Tham khảo tài liệu 'coatings technology handbook episode 3 part 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 96 Solgel Coatings Lisa C. Klein Rutgers-The State University of New Jersey The Solgel Thin Film Optical Coatings Electronic Coatings Abrasion Coatings Protective Coatings Porous Coatings Composites Introduction Solgel processing is now well accepted as a technology for thin films and coatings. Indeed the solgel process is an alternative to chemical vapor deposition sputtering and plasma spray. Not only have solgel thin films proved to be technically sound alternatives they have been shown to be commercially viable as well. The technology of solgel thin films has been around for over 30 years. The process is quite simple. A solution containing the desired oxide precursor is prepared with a solvent and water. It is applied to a substrate by spinning dipping or draining. The process is able to apply a coating to the inside and outside of complex shapes simultaneously. The films are typically 1 im uniform over large areas and adherent. The equipment is inexpensive especially in comparison to any deposition techniques that involve vacuum. Coatings can be applied to metals plastics and ceramics. Typically the coatings are applied at room temperature though most need to be calcined and densified with heating. Both amorphous and crystalline coatings can be obtained. The Solgel Process The solgel process is the name given to any one of a number of processes involving a solution or sol that undergoes a solgel transition. A solution is truly a single-phase liquid while a sol is a stable suspension of colloidal particles. At the transition the solution or sol becomes a rigid porous mass by destabilization precipitation or supersaturation. The solgel transition to a rigid two-phase system is not reversible. The first step is choosing the right reagents. To illustrate this silica will be used as the model system. Of the available silicon alkoxides .
