy; however, the energy yield decreased. The highest energy yield achieved was 86.3 (g/kWh). Formation of hydrogen peroxide was quantified and addition of Fe2+ increased the performance of the reactor. The dye degradation followed first-order kinetics.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299434

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11091-11096

Titre :	Boron Oxide Production Kinetics Using Boric Acid as Raw Material
Type de document :	texte imprimé
Auteurs :	Suna Balci, Auteur ; Naime Asli Sezgi, Auteur ; Esin Eren, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11091-11096
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Raw materials Kinetics Production
Résumé :	Boron oxide with a content of 99.93 wt.% from the dehydration of boric acid was synthesized. Conversion of boric acid to boron oxide was completed within 3 days at low temperature range (T < 130 °C) and approximately 30 min at high temperature range (T > 130 °C) for the isothermal dehydration reaction in the temperature range of 80 and 350 °C. Apparent activation energies were 65 and 28 kJ·mol―1 for low and high temperature ranges, respectively. Thermogravimetric analysis (TGA) results showed that the reactions were nearly completed at around 330 °C, and activation energy for the first temperature region was found to be two-thirds of the isothermal value and the same for the second temperature region. Isothermal data analysis revealed that the apparent reaction order value was around 1.0 at low temperature range and decreased to 0.55 with temperature within the high temperature range.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299433

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11083-11090

Titre :	Controllable synthesis, structure, and catalytic activity of highly dispersed Pd catalyst supported on whisker - modified spherical alumina
Type de document :	texte imprimé
Auteurs :	Yang Li, Auteur ; Junting Feng, Auteur ; Yufei He, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11083-11090
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalyst support Catalyst activity
Résumé :	A new route was introduced to synthesize novel mesoporous spherical alumina supports by in situ growth of alumina whiskers on the surface, and in the pores, of conventional spherical alumina using urea as an OH― donor and a surfactant as a structure-directing agent. BET results indicate that the modified spherical alumina exhibited much higher surface area and more regular mesoporous structure than the unmodified alumina. The whisker-modified spherical aluminas with a flowerlike arrangement of whiskers and higher surface area were then used as support to prepare highly dispersed Pd catalysts. Catalytic performances of the catalysts were studied in the catalytic hydrogenation/oxidation of 2-ethylanthraquinone (EAQ). Compared with a conventional Pd/alumina catalyst, novel Pd/whisker-modined alumina catalysts exhibited much higher Pd dispersion which resulted in more catalytically active sites and therefore significantly higher hydrogenation efficiency. Moreover, shorter diffusion distance reduced the deep hydrogenation of EAQ and consequently achieved higher selectivity and structural stability.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299432

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11072–11082

Titre :	Synthesis gas generation by chemical - looping reforming in a circulating fluidized bed reactor using perovskite LaFeO3 - based oxygen carriers
Type de document :	texte imprimé
Auteurs :	Xiao Ping Dai, Auteur ; Jie Li, Auteur ; Jiang Tao Fan, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11072–11082
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Gas Oxygen carriers
Résumé :	Perovskite-based LaFeO3/Al2O3–Kaolin oxygen carriers, prepared by a wet-mixing–kneading method, have been examined for chemical-looping reforming over a microfixed bed reactor and a circulating fluidized bed reactor. An oxygen carrier containing 60% LaFeO3 over 15Al2O3-25Kaolin exhibits higher reactivity, and can converted methane to syngas with high selectivity. The addition of Al2O3–Kaolin improves the oxygen migration rate from bulk to surface, and increases the amount of the very reactive oxygen species for CO2 formation. The CH4 conversion and CO selectivity rely heavily on reaction temperature and bed height. Increasing the fuel reactor temperature and bed height is beneficial for the reforming application with natural gas as fuel over a bubbling fluidized bed reactor. Preliminary results on the circulating fluidized bed reactor show that the CH4 conversion is about 25%, and CO selectivity is about 70% at an oxygen carrier-fuel molar ratio (1.32) and 900 °C. It is helpful to improve the redesign of the experimental facility and optimization of process parameters in further research. There is still a high potential for further improvement in mechanical strength and attrition resistance of perovskite-based oxygen carrier by optimization of binder and support.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300033e

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012)

Titre :	Kinetic study on stereospecific polymerization of 1,3 - butadiene using a nickel based catalyst system in environmentally friendly solvent
Type de document :	texte imprimé
Auteurs :	Archana Singh, Auteur ; Ankur Chavda, Auteur ; Subrahmanyam Nandula, Auteur
Année de publication :	2012
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalyst Polymerization Kinetics
Résumé :	The present work describes the stereospecific polymerization of 1,3-butadiene catalyzed by a nickel naphthenate/ triethylaluminum/boron trifluoride etherate catalytic system in a noncarcinogenic solvent mixture. The detailed study on the effect of various parameters on the polymerization and product characteristics is reported. The catalyst concentration and reaction temperature did not have any significant effect on microstructure. Moreover, the conversion was observed to be the maximum at a 1.07 boron trifluoride/alkylaluminum molar ratio. The effect of catalyst concentration showed that at lower concentrations, a lower number of active sites leads to higher molecular weight (Mw) while the polydispersity index (PDI) exhibited a reverse trend. The polymerization was first order with respect to monomer as well as catalyst concentration. The overall rate constant was found to be 0.032 s―1 mol―1 for this catalyst system. The activation energy of the polymerization was found to be 14.1 kcal mol―1.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299430

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11059-11065

Titre :	Synthesis of three novel intumescent flame retardants having azomethine linkages and their applications in EVA copolym
Type de document :	texte imprimé
Auteurs :	Yan Liu, Auteur ; Yan Zhang, Auteur ; Zhenhu Cao, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11059-11065
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Flame retardant
Résumé :	Three novel intumescent flame retardants (IFRs), polyphosphate esters (designated as PDP, PEP, and PPP), were synthesized by reacting phenyl dichlorophosphate with three bis-hydroxy azomethine monomers through interfacial polycondensation. The polyphosphate esters were characterized by hydrogen nuclear magnetic resonance (1H NMR), Fourier transform infrared spectroscopy (FTIR), and gel permeation chromatography (GPC). Thermal stability and flammability properties of ethylene vinyl acetate copolymer (EVA)/30%IFRs blends were investigated by thermogravimetric analysis (TGA), limited oxygen index (LOI), and microscale combustion calorimeter (MCC). The EVA/IFRs blends exhibited high thermal stabilities, and char yields at 600 °C were 11―19% in nitrogen. The results from MCC indicated that the addition of PPP to EVA reduced the PHRR by about 33%, while the LOI values increased from 19 to 22. Scanning electron microscope (SEM) observation results indicated that the existence of the tight charred layer on the surface of the residues was responsible for the improvement of the flame retardancy of EVA.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299429

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11054–11058

Titre :	Influence of pH and conductivity on properties of paper made of polyelectrolyte multilayered recycled fibers
Type de document :	texte imprimé
Auteurs :	Hamidreza Rudi, Auteur ; Yahya Hamzeh, Auteur ; Ghanbar Ebrahimi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11054–11058
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Properties paper Polyelectrolyte Fibers
Résumé :	This study focuses on the modification of recycled fiber surface through polyelectrolyte multilayer (PEM) assembly of cationic and anionic starches using the layer-by layer (LbL) technique. The properties of handsheets made of those multilayered fibers under various pH values and salt concentrations of the pulp suspension were evaluated. It was found that ζ-potential variations had a close correlation with consecutive multilayer construction, and conductivity shifts influenced ζ-potential and strength characteristics more than varying the pH did. Mechanical properties of the handsheets, i.e., tensile index and internal bonding (Scott type), showed considerable improvement ranging from 125 to 365% depending on the pH and conductivity of the pulp suspension. Moreover, higher pH values between 7.5 and 10 and low electrolyte content around 0.001 M NaCl (140 μS/cm conductivity) were found to be the best conditions to assemble PEMs on recycled fibers, possibly as a consequence of the increased degree of fiber and polyelectrolyte ionization and more efficient conformation of polyelectrolyte.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301467f

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11045–11053

Titre :	Extraction, recovery, and characterization of hardwood and grass hemicelluloses for integration into biorefining processes
Type de document :	texte imprimé
Auteurs :	Ryan J. Stoklosa, Auteur ; David B. Hodge, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11045–11053
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hemicelluloses Biorefining processes
Résumé :	For this work, four hardwoods (silver birch, sugar maple, a hybrid poplar, and a hybrid aspen) and one cultivar of switchgrass were treated with increasing levels of NaOH. The recovered cell wall biopolymers were characterized based on total extraction, precipitation using ethanol or acidification, xylan content, and molar mass of the recovered precipitates. The extractability of cell wall polymers was clearly shown to be a function of the biomass type with more than 50% of the cell walls of switchgrass solubilized by alkali while only up to 20% of the maple was solubilized under comparable conditions. Precipitation with ethanol resulted in high recovery yields of hemicelluloses from the original biomass for silver birch and switchgrass, and most notably, the birch precipitates contained double the hemicellulose content of the precipitates from other feedstock alkali extracts (80% versus 30–50%). The molar masses of the recovered hemicellulosic polysaccharides were characterized using size exclusion chromatography (SEC) and an assay to quantify polysaccharide reducing ends. SEC analysis showed that the biopolymers exhibited a strong tendency to self-associate during elution and that this aggregation could be eliminated through sonication. The reducing end method showed an increase in the number-average degree of polymerization toward an asymptotic maximum with increasing extraction pH, and this value was significantly increased by bleaching the precipitate to remove interference by nonpolysaccharides.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301260w

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11038-11044

Titre :	Solvent effects on cure in a 2K polyurethane — mechanical and dielectric studies
Type de document :	texte imprimé
Auteurs :	Stephen Monaghan, Auteur ; Richard A. Pethrick, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11038-11044
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Solvent effect
Résumé :	The effect of change in solvent type on the processes involved in film formation of a 2K polyurethane are investigated using dynamic mechanical thermal analysis [DMTA] and dielectric relaxation [DR] measurements. The film formation and cure reactions for a polyol reacting with an isocyanate for solutions in ethyl acetate, tolene, xylene, and n-butyl acetate solutions and their mixtures are reported. Mechnical studies are used to observe the various stages of film formation and cure using a paper substrate. The fluid initially wets the substrate and film formation accompanies solvent evaporation. The rate of these initial processes correlates well with the vapor pressure of the solvent. The rate of cure of the films however is influenced by the polarity of the solvent system. Analysis of the broad band dielectric relaxation data yields conductivity data, which can be modeled to give kinetic data on the cure process. The rate of cure of this 2K system demonstrates sensitivity to the solvent composition used. The rate constant derived from conductivity data parallel those derived previously from FTIR studies. DMTA and DR measurements indicate that as cure proceeds, the glass transition temperature—Tg, increases. Differences are observed in the ambient temperature-cured films, which reflect retained solvent plasticization. of the matrix. Post cure aids release of trapped solvent and the final physical properties are essentially independent of the solvent used in the cure process.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299426

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11031-11037

Titre :	Enhanced flame retardant property of fiber reactive halogen - free organophosphonate
Type de document :	texte imprimé
Auteurs :	Megumi Yoshioka-Tarver, Auteur ; Brian D. Condon, Auteur ; Michael Santiago Cintron, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11031-11037
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Flame retardant
Résumé :	In this paper, we studied the synthesis, characterization, and flammability of the water-soluble, nonhalogenated organophosphorus flame retardant (FR) dimethyl-[1,3,5-(3,5-triacryloylheoahydro)triazinyl]-3-oxopropylphosphonate for application to cotton fabrics by nonpolymeric network. The FR was synthesized in a one-step reaction from dimethyl phosphite and 1,3,5-triacryloylhezahydro-1,3,5-triazine under mild conditions, and its structure was fully characterized by 1H, 13C, and 31P nuclear magnetic resonance (NMR), mass spectrometry (MS), and Fourier transform infrared spectroscopy (FT-IR). The finishing conditions to achieve a covalent bond between the FR and fibers were optimized, and the FR capability of the treated cotton was investigated by limiting oxygen index (LOI), flame test, thermogravimetric analysis (TGA), and micro cone calorimeter (MCC) tests. This study showed that fabrics treated with the FR are effectively flame resistant, and the FR property is enhanced by covalent bonding of the FR to fibers.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299425

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11021-11030

Titre :	Origin of impurities formed in a polyurethane production chain. Part 2 : A route to the formation of colored impurities
Type de document :	texte imprimé
Auteurs :	June Callison, Auteur ; Franziska Betzler, Auteur ; Kimberly de Cuba, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11021-11030
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Color Production Impurity
Résumé :	The quality of methylene diphenyl diisocyanate (MDI) products, which are valuable feedstocks in the industrial manufacture of polyurethanes, can be compromised by the presence of color, presumed to arise from trace impurities. One undesired branch in the synthesis chain originates with phosgenation of diaryl ureas, formed from reactions between aryl isocyanates and polyamine precursors. Subsequent key steps include, (i) breakdown of the primary compounds, substituted chloroformamidine-N-carbonyl chlorides (CCC), to give aryl isocyanide dichlorides, ArNCCl2, (ii) an apparent equilibrium connecting CCC with aryl carbodiimides, and (iii) the thermolysis of ArNCCl2 in the presence of MDI. Color formation is associated directly with the last process; it involves several events, including HCl elimination from reaction of ArNCCl2 and MDI, formation of carbon-centered radicals, and a contribution from oxidation at the methylene bridge.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299424

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11011-11020

Titre :	Ether - functionalized trialkylimidazolium ionic liquids : Synthesis, characterization, and properties
Type de document :	texte imprimé
Auteurs :	Yide Jin, Auteur ; Shaohua Fang, Auteur ; Ming Chai, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11011-11020
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Ionic liquid
Résumé :	A family of new ether-functionalized ILs based on trialkylimidazolium cations with one or two ether groups and TFSA― anion was synthesized and characterized. Their properties including melting point, thermal stability, viscosity, conductivity, and electrochemical windows were determined and compared to those of the trialkylimidazolium ILs without ether group. The relationship between the cations structure and IL physicochemical properties was systematically studied. Most of these ether-functionalized ILs were liquids at room temperature, and the melting points of 21 ILs were lower than ―60 °C. At room temperature, 26 ILs owned the viscosities lower than 100 mPa s, and the viscosities of IM(2o1)12TFSA and IM(2o2)12TFSA were 57.4 and 54.4 mPa s.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299423

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 11005–11010

Titre :	Microwave synthesis of fullerene - doped MgB2
Type de document :	texte imprimé
Auteurs :	C. Plapcianu, Auteur ; A. Agostino, Auteur ; P. Badica, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11005–11010
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Microwave
Résumé :	Unconventional in situ synthesis of MgB2 undoped and doped with fullerene (C60) was performed by using a single-mode microwave (MW) furnace. Structural properties suggested that C substitutes for B in the crystal lattice of MgB2, while the Jc showed typical enhancement at high magnetic fields when C chemical doping occurred. This behavior was similar to published results for another field-activated unconventional method of processing, i.e., spark plasma sintering, and it was opposite to the conventional powder-in-tube method for which chemical substitution was not realized when using addition of C60. Certain morphologically unique features such as the occurrence of needlelike grains were revealed in the MW samples. Our MW samples showed higher relative density (≤83%) than previously reported data. Magnetic relaxation experiments suggested the presence of microscopic flux jumps in the MW samples, while macroscopic flux jumps were not observed.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3005429

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 34 (Août 2012) . - pp. 10983-11004

Titre :	Cement formation — a success story in a black box : High temperature phase formation of portland cement clinker
Type de document :	texte imprimé
Auteurs :	Samira Telschow, Auteur ; Flemming Frandsen, Auteur ; Kirsten Theisen, Auteur
Année de publication :	2012
Article en page(s) :	pp. 10983-11004
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Portland cement
Résumé :	Cement production has been subject to several technological changes, each of which requires detailed knowledge about the high multiplicity of processes, especially the high temperature process involved in the rotary kiln. This article gives an introduction to the topic of cement, including an overview of cement production, selected cement properties, and clinker phase relations. An extended summary of laboratory-scale investigations on dinkerization reactions, the most important reactions in cement production, is provided. Clinker formations by solid state reactions, solid―liquid and liquid―liquid reactions are discussed, as are the influences of particles sizes on clinker phase formation. Furthermore, a mechanism for clinker phase formation in an industrial rotary kiln reactor is outlined.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26299421

Industrial & engineering chemistry research / Paul, Donald R. . Vol. 51 N° 34

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