Documents disponibles écrits par cet auteur

Controlled size silver nanoparticles synthesis with water - in - oil microemulsion method / Jignasa N. Solanki in Industrial & engineering chemistry research, Vol. 50 N° 22 (Novembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 22 (Novembre 2011) . - pp. 12311–12323 Titre : Controlled size silver nanoparticles synthesis with water - in - oil microemulsion method : a topical review Type de document : texte imprimé Auteurs : Jignasa N. Solanki, Auteur ; Zagabathuni Venkata Panchakshari Murthy, Auteur Année de publication : 2012 Article en page(s) : pp. 12311–12323 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Nanoparticles  Microemulsion Résumé : Synthesis of noble metallic nanoparticles, in general, and silver nanoparticles (SNPs), in particular, currently are of special interest. In the present paper, an overview of the enhanced properties of SNPs and consequential applications of SNPs are discussed. Common synthesis methods and their comparison with the microemulsion technology, particularly advantages of SNPs formation with microemulsion technology, are discussed. A brief overview of the basics of microemulsion technology for nanoparticles formation is also presented. The complete topical review of microemulsion synthesis technique used to date for the generation of SNPs is discussed comprehensively. Control parameters have been explicated for influencing size, size uniformity, and stability aspects of the SNPs reported in the literature, allowing a tailored synthesis for specific application. Recent modifications made on the synthesis of SNPs to obtain monodisperse, high yield and stability are also discussed. Lastly, some future trends and perspectives in these research areas are outlined. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201649x [article] Controlled size silver nanoparticles synthesis with water - in - oil microemulsion method : a topical review [texte imprimé] / Jignasa N. Solanki, Auteur ; Zagabathuni Venkata Panchakshari Murthy, Auteur . - 2012 . - pp. 12311–12323. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 22 (Novembre 2011) . - pp. 12311–12323 Mots-clés : Nanoparticles  Microemulsion Résumé : Synthesis of noble metallic nanoparticles, in general, and silver nanoparticles (SNPs), in particular, currently are of special interest. In the present paper, an overview of the enhanced properties of SNPs and consequential applications of SNPs are discussed. Common synthesis methods and their comparison with the microemulsion technology, particularly advantages of SNPs formation with microemulsion technology, are discussed. A brief overview of the basics of microemulsion technology for nanoparticles formation is also presented. The complete topical review of microemulsion synthesis technique used to date for the generation of SNPs is discussed comprehensively. Control parameters have been explicated for influencing size, size uniformity, and stability aspects of the SNPs reported in the literature, allowing a tailored synthesis for specific application. Recent modifications made on the synthesis of SNPs to obtain monodisperse, high yield and stability are also discussed. Lastly, some future trends and perspectives in these research areas are outlined. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201649x

Enhancing the stability of oil - in - water emulsions emulsified by coconut milk protein with the application of acoustic cavitation / Virangkumar N. Lad in Industrial & engineering chemistry research, Vol. 51 N° 11 (Mars 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4222-4229 Titre : Enhancing the stability of oil - in - water emulsions emulsified by coconut milk protein with the application of acoustic cavitation Type de document : texte imprimé Auteurs : Virangkumar N. Lad, Auteur ; Zagabathuni Venkata Panchakshari Murthy, Auteur Année de publication : 2012 Article en page(s) : pp. 4222-4229 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Acoustic  cavitation  Emulsion  Stability Résumé : Coconut milk protein (CMP) is a naturally derived protein recovered from the kernel of fresh coconut (Cocos nucifera L.) having a high nutrient value. With increasing demand of naturally available efficient emulsifiers and stabilizers for the production of food and health care emulsions with reasonable stability, many emulsifiers are being utilized for the commecial production of many products. Even though the CMP is reported as a poor emulsifier, we prepared very stable emulsions with CMP using sonication. The effects of ultrasound (250 W, 20 kHz and 120 W, 20 kHz) on the stability of sunflower oil in-water emulsions made by CMP are studied. It is found that though the acoustic energy is responsible for further reduction of droplet size for CMP emulsions, energetic cavitations and high pressure shock waves, generated due to the collapsing bubble, are responsible for droplet breakup. The size of the dispersed droplets, in the case of sonication using an ultrasonic horn with all the concentrations of CMP, was smaller than that created using an ultrasonic bath. Emulsions sonicated by the ultrasonic horn were found to be very stable with variation of salt concentration. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25655631 [article] Enhancing the stability of oil - in - water emulsions emulsified by coconut milk protein with the application of acoustic cavitation [texte imprimé] / Virangkumar N. Lad, Auteur ; Zagabathuni Venkata Panchakshari Murthy, Auteur . - 2012 . - pp. 4222-4229. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4222-4229 Mots-clés : Acoustic  cavitation  Emulsion  Stability Résumé : Coconut milk protein (CMP) is a naturally derived protein recovered from the kernel of fresh coconut (Cocos nucifera L.) having a high nutrient value. With increasing demand of naturally available efficient emulsifiers and stabilizers for the production of food and health care emulsions with reasonable stability, many emulsifiers are being utilized for the commecial production of many products. Even though the CMP is reported as a poor emulsifier, we prepared very stable emulsions with CMP using sonication. The effects of ultrasound (250 W, 20 kHz and 120 W, 20 kHz) on the stability of sunflower oil in-water emulsions made by CMP are studied. It is found that though the acoustic energy is responsible for further reduction of droplet size for CMP emulsions, energetic cavitations and high pressure shock waves, generated due to the collapsing bubble, are responsible for droplet breakup. The size of the dispersed droplets, in the case of sonication using an ultrasonic horn with all the concentrations of CMP, was smaller than that created using an ultrasonic bath. Emulsions sonicated by the ultrasonic horn were found to be very stable with variation of salt concentration. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25655631

Investigation of different drug deposition techniques on drug releasing properties of cardiovascular drug coated balloons / Pankaj J. Gandhi in Industrial & engineering chemistry research, Vol. 51 N° 33 (Août 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 33 (Août 2012) . - pp. 10800–10823 Titre : Investigation of different drug deposition techniques on drug releasing properties of cardiovascular drug coated balloons Type de document : texte imprimé Auteurs : Pankaj J. Gandhi, Auteur ; Zagabathuni Venkata Panchakshari Murthy, Auteur Année de publication : 2012 Article en page(s) : pp. 10800–10823 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Techniques  Drug  Releasing  Properties Résumé : The advent of the drug eluting stent (DES) has changed the management of coronary vessel revascularization very effectively. However, a DES imposes risk of long-term adverse clinical events such as inadequate vascular endothelization, inflammatory response, and stent thrombosis. A drug coated balloon offers advantages of deploying antiproliferative drugs at blocked lesions while eliminating the long-term risk associated with drug eluting stents. The major mechanism of drug delivery from this coated balloon involves adsorption of drug particles on inner lumen of coronary artery upon balloon expansion after which drug diffuses to the inner layers due to the concentration gradient. The major challenges in engineering such drug delivery devices are (1) to retain majority amount of drug on balloon during tracking and (2) program faster drug delivery within shorter exposure time. In the current research work, we have adopted different drug coating methods such as dip coating, brush coating, coating with ultrasonic atomization, and coating with air brush spray method to coat nanoparticles of Sirolimus drug encapsulated in phospholipids. For each of the methods, samples were studied for drug loading, coating integrity, and release characteristics of the Sirolimus coated balloon. An arterial path was simulated to measure the amount of drug loss during navigation and tracking. Drug release was measured for each of the coated system in phosphated buffer saline (PBS) solution of pH 7.4 and in Hank’s solution of 7.4 pH at 37 °C at different time intervals. Also, the sample surface was analyzed for coating integrity after coating, after tracking, and after drug release. The resultant surface characteristics were correlated to the stages of balloon coating, tracking, and drug release, respectively. Among the different coating techniques employed, the method that was best in terms of coating durability and release effectiveness was further investigated for the drug release mechanism using available mathematical models. The analyses of drug loading on balloon surfaces and drug release from balloon surfaces were evaluated with the help of different statistical techniques. It is found that release of drug was not purely under influence of diffusion but mechanical abrasion during balloon expansion also played vital role. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3006676 [article] Investigation of different drug deposition techniques on drug releasing properties of cardiovascular drug coated balloons [texte imprimé] / Pankaj J. Gandhi, Auteur ; Zagabathuni Venkata Panchakshari Murthy, Auteur . - 2012 . - pp. 10800–10823. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 33 (Août 2012) . - pp. 10800–10823 Mots-clés : Techniques  Drug  Releasing  Properties Résumé : The advent of the drug eluting stent (DES) has changed the management of coronary vessel revascularization very effectively. However, a DES imposes risk of long-term adverse clinical events such as inadequate vascular endothelization, inflammatory response, and stent thrombosis. A drug coated balloon offers advantages of deploying antiproliferative drugs at blocked lesions while eliminating the long-term risk associated with drug eluting stents. The major mechanism of drug delivery from this coated balloon involves adsorption of drug particles on inner lumen of coronary artery upon balloon expansion after which drug diffuses to the inner layers due to the concentration gradient. The major challenges in engineering such drug delivery devices are (1) to retain majority amount of drug on balloon during tracking and (2) program faster drug delivery within shorter exposure time. In the current research work, we have adopted different drug coating methods such as dip coating, brush coating, coating with ultrasonic atomization, and coating with air brush spray method to coat nanoparticles of Sirolimus drug encapsulated in phospholipids. For each of the methods, samples were studied for drug loading, coating integrity, and release characteristics of the Sirolimus coated balloon. An arterial path was simulated to measure the amount of drug loss during navigation and tracking. Drug release was measured for each of the coated system in phosphated buffer saline (PBS) solution of pH 7.4 and in Hank’s solution of 7.4 pH at 37 °C at different time intervals. Also, the sample surface was analyzed for coating integrity after coating, after tracking, and after drug release. The resultant surface characteristics were correlated to the stages of balloon coating, tracking, and drug release, respectively. Among the different coating techniques employed, the method that was best in terms of coating durability and release effectiveness was further investigated for the drug release mechanism using available mathematical models. The analyses of drug loading on balloon surfaces and drug release from balloon surfaces were evaluated with the help of different statistical techniques. It is found that release of drug was not purely under influence of diffusion but mechanical abrasion during balloon expansion also played vital role. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3006676

Reduction of nitro aromatic compounds over Ag/Al2O3 nanocatalyst prepared in water-in-oil microemulsion / Jignasa N. Solanki in Industrial & engineering chemistry research, Vol. 50 N° 12 (Juin 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7338-7344 Titre : Reduction of nitro aromatic compounds over Ag/Al2O3 nanocatalyst prepared in water-in-oil microemulsion : effects of water-to-surfactant mole ratio and type of reducing agent Type de document : texte imprimé Auteurs : Jignasa N. Solanki, Auteur ; Zagabathuni Venkata Panchakshari Murthy, Auteur Année de publication : 2011 Article en page(s) : pp. 7338-7344 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Surfactant  Microemulsion Résumé : Silver nanoparticles, with controlled sizes, are synthesized by chemical reduction of silver nitrate with sodium borohydride reducing agent by microemulsion method. To obtain small and monodisperse particles, as-synthesized Ag nanoparticles are readily tuned by varying the water-to-surfactant mole ratio, ω (most crucial operating parameter), and the type of reducing agent. Superior nanoparticles are obtained at intermediate ω (ω = 3). When hydrazine hydrate is used as reducing agent, further superior nanoparticles are obtained with a calculated surface area of 9.76 x 108 mm2/g and hence are chosen for further nanocatalyst synthesis by proper deposition of the same on alumina support. The catalyst is analyzed with UV―visible spectroscopy and X-ray diffraction techniques to confirm the presence of metallic silver. The synthesized catalyst can be conveniently recovered from the reaction system, leading to easy monitoring of the catalytic reaction by spectroscopic methods. Accordingly, reduction of model nitro aromatic compounds, viz., 4-nitrophenol and 4-nitroaniline, are studied. Gradual disappearance of the peak corresponding to nitro compounds reveals the degradation of nitro compounds with time. Furthermore, the appearance and increase of new peaks with time reveal the progressive formation of respective products. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239049 [article] Reduction of nitro aromatic compounds over Ag/Al2O3 nanocatalyst prepared in water-in-oil microemulsion : effects of water-to-surfactant mole ratio and type of reducing agent [texte imprimé] / Jignasa N. Solanki, Auteur ; Zagabathuni Venkata Panchakshari Murthy, Auteur . - 2011 . - pp. 7338-7344. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 12 (Juin 2011) . - pp. 7338-7344 Mots-clés : Surfactant  Microemulsion Résumé : Silver nanoparticles, with controlled sizes, are synthesized by chemical reduction of silver nitrate with sodium borohydride reducing agent by microemulsion method. To obtain small and monodisperse particles, as-synthesized Ag nanoparticles are readily tuned by varying the water-to-surfactant mole ratio, ω (most crucial operating parameter), and the type of reducing agent. Superior nanoparticles are obtained at intermediate ω (ω = 3). When hydrazine hydrate is used as reducing agent, further superior nanoparticles are obtained with a calculated surface area of 9.76 x 108 mm2/g and hence are chosen for further nanocatalyst synthesis by proper deposition of the same on alumina support. The catalyst is analyzed with UV―visible spectroscopy and X-ray diffraction techniques to confirm the presence of metallic silver. The synthesized catalyst can be conveniently recovered from the reaction system, leading to easy monitoring of the catalytic reaction by spectroscopic methods. Accordingly, reduction of model nitro aromatic compounds, viz., 4-nitrophenol and 4-nitroaniline, are studied. Gradual disappearance of the peak corresponding to nitro compounds reveals the degradation of nitro compounds with time. Furthermore, the appearance and increase of new peaks with time reveal the progressive formation of respective products. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24239049