Ni Xingyuan

Benzene adsorption properties of silica aerogel-fiber composites

Silica aerogel-fiber composites were prepared via a heat pressing process. Nonwoven fibers were distributed inside the silica aerogels as a composite to act as a supporting skeleton which increased the mechanical strength. The morphology, pore structure, benzene adsorption capacities of the silica aerogels and the composites were characterized. The results show that the silica aerogel-fiber composites have more excellent benzene adsorption capacities compared with the traditional absorbent materials. The saturated benzene-adsorption percentage of the composites has a direct relation with the silica aerogels weight per unit area and the saturated benzene-adsorption percentage of silica aerogels. The experimental results are in good agreement with those calculated by a special formula. The composite process has no influence on the porous structure of the silica aerogels.

Nanostructure control of carbon aerogels and the application in lithium ion cells

Carbon aerogels are derived via a sol-gel process with resorcinol and formodehyde and subsequent pyrolysis of the precursor (RF) aerogels. Due to their high surface area, electrically conducting network and chemical inertness, carbon aerogels can be considered ideal electrodes in rechargeable batteries. In this paper the optimization of the preparation and structure controlling of carbon aerogels are studied. The influence of preparation conditions on the structural properties of carbon aerogels are investigated by scanning electron microscopy, nitrogen adsorption and X-ray diffraction measurements. Carbon electrodes are prepared using carbon aerogels powders and binder, with the carbon aerogel electrode as the anode and with lithium metal foil as the cathode, cells are made. Electrochemical measurements of the lithium intercalation properties for carbon aerogels are performed under high-purity argon in a glove box. The model cells show that the capacity for the first cycle and the rechargeable capacity are all very high, but the ratio of the rechargeable capacity to the total capacity (first cycle) is about 0.3 to 0.4.

Mechanical reinforcement of silica aerogel insulation with ceramic fibers

Silica aerogels doped with ceramic fibers were prepared successfully via sol-gel process with polyethoxydisiloxanes (E-40) as the silicon source. Surface modification was used to realize ambient pressure drying. The morphology, pore structure, mechanical properties and thermal conductivity of the silica aerogels doped with ceramic fibers were investigated. The results show that the ceramic fibers were evenly distributed inside the silica aerogels to increase the mechanical property. The mechanical strength of the silica aerogels increases from 1.6 times 104 pa to 9.6 times 104 pa with the doping of 10% ceramic fibers, while the thermal conductivity is 0.029 w/mmiddotK at room temperature in air. The hydrophobic properties of the doped aerogels are improved a lot by surface modification.

Low dielectric constant and hydrophobic nanoporous silica films

A novel route to prepare low-dielectric constant mesoporous SiO2 films is reported in this paper. Silicate sols are prepared with the precursor TEOS and template CTAB catalyzed by hydrochloric acid. The films are prepared by dip-coating process. FTIIR, XRD and AFM are used to characterize the films. The dielectric constants are measured by impedance analysis apparatus. The films with dielectric constants smaller than 2.2 can be acquired by adjusting the concentration of CTAB and aging time.