Modification of Teflon film
For Teflon film which has been formed, the following methods can be used to change or increasing the some properties of thin films, in order to achieve the experiment or industrial demand.
(1) The PTFE impregnated in some metal hydroxide colloid solution, such as iron hydroxide and hydroxide tin hydroxide colloid, gel ion deposition in PTFE membrane surface, can increase the wetting Angle.
(2) Iron hydroxide colloid adsorbed to the PTFE membrane, and polymerization of acrylic acid (AA) hydrophilic monomers, hydrophilic strong PTFE microporous membrane can be obtained.
(3) With the inert gas such as argon, helium plasma processing PTFE membrane, cohesive force than before treatment increased 10 times. PTFE membrane after plasma treatment, and then AA chemical treatment, AA of strong hydrophilic is grafted to the surface of PTFE, and makes the PTFE film is of good surface infiltration characteristics.
This paper reviews laser pulse deposition, pyrolytic amorphous PTFE precipitation method and impregnated method of coated Teflon film. In addition to these three methods, method of spin coating is commonly used with Teflon film, which obtain the quickest method, it is not the limitation on the sedimentary materials without a substantial, the thickness of thin film gets below the dip coating method. Through the above analysis, in the laser pulse deposition method, using different membrane characteristics of target material to produce slightly different. Powder compacting of PTFE as a target material, the thin film in high resistivity, and high temperature of unpolarized light has high transparency; polished block of PTFE as a target material, the thin film is lower for visible light transparency, in the form of cohesion is very poor. Pyrolysis of PTFE amorphous precipitation, the thin film has many holes, but after condensation formed by light transparent film with amorphous structure, and no hole under high magnification. Method of dip coating can change the deposition of thin film microstructure, operation is easy, high cost performance is higher. These methods have their advantages and disadvantages, in practice, should according to different conditions and demand to choose different coating methods. For example, in the double liquid zoom lens experiments, choose the tantalum pentoxide zoom lens as a double liquid dielectric layer, dielectric layer outside should be coated with a layer of hydrophobic membrane. According to the above advantages and disadvantages of various coating method, considering the base is a special cylindrical, this study thinks that dip coating technique is more suitable for double liquid zoom lens.