Study On Surface Modification Of Rigid Gas Permeable Contact Lens By Plasma Technology

Fluorosilicone acrylate (FSA) as one kind of rigid gas permeable contact lens (RGPCL) materials, is an effective tool to slow the progression of myopia in youngsters. FSA has high gas permeability, unfortunately its surface is hydrophobic because of the fluorine and silicone group in the structure, which could result in protein deposition easily. In this thesis, in order to improve the surface hydrophilicity and the resistance to protein deposition, plasma treatment and plasma grafting polymerization were used to modify the FSA RGP contact lens surface. And the changes of surface structures and properties were characterized by X-ray photoelectron spectroscopy (XPS) and surface morphology observation, hydrophilicity measurement, refractive index test, aging effect study and protein deposition study.NH3/O2 plasma treatment were used to modify the FSA RGP contact lens surface. XPS analysis indicated that there were break of some bonds and formation of hydrophilic groups during plasma treatment. Hydrophilicity measurement showed that there was a great improvement of hydrophilicity after plasma treatment. The lens before and after plasma treatment exhibited a flat and smooth surface morphology. The refractive index test showed that there was a very little change after plasma treatment. The contact angles of lens treated by direct NH3/O2 plasma treatment decreased with the prolongation of storage time.NH3/O2 plasma grafting polymerization were used to graft 2-methacryloyloxyethyl phosphorylcholine (MPC), which has excellent hydrophilicity, biocompatibility, resistance to protein deposition, to the FSA RGP contact lens surface. XPS analysis indicated that MPC was successfully grafted to the lens surface. Hydrophilicity measurement showed that there was a great improvement of hydrophilicity after plasma grafting. The lens before and after plasma grafting exhibited a flat and smooth surface morphology. The refractive index test showed that there was a very little change after plasma grafting. Protein deposition study indicated that the resistance to protein deposition of the lens after modification improved.NH3/O2 plasma grafting polymerization were used to graft poly (ethylene glycol) diacrylates (PEGDA), which has excellent hydrophilicity, biocompatibility, resistance to protein deposition, to the FSA RGP contact lens surface. XPS analysis indicated that PEGDA was grafted to the lens surface. Hydrophilicity measurement showed that there was a great improvement of hydrophilicity after plasma grafting. The refractive index test showed that there was a very little change after plasma grafting. Protein deposition study indicated that the resistance to protein deposition of the lens after modification improved, and the modification effect of the lens grafting PEGDA10000 was better.