02512nas a2200241 4500008004100000022001400041245010100055210006900156260007700225300001400302490000700316520163400323653002101957653001301978653001301991653001302004100002502017700002402042700002602066700002102092700002502113856013202138 2007 eng d a0947-653900aExhaustive analysis of frontal copolymerization of functionalized monovinyl and divinyl monomers0 aExhaustive analysis of frontal copolymerization of functionalize aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcAPR a5862-58720 v133 a

A series of copolymers of 2-hydroxyethyl methacrylate (HEMA)/ glycidyl methacrylate (GMA) and ethylene dimethacrylate (EGDM) were synthesized by frontal polymerization (FP). This study was conducted to investigate the effect of crosslink density, type and concentration of initiator, the use of a complex initiator system, porogen, and diluent on the most relevant parameters of FP, such as sustainability of the front, temperature profile, front velocity, and yield. The products were also characterized for intruded pore volume, pore-size distribution, epoxy-functionality number, and surface morphology. Higher crosslink densities (CLDs) and initiator concentration produced higher front velocities, whereas no trend in front temperature was noted. A complex initiation system was effective in stabilizing and increasing the polymerization yield. Relative to suspension polymerization (SP), FP products synthesized without a solvent were microporous, whereas micro-to-macroporous products were obtained in the presence of a solvent (for HEMA-EGDM polymers). We also present, explain, and discuss the exotic patterns observed under a microscope. We observed two basic types of spatial patterns, namely, planar and nonplanar patterns. The type of planar pattern observed under scanning electron microscopy (SEM) has a spatial impulse that appears as a loop followed by regular periodic motion in the radial and axial directions. This behavior gives rise to a repeating pattern that is a few microns thick. Also, nonplanar patterns, namely, layered concentric rings and winding staircase patterns, were observed under SEM.

10acopolymerization10apatterns10aPolymers10aporosity1 aPujari, Narahari, S.1 aInamdar, Satish, R.1 aAmbekar, Jalindar, D.1 aKulkarni, B., D.1 aPonrathnam, Surendra uhttps://library.ncl.res.in/content/exhaustive-analysis-frontal-copolymerization-functionalized-monovinyl-and-divinyl-monomers-003073nas a2200289 4500008004100000022001400041245010500055210006900160260007300229300001000302490000700312520198800319653002502307653002302332653003502355653002602390653002102416653003202437100001802469700003102487700002502518700002402543700002902567700003002596700002502626856013202651 2012 eng d a1381-117700aEnzyme immobilization on epoxy supports in reverse micellar media: prevention of enzyme denaturation0 aEnzyme immobilization on epoxy supports in reverse micellar medi aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN a54-620 v743 a

Immobilization of enzymes such as alpha-chymotrypsin (EC 3.4.21.1), yeast alcohol dehydrogenase (YADH) from Saccharomyces cerevisiae (EC 1.1.1.1) and glucose dehydrogenase (GDH) from Gluconobacter cerinus (EC 1.1.1.119) has been carried out. Copolymers of allyl glycidyl ether (AGE) crosslinked with 25% ethylene glycol dimethacrylate (EGDM) (25 mg, dry wt) were contacted with the enzymes solubilized in reverse micellar media (0.5-5 mg/mL)(overall) of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) salt in isooctane, and cetyl trimethylammonium bromide (CTAB) in chloroform-isooctane (50:50, v/v). Although the enzymes are readily denatured (>90%) after adsorption on the copolymer in aqueous buffers, no such adsorption-induced denaturation takes place in reverse micelles. alpha-Chymotrypsin is remarkably stable in AOT reverse micelles when 0.025 M citrate buffer of pH 9.0 containing 2 mM CaCl2 is used in the water pools instead of Tris-HCl buffer of pH 8.5. It was possible to achieve enzyme concentration of 5 mg/mL in 0.3 M AOT at molar ratio of water to surfactant, (W-0), 30 and to obtain alpha-chymotrypsin loading of 20 mg/g of copolymer. The recovered enzyme solution can be reused with a fresh batch of polymer after supplementing the depleted solution. The immobilized enzyme exhibits excellent stability in aqueous buffers at room temperature and can be recycled several times. YADH is stable in both AOT and CTAB reverse micelles while GDH is stable only in CTAB reverse micelles containing 0.05 M Tris-HCI buffer of pH 8.5. Interestingly, the combination of YADH (2.5 mg/g) and GDH (0.5 mg/g) co-immobilized on the copolymer using CTAB-chloroform-isooctane system can be used for regeneration and recycle of NADPH at least 50 times as exemplified by complete reduction of a prochiral ketoester, ethyl 4-phenyl-2,4-dioxobutyrate (10 mM) to ethyl (R)-2-hydroxy-4-phenylbutyrate (HPB ester) using NADPH (0.2 mM). (C) 2011 Elsevier B.V. All rights reserved.

10aallyl glycidyl ether10aalpha-Chymotrypsin10aethylene glycol dimethacrylate10aGlucose dehydrogenase10aReverse micelles10aYeast alcohol dehydrogenase1 aThudi, Lahari1 aJasti, Lakshmi, Swarnalath1 aSwarnalatha, Yalangi1 aFadnavis, Nitin, W.1 aMulani, Khudbudin, Baban1 aDeokar, Sarika, Babasaheb1 aPonrathnam, Surendra uhttps://library.ncl.res.in/content/enzyme-immobilization-epoxy-supports-reverse-micellar-media-prevention-enzyme-denaturation-001876nas a2200397 4500008004100000245007700041210006900118260000800187520046300195100002900658700002900687700003000716700001900746700004300765700003000808700002400838700002000862700002700882700002900909700003100938700001900969700003200988700003101020700002901051700002501080700003001105700002801135700003101163700002401194700003001218700003401248700003101282700003301313700002501346856010701371 2012 eng d00aEthyl oligo-silicates with strong acid heterogeneous polymeric catalysts0 aEthyl oligosilicates with strong acid heterogeneous polymeric ca cMAY3 a

The present invention provides a process for the synthesis of ethyl silicate with varying silica concentration, by hydrolysing ethyl silicate in varying water concentration in the presence of sulfonated catalysts having a styrene-divinyl benzene backbone. The present invention further relates to the preparation of beaded crosslinked polymers containing sulfonic acid moieties having an interconnected pore structure and surface area up to 400 m2 /g.

1 aBevara, Madhusudana, Rao1 aBhongale, Sunil, Sitaram1 aBhosle, Sonali, Madhavrao1 aChavan, Nayaku1 aChelanattukizhakkemadath, Raman, Rajan1 aDeokar, Sarika, Babasaheb1 aDhoble, Deepa, Arun1 aDwivedi, Mayank1 aGhorpade, Ravindra, V.1 aHarikrishna, Reghunathan1 aDhanasekharan, Janakiraman1 aJohn, Aruldoss1 aLocanindi, Hari, Sarvothama1 aMomin, Mohasin, Shamshuddi1 aMulani, Khudbudin, Baban1 aMule, Smita, Atmaram1 aNalawade, Archana, Chetan1 aPunitharasu, Vellimalai1 aQureshi, Mohammed, Shadbar1 aKumar, Tayal, Rajiv1 aShaikh, Wasif, Abdul Late1 aSontakke, Kalpana, Vishwanath1 aReddy, Krishna, Mohan Srin1 aSriperambudur, Rajesh, Kumar1 aPonrathnam, Surendra uhttps://library.ncl.res.in/content/ethyl-oligo-silicates-strong-acid-heterogeneous-polymeric-catalysts