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Gao X.,Beijing University of Chemical Technology | Wu D.,State Key Laboratory of Organic Inorganic Composites | Zheng X.,Beijing University of Chemical Technology | Liu Y.,Beijing University of Chemical Technology
Advanced Materials Research | Year: 2013

In this paper, the filling coefficient is defined by the ratio between effective by light area and the total area of the light diffuser when a beam of light strikes it, namely micro lens array structure of configuration density. In order to analyze the relation between the filling coefficient of the microstructure and the optical properties of the diffuser, the filling coefficient is expressed as center-to-center spacing of the microstructure. As the the center-to-center spacing increases, the filling coefficient becomes smaller.and the relation between the filling coefficient of the diffuser microstructure and the optical properties of diffuser have also been simulated by the Light Tools software based on the Monte-Carlo Method. Then the test sample which has the same aspect ratio and filling coefficient with the simulation sample has been obtained by using micro injection casting, Comparing the haze and transmittance of the experimental diffuser with the simulation result, the relation between the filling coefficient of the diffuser microstructure and the optical properties of diffuser have been gotten. © (2013) Trans Tech Publications, Switzerland. Source


Liu Y.,Key Laboratory of Preparation and Processing of Novel Polymer Materials | Zhang L.-Q.,Key Laboratory of Preparation and Processing of Novel Polymer Materials | Zhang L.-Q.,Beijing University of Chemical Technology | Wang W.-C.,Beijing University of Chemical Technology | And 5 more authors.
Journal of Applied Polymer Science | Year: 2012

A novel method for the organic modification of a ceramic thermal conductive filler (α-alumina) with cold plasma was developed for the preparation of elastomer thermal interface materials with high thermal conductivities and low moduli. The α-alumina fillers were first coated with low-molecular-weight polydimethylsiloxane (PDMS) by solution dispersion and then treated in argon plasma for different time. The modified α-alumina fillers were characterized with high-resolution transmission electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The results revealed that a thin PDMS film with several nanometers thick was tightly coated on the surface of the alumina filler after plasma treatment, and this thin film could not be removed by 48 h of Soxhlet extraction with n-hexane at 120°C. Plasma modification of the alumina could dramatically weaken the strength of the filler-filler networks and, thus, remarkably reduce the modulus of the alumina-filled silicone rubber composites but did not affect the thermal conductivity of the composites. © 2011 Wiley Periodicals, Inc. Source


Xiang Z.,State Key Laboratory of Organic Inorganic Composites | Peng X.,Beijing University of Chemical Technology | Cheng X.,State Key Laboratory of Organic Inorganic Composites | Li X.,Beijing University of Chemical Technology | Cao D.,State Key Laboratory of Organic Inorganic Composites
Journal of Physical Chemistry C | Year: 2011

Effectively separating CO 2 from the natural gas, which is one of alternative "friendly" fuels, is a very important issue. A hybrid material CNT@Cu 3(BTC) 2 has been prepared to separate CO 2 from the CO 2/CH 4 mixture. For comparison of separation efficiency, a series of representative metal-organic frameworks (MOF-177, UMCM-1, ZIF-8, MIL-53 (Al), and Cu 3(BTC) 2) have also been synthesized by the solvothermal method. Adsorption isotherms of CO 2 and CH 4 pure gases are measured by Hiden Isochema Intelligent Gravimetric Analyzer (IGA-003). The dual-site Langmuir-Freundlich (DSLF)-based ideal adsorption solution theory (IAST) is used to predict adsorption of each component in the CO 2/CH 4 mixture. The IAST-predicted results show that the hybrid material CNT@Cu 3(BTC) 2 exhibits the greatest selectivity among the six materials, and its selectivity keeps in the range of 5.5 to 7.0 for equimolar CO 2/CH 4 mixture at 1 < p < 20 bar, which is higher than activated carbons. Moreover, the selectivity of CNT@Cu 3(BTC) 2 for the CO 2/CH 4 mixture keeps almost no change with the composition of CH 4, which is one of the excellent properties as a promising separation material. In short, this hybrid material CNT@Cu 3(BTC) 2 shows great potential in separation and purification of CO 2 from various CO 2/CH 4 mixtures by adsorptive processes in important industrial systems. © 2011 American Chemical Society. Source


Fu Y.,State Key Laboratory of Organic Inorganic Composites | Fu Y.,Beijing University of Chemical Technology | Liu L.,Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials | Liu L.,Beijing University of Chemical Technology | And 4 more authors.
ACS Applied Materials and Interfaces | Year: 2014

Using tetraethyl orthosilicate as a main raw material, silica nanofibers (SiNFs) were prepared through the combination of a sol-gel process and an electrospinning technique followed by pyrolysis. Surface modified electrospun SiNFs developed by self-polymerization of polydopamine on the surface (SiNFs-PDA) served as templates for the electroless plating of silver nanoparticles (Ag NPs), using glucose as a reducing agent. The electrical resistivity of silver coated SiNPs-PDA (SiNFs-PDA/Ag) was measured by the four-point probe method and was found to be as low as 0.02 mΩ·cm at room temperature. The morphology of SiNFs-PDA/Ag before and after the blending with silicon rubber indicated a strong interaction between the silver layer and the SiNFs-PDA. The electrical and mechanical properties of the silicon rubber filled with SiNFs-PDA/Ag were studied to demonstrate the conductive performance application of SiNFs-PDA/Ag. © 2014 American Chemical Society. Source


Chen Y.,State Key Laboratory of Chemical Resource Engineering | Liu L.,State Key Laboratory of Chemical Resource Engineering | Liu L.,Key Laboratory of Carbon Fiber and Functional Polymers | Yang Q.,State Key Laboratory of Organic Inorganic Composites | And 5 more authors.
Langmuir | Year: 2013

In this work, nonequilibrium molecular dynamics simulations were performed to investigate the dispersion and spatial distribution of spherical nanoparticles (NPs) in polymer matrix under oscillatory shear flow. We systematically analyzed the influences of four important factors that consist of NP-polymer interfacial strength, volume fraction of NPs, shear conditions, and polymer chain length. The simulation results showed that the oscillatory shear can greatly improve the dispersion of NPs, especially for the polymer nanocomposites (PNCs) with high NP-polymer interfacial strength. Under specific shear conditions, the NPs can exhibit three different spatial distribution states with increasing the NP-polymer interfacial strength. Interestingly, at high interfacial strength, we observed that the NPs can be distributed on several layers in the polymer matrix, forming the PNCs with sandwich-like structures. Such well-ordered nanocomposites can exhibit a higher tensile strength than those with the NPs dispersed randomly. It may be expected that the information derived in present study provides a useful foundation for guiding the design and preparation of high-performance PNCs. © 2013 American Chemical Society. Source

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