Study On The Preparation And Application Of TiO₂/Opal Composite

Filler is the second most important material for paper products.In the papermaking process,the fillers that are widely used are kaolin,talc,calcium carbonate and titanium dioxide.However,due to high price and shortage of resources,titanium dioxide is only used in high-quality paper.Amorphous silica is produced by controlled acidification of sodium silicate solutions.The classic industrial method of preparing silica powder usually uses sulfuric acid,however,in order to reduce the costs and protect the environment,choosing more effective methods will have considerable commercial significance.In this paper,the rutile TiO₂is deposited on the surface of opal by air flow stirring to prepare TiO₂/opal composites.The composite prepared is similar to the rutile TiO₂ in optical properties,which can be applied in papermaking industry.At the same time,the TiO₂/SiO₂ composite was prepared by adding rutile TiO₂ in the process of extracting SiO₂ from opal by carbonization method.Both composite materials can effectively improve the performance of paper products.In addition,we use carbon dioxide instead of organic or inorganic acids to prepare silica powder,which is environmentally friendly and economical.Firstly,the airflow stirring method was used to deposit rutile TiO₂ on the surface of the opal to prepare TiO₂/opal composites with different rutile TiO₂loadings.FESEM,XRD,UV-Vis,and FT-IR test results show that rutile TiO₂ is deposited on the surface of opal,when the addition amount of rutile TiO₂ in the TiO₂/opal composite is 20%（w/w）relative to the mass of the opal,the deposition effect of the composite is the best.The UV absorption performance of the composite is closest to that of titanium dioxide.The whiteness test results show that the whiteness of the composite is improved relative to opal.Secondly,in the process of preparing silicon dioxide by carbonization,a certain amount of rutile TiO₂ is added to prepare a series of TiO₂/SiO₂composites.The XRD and FT-IR test results show that amorphous silica can be extracted by carbonization method.FESEM test results show that when the addition amount of rutile TiO₂ in the TiO₂/SiO₂ composite is 15%,the dispersion of the composite is the best.The whiteness test of the prepared SiO₂powder shows that its whiteness value is 98%.Finally,the prepared TiO₂/opal and TiO₂/SiO₂ composites are used as fillers in papermaking,the optical properties and mechanical properties of the obtained paper are tested to determine whether they can be used as papermaking fillers.The results show that TiO₂/opal can replace the application of titanium dioxide in papermaking.TiO₂/SiO₂ composite has outstanding performance in improving the whiteness and retention of paper.