Imprinting of protein over silica nanoparticles via surface graft copolymerization using low monomer concentration

2010 ◽  
Vol 26 (2) ◽  
pp. 760-765 ◽  
Author(s):  
Hongyan He ◽  
Guoqi Fu ◽  
Yan Wang ◽  
Zhihua Chai ◽  
Yizhe Jiang ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Graft Copolymerization ◽  
Monomer Concentration ◽  
Surface Graft

DETERMINATION OF A SUITABLE CONDITION OF GRAFT COPOLYMERIZATION OF VINYLTRIETHOXYSILANE ONTO NR TO FORM NANOMATRIX STRUCTURE

2018 ◽  
Vol 91 (4) ◽  
pp. 767-775 ◽  
Author(s):  
Yuanbing Zhou ◽  
Yoshimasa Yamamoto ◽  
Seiichi Kawahara
Keyword(s):  
Silica Nanoparticles ◽  
Graft Copolymerization ◽  
Monomer Concentration ◽  
Minor Component ◽  
Suitable Condition ◽  
Average Diameter ◽  
Silica Matrix ◽  
Rubber Particles ◽  
Hydrolysis And Condensation ◽  
Nanomatrix Structure

ABSTRACT Graft copolymerization of vinyltriethoxysilane (VTES) onto NR particles in the latex stage is a unique reaction, since it occurs together with hydrolysis and condensation of the triethoxysilane group of VTES to form a colloidal silica linking to the rubber particles. These reactions may contribute to the formation of a silica nanomatrix structure that consists of a dispersoid of rubber particles as the major component and a silica matrix as the minor component. Here, the graft copolymerization of VTES followed by hydrolysis and condensation is investigated to determine a suitable condition to prepare NR with a silica nanomatrix structure. The mechanical properties of the resulting graft copolymer are discussed in relation to the morphology, silica content, and gel content of the rubber. Based on morphological observations, NR particles with an average diameter of approximately 1 μm are well dispersed in a nanomatrix consisting of silica nanoparticles. The thickness of the silica nanomatrix increases as the monomer concentration increases, and a long incubation time generates large silica nanoparticles. The tensile strength and viscoelastic properties are significantly improved by forming the silica nanomatrix structure, with its continuous structure that prevents the NR particles from merging.

Electroless deposition of nickel on fluoropolymers modified by surface graft copolymerization

2002 ◽  
Vol 38 (11) ◽  
pp. 2153-2160 ◽  
Author(s):  
G.H. Yang ◽  
C. Lim ◽  
Y.P. Tan ◽  
Yan Zhang ◽  
E.T. Kang ◽  
...  
Keyword(s):  
Electroless Deposition ◽  
Graft Copolymerization ◽  
Surface Graft

scholarly journals New Grafted Copolymers Carrying Betaine Units Based on Gellan and N-Vinylimidazole as Precursors for Design of Drug Delivery Systems

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5451
Author(s):  
Stefania Racovita ◽  
Nicolae Baranov ◽  
Ana Maria Macsim ◽  
Catalina Lionte ◽  
Corina Cheptea ◽  
...  
Keyword(s):  
Graft Copolymerization ◽  
Polymer Concentration ◽  
Monomer Concentration ◽  
Ammonium Persulfate ◽  
Nitrogen Atmosphere ◽  
Sustained Drug Release ◽  
Reaction Conditions ◽  
Grafted Polymer ◽  
Grafted Copolymer ◽  
Grafting Reaction

New grafted copolymers possessing structural units of 1-vinyl-3-(1-carboxymethyl) imidazolium betaine were obtained by graft copolymerization of N-vinylimidazole onto gellan gum followed by the polymer-analogous reactions on grafted polymer with the highest grafting percentage using sodium chloroacetate as the betainization agent. The grafted copolymers were prepared using ammonium persulfate/N,N,N′,N′ tetramethylethylenediamine in a nitrogen atmosphere. The grafting reaction conditions were optimized by changing one of the following reaction parameters: initiator concentration, monomer concentration, polymer concentration, reaction time or temperature, while the other parameters remained constant. The highest grafting yield was obtained under the following reaction conditions: ci = 0.08 mol/L, cm = 0.8 mol/L, cp = 8 g/L, tr = 4 h and T = 50 °C. The kinetics of the graft copolymerization of N-vinylimidazole onto gellan was discussed and a suitable reaction mechanism was proposed. The evidence of the grafting reaction was confirmed through FTIR spectroscopy, X-ray diffraction, 1H-NMR spectroscopy and scanning electron microscopy. The grafted copolymer with betaine structure was obtained by a nucleophilic substitution reaction where the betainization agent was sodium chloroacetate. Preliminary results prove the ability of the grafted copolymers to bind amphoteric drugs (cefotaxime) and, therefore, the possibility of developing the new sustained drug release systems.

Influence of Reaction Conditions on the Properties of Nano-matrix Structure Formed by Graft-Copolymerization of Acrylonitrile onto Natural Rubber

2013 ◽  
Vol 844 ◽  
pp. 365-368 ◽  
Author(s):  
Kontapond Prukkaewkanjana ◽  
Seiichi Kawahara ◽  
Jitladda Sakdapipanich
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Graft Copolymerization ◽  
Monomer Concentration ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Matrix Structure ◽  
Oil Resistance ◽  
Wide Range ◽  
Initial Monomer

Natural rubber (NR) is one of the most important agriculture products of Thailand, which is an important material with unique and special characteristics used in wide range of applications such as mechanical properties, excellent strength, and elasticity. However, it is inferior in oil resistance due to the presence of hydrogen and carbon in its structure. This inherent drawback of NR has limited its application in industry. In order to expand the use of NR, this research is interested to improve the oil resistance of NR without loss of outstanding properties by grafting NR with acrylonitrile (AN) monomer to form the nano-matrix structure. The influences of the initial monomer concentration and initial initiator concentration were investigated. These effects on structure, mechanical properties and oil resistance properties were studied by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy, tensile machine, and swelling in toluene, respectively. It was found that the tensile strength and oil resistance properties of graft copolymerization of AN onto NR increased with increasing the percentage grafting efficiency of acrylonitrile monomer.

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