Study On Components Of Surface Modification Of Titanium Dioxide

Titanium dioxide （TiO₂） is an important inorganic functional material，which hasbeen extensively used in the fields, such as paint, plastic, papermaking, printing ink,chemical fiber and cosmetics, for its distinct properties in physics and chemistry.However, the agglomerating of TiO₂without surface modification in organic solventand the photo catalysis activity limit its application. Accordingly, the TiO₂can beeffectively surface modified to decrease its photo catalysis activity and increase itsdispersion in organic solvent is the key that whether TiO₂can be applied widely. Thereare two types of surface modification methods are inorganic process and organicprocess. The purpose of inorganic modification is mainly to improve its weatherresistance and chalking resistance, but the research on organic modification focuses onimproving the dispersion properties.In this paper, some solvents were firstly used to wash out the surfacemodification coating. Then eluted liquid is characterized by infrared spectrum （IR）,Thermo gravimetric-differential thermal analysis （TG-DTA） and gaschromatography-mass spectrometry （GC-MS） to explore the structure of organiccoating compound used for surface modification. The results show that60of all69samples have been surface modified mainly by polyatomic alcohol （39%） and silanecoupling agent （29%）, others by titanate coupling agent.The effect of surface modification are evaluated by transmission electronmicroscope （TEM） analysis, oil absorption measurement, contact angle demonstratedand sedimentation. The results showed that the samples No.2,7,36and37wereexcellent products because of their excellent stability, wettability, dispersibility andlower oil absorption capacity. What’s more, surface organic modification can improveits dispersion properties to some extent. However, the dispersion properties is good orbad not only depends on organic or inorganic modification, also on particle sizedistribution and granule morphology closely.The research shows that the wetting ability of samples modified by polymer isbad because the k value is too small. The samples modified by silane coupling agentgenerally have lower oil absorption capacity. Whereas, the wetting ability of samples inxylene need to be improved. On the contrary, the samples modified by organic aminehave excellent wetting ability and dispersion stability. Meanwhile, the samples modified by titanate coupling agent tend to agglomerate in linseed oil.