Du R.-K.,North University of China |
Du R.-K.,Research Center for Engineering Technology of Polymeric Composites of Shanxi Province |
Liu Q.,North University of China |
Gao B.-J.,North University of China
Guocheng Gongcheng Xuebao/The Chinese Journal of Process Engineering | Year: 2010
The grafting particulate CMPSt/Si02 on which chloromethylated polystyrene was grafted on the surface of silica gel was used as a starting material, and the quaterisation and quaternary phosphine reactions were carried out using triethylamine, tributylamine and triphenyl phosphine as the reagents, resulting in two kinds of composite particles, QN-PSt/Si02 and QP-PSt/Si02. They are water-insoluble materials with high performance. Antimicrobial property of the two composite particles was mainly studied using Escherichia coli as a disease-leading bacterium and with the method of counting live bacterium plate. The relationship between their chemical structure and antibacterial property was examined. Their antibacterial mechanism was explored by measuring extracellular DNA and RNA. The experimental results show that two composiles possess high antibacterial activity, especially QP-PSt/SiO2, its antimicrobial rate can reach 100%. The density of antibacterial groups on the surface and chemical structure of antibacterial groups are the main factors affecting on the antibacterial property of the composite particles. The composite particles with high quaternary degree have stronger antibacterial ability. The antibacterial activity of QP-PSt/SiO2 with phosphine salt-type is much stronger than QN-PSt/SiO2 with quaternary ammonium salt-type. QN-PSt/SiO2 repared with tri-n-butylamine has stronger antibacterial ability than that prepared with triethylamine. The antimicrobial mechanism of QN-PSt/SiO2 and QP-PSt/SiO2 is based on a sterilizing bacterium process.
Zhou X.,North University of China |
Zhao G.,Research Center for Engineering Technology of Polymeric Composites of Shanxi Province |
Niu H.,Research Center for Engineering Technology of Polymeric Composites of Shanxi Province |
Liu Y.,Research Center for Engineering Technology of Polymeric Composites of Shanxi Province
Journal of Materials Science: Materials in Electronics | Year: 2011
Electrically conductive rubber (ECR) was prepared through conventional rubber mixing techniques on a two-roll mill, which the conductive filler was polymer-coated Cu nano-disk and conductive carbon black (CCB). The effect of Cu nanoparticles content on the mechanical and electrical resistivity properties of ECR was further investigated. The obtained results of six different compositions for ECR with 0, 5, 10, 15, 20 and 25 per hundred of rubber (phr) of Cu nanoparticles loading were compared. It was found that ECR has lower volume resistivity and high tensile strength, compared with rubber containing commercial Cu particles. These results suggest that when the Cu particles are nano-disk and surface modified, the mechanical and stability properties of the rubber can be synchronously improved. © 2011 Springer Science+Business Media, LLC.
Li J.,North University of China |
Chen X.,Research Center for Engineering Technology of Polymeric Composites of ShanXi Province |
Han Y.,North University of China
Applied Mechanics and Materials | Year: 2013
This paper introduces the omnidirectional vibration sensor based on MEMS three accelerometer, which is used to solve the problem that the tradition vibration sensor cannot acquire multidimensional vibration signal effectively, on the background of underground distributed passive localization.It has MEMS accelerometer as the core detection unit, including three dimensional vibration detection unit, signal conditioning unit and power supply unit. It adopts the spherical shape,which consists of Aluminum shell, Potting material of Epoxy resin and Multilayer circuit board. By means of finite element analysis and Field test, it shows that this sensor can effectively get omnidirectional vibration signal vector information, and the engineering application value is great. © (2013) Trans Tech Publications, Switzerland.
Du R.,North University of China |
Du R.,Research Center for Engineering Technology of Polymeric Composites of Shanxi Province |
Gao B.,North University of China |
Li Y.,North University of China
Applied Surface Science | Year: 2013
In the presence of acid-acceptor Na2CO3, the nucleophilic substitution between chloromethylated polysulfone (CMPSF) and polyethylene glycol monomethylether (PEGME) was conducted. Polyethylene glycol (PEG) was coupling-grafted onto the side chains of polysulfone (PSF) so that the graft copolymer PSF-g-PEG was prepared and the hydrophilic modification of polysulfone membrane material was realized. The chemical structure of PSF-g-PEG was characterized by FTIR and 1H NMR. The influence of the main factors on the coupling graft reaction was investigated. The water static contact angle of PSF-g-PEG membrane was determined and its property of resisting protein pollution was examined by using bovine serum albumin (BSA) as a model protein. The experimental results show that the coupling graft reaction between CMPSF and PEGME can proceed successfully, and the reaction of chloromethyl groups of CMPSF with the hydroxyl end groups of PEGME is a typical SN1 nucleophilic substitution reaction. The polarity of the solvents and the reaction temperature greatly influence the reaction. The suitable solvent is dimethyl acetamide with stronger polarity and 70 C is a suitable reaction temperature. After reaction of 36 h, the grafting degree of PEG can reach 48 g/100 g and the product yield is about 73.6%. The contact angle of PSF-g-PEG membrane declines rapidly with the increase of PEG grafting degree, displaying the obvious enhancement of the hydrophilicity. The adsorption capacity of BSA on PSF-g-PEG membrane decreases remarkably with the increase of PEG grafting degree, showing excellent antifouling ability of PSF-g-PEG membrane for proteins. © 2013 Elsevier B.V. All rights reserved.