نتایج جستجو برای: polymeric catalyst

تعداد نتایج: 67474  

2014
Marcos Alexandre Gelesky Carla Weber Scheeren

Rhodium and platinum nanoparticles were supported in polymeric membranes with 10, 20 and 40 μm thickness. The polymeric membranes were prepared combining cellulose acetate and the ionic liquid (IL) 1-n-butyl3-methylimidazolium bis(trifluoromethane sulfonyl)imide (BMI.(NTf) 2 . The presence of metal nanoparticles induced an increase in the polymeric membrane surface areas. The increase of the IL...

2009
Rodolfo Moreno-Fuquen Leidy J. Valencia Alan R. Kennedy Denise Gilmour R. H. De Almeida Santos

The title compound, C(15)H(14)O(2), was obtained by Friedel-Crafts acyl-ation between 2,5-dimethyl-phenol and benzoyl chloride in the presence of aluminium chloride as a catalyst. The dihedral angle between the benzene rings is 61.95 (4)°. In the crystal, O-H⋯O hydrogen bonding and C-H⋯O weak inter-actions lead to polymeric C(6), C(8) and C(11) chains along the a, b and c-axis directions, respe...

2002
D. Joniak M. Polakova

New biodegradable surface active agents were prepared by glycosidation of prehydrolysis lignin with the D-glucose using anhydrous ferric chloride as the catalyst which afforded polymeric alkyl, benzyl and aryl glucofuranoside derivatives of lignin. Moreover, a series of novel lignin-based surface active agents was obtained by subsequent Oxidation of the primary alcohol groups of u-glucose into ...

2015
Heather C Johnson Andrew S Weller

{Rh(xantphos)}-based phosphido dimers form by P-C activation of xantphos (4,5-bis(diphenylphosphino)-9,9-dimethylxanthene) in the presence of amine-boranes. These dimers are active dehydrocoupling catalysts, forming polymeric [H2 BNMeH]n from H3 B⋅NMeH2 and dimeric [H2 BNMe2 ]2 from H3 B⋅NMe2 H at low catalyst loadings (0.1 mol %). Mechanistic investigations support a dimeric active species, su...

2008
I. Gracia J. F. Rodríguez A. de Lucas M. P. Fernández

The objective of the study is the development of a new technique based on supercritical technology for the production of bioabsorbable polymeric microparticles containing pharmaceutical principles, for their use in the controlled release of medicines. For this purpose, the ring-opening copolymerization of D,L-lactide and glycolide in supercritical carbon dioxide, using zinc(II) 2-ethylhexanoate...

Journal: :Chemical communications 2012
Senem Karahan Mehmet Zahmakıran Saim Özkar

A new type of supported rhodium nanoparticles were reproducibly prepared from N(2)H(4)BH(3) reduction of [Rh(μ-Cl)(1,5-cod)](2) without using any solid support and pre-treatment technique. Their characterization shows the formation of well dispersed rhodium(0) nanoparticles within the framework of a polyaminoborane based polymeric support. These new rhodium(0) nanoparticles were found to be the...

2017
Joost Clerx Stijn F. M. van Dongen Kasper Nørgaard Michael A. Trakselis Scott W. Nelson Stephen J. Benkovic Alan E. Rowan Roeland J. M. Nolte

In processive catalysis, a catalyst binds to a substrate and remains bound while performing several consecutive reactions, as exemplified by DNA polymerases. Processivity is essential in Nature, and is often mediated by a clamp-like structure that physically tethers the catalyst to its (polymeric) template. In the case of the bacteriophage T4 replisome, a dedicated clamp protein acts as a proce...

Journal: :The International Journal of Advanced Culture Technology 2015

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1392

a novel acrylic acid-functionalized fe3o4 magnetic nanoparticle with a core-shell structure was developed for utilization as a heterogeneous organosuperacid in chemical transformations. the structural, surface, and magnetic characteristics of the nanosized catalyst were investigated by various techniques such as transmission electron microscopy (tem), thermogravimetric analysis (tga), and ft-ir...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید