A strengthening mechanism for sol-gel derived nano-porous silica flms was studied. The silica flms were preparedwith the dip method from two-step catalyzed silica sols and treated in a mixed atmosphere of ammonia and water vaporafterwards. Properties of the flms were analyzed by using atomic force microscopy (AFM), Fourier-transform infraredspectroscopy (FTIR), ellipsometry and an abrasion test, respectively. The experimental results have shown that the twostepcatalysis strengthens the flms and the scratch resistance of the silica flms is further improved after treatment in themixed gas. The increase in strength is attributed to the cross-linking of silica particles by randomly branched or/andentangled linear chains in the sols, more Si-O-Si bonds formed by the mixed gas treatment and structural changes inthe silica flms.

new method to strengthen nano porous broadband anti-reflectance (AR) silica films is described. Silicasols were made from TEOS with a base/acid two-step catalytic process. Properties of silica films deposited witha dip-coat method are characterized with AFM, SEM, spectrophotometer and abrasion test. Experimental resultsshow that the average reflectance ofa glass coated with the nano porous silica films is less than 1% in the visibleregion; and that the two-step catalysis obviously strengthens the films. Finally, the strengthening mechanism ofthe films is discussed.

Hydrophobic organic-inorganic silica hybrid films were prepared by means of a two-step acid-catalyzed methodand sol-gel process using surfactant as template. Methyltriethoxysilane(MTES) and tetraethoxysilane(TEOS) wereco-hydrolyzed in different molar ration and were used as precursors. Addition MTES in TEOS precursors produces adecrease of Si-OH and Si-O- surface content. The infrared spectra of the films thus obtained indicated that they becomehydrophobic with the introduction of the methyl groups. Contact angle instrument was also used to supplement the result.Contact angle values for hydrophobic hybrid films are greater than120 degree. The refractive indices and thickness ofhydrophobic hybrid films are about 1.22-1.24 and about 270-300nm The Optical transmittance spectra and mechanicalintensity measurement results showed that the films have good optical and mechanical properties.

gel materials has received much significant attention recently as it can be used as highly promising cathodic materials for Li-ionbatteries. A novel kind of V2O5 aerogel materials, ambient dried V2O5 aerogel films were reported in this paper. The films were deposited by thedip-coating method and dipped into acetone and cyclohexane by turn to exchange the solvent in the films. Atomic force microscopy (AFM), X-raydiffraction topography (XRD), ellipsometry, and electrochemical measurements were employed to characterize the aerogel films. The porosity ofthe aerogel films is 56%, 16% higher than that of the xerogel films when dried at 120℃. The aerogel films have the higher capacity, as well asbetter reversibility than those of the xerogel films. The improvement of the capacity can be ascribed to the increase of porosity as well as the porediameters after the solvent exchange.

The influence of lithium intercalation on the optical absorption of vanadium pentoxide films is reported in this paper. Thin films wereprepared by thermal evaporation followed by annealing in air. Lithium was inserted electrochemically so that LixV2O5 (0≤x≤0.54) wasobtained. The pristine and lithium inserted films were characterized by X-ray diffraction (XRD), optical spectroscopy, and ellipsometry. Theoptical absorption coefficient was calculated from measured normal transmittance and reflectance spectra. XRD analysis has shown that theas-grown V2O5 films were amorphous, becoming microcrystal after annealing at 350℃. The optical absorption spectra of all the samplesexhibited two distinct regions of behavior: at high-energy where (ahm)1/2 varied linearly with the photonic energy hm, and a low-energy tail.The blue shift of the optical absorption edge is attributed to the Fermi level going into the conduction band after lithium insertion, and therelation between the change of the optical gap and the inserted electron concentration is interpreted in terms of a Burstein-Moss shift. Theresults confirm that the anodic electrochromism of V2O5 thin films is due to the blue shift of the absorption edge, and the near-infraredcathodic electrochromism arises from absorption of small polarons in V205.