The Preparation And Characterization Of The PVA-CS-TiO₂Composite Film

Polyvinyl alcohol (PVA) has many excellent qualities such as with goodfilm-forming property, solvent resistance, and chemical resistance. PVA-CS compositefilm was made by blending Polyvinyl alcohol (PVA) with Chitosan (CS).Analyzing byinfrared absorption spectroscopy (FTIR), X-ray, thermal properties (DSC), Atomic forcemicroscopy (AFM), the results showed that the addition of CS reduced the crystallinityof PVA and the two element had a good compatibility.The tests of the mechanicalproperties, water resistance and the permeability indicated that when PVA: CS is equal to6:4, the composite properties of the film are optimum.By adding nanometer TiO₂into PVA-CS hybrid solution, we synthesized thePVA-CS-TiO₂composite film which has nanometer constructive. By means of X-ray,FTIR, scanning electron microscopy (SEM) analysis, it is showned that nanometer TiO₂particles dispersed in the polymer matrix uniformly, and a good compatibility with thepolymer matrix. Based on the test results of PVA-CS-TiO₂composite film mechanicalproperties, swelling energy absorption and solution separation ability, we concluded thatwhen the content of nanometer TiO₂reaches0.3g,the mechanical properties, swellingenergy absorption and solution separation ability of composite film were the best.Based on the study of the degradation rate of the PVA-CS-TiO₂composite film,wefound that when the illumination is2h, nanometer particle content is0.3g/100ml. thedegradability of composite film reaches23.4%.By the mechanical properties testsultraviolet spectrum analysis and FTIR analysis. The photocatalytic degradationmechanism of the PVA-CS-TiO₂composite film was raised and proved.It is showned thatin photocatalytic degradation process, molecular chain fractured, and the structuralformula of C=O generated.