This study was planned considering the chain length, hydrophilicity, and hydrophobicity of the additives to be used in the polymerization, while various hydrogel contact lenses that use various additives with similar water contents were manufactured before their optical and physical properties were compared and analyzed. With regard to the additives required for manufacturing high-, medium-, and low-water content lens groups, HEA, PVP, and NMV were used as additives for preparing the high-water content lens group, HEMA,HPMA and BD were used for the medium-water content lens group. For the low-water content lens group, BMA, BDDA, and Bis-GMA were used, respectively.
The measurements of the contact angles, however, showed a different wettability value for each lens with a similar water content. Also, the change tendency of the lens curvature according to the change of time showed that the change amount became larger and the recovery time became longer from the lens samples with a lower water content to those with a higher water content. Based on these results that will be helpful for the study of hydrogel contact lenses.
The basic hydrogel contact lens material with addition of HEA, HEMA, HPMA with the cross-linker EGDMA and the initiator AIBN were used for copolymerization. As a result of the molecular length influenced on the refractive index and water content of the polymerized material.
The characteristics of hydrogel contact lens polymerized with additived of glycerin and PVP in the basical hydrogel contact lens material were evaluated. Results of this study, the produced polymers is suitable for conventional hydrogel contact lens with high wettability. And also, glycerin minimalized the changes of refractive index and water content and the increased the wettability of the hydrogel contact lens materials.
PEGMEMA was applied as an additive in the primary polymerization, which resulted in the higher water content and wettability of hydrogel contact lenses. The use of 2,4-dihydroxybenzophenone as an additive in the secondary polymerization provided the hydrogel contact lenses with the feature of blocking ultraviolet rays.
For the preparation of high functional silicone hydrogel lens materials, two silicone monomer used in the presence of HEMA and HPMA. Silicone monomer containing HEMA and HPMA was expected to be used usefully as a material for fabricating high oxygen permeability silicon hydrogel contact lens.
The physical and optical characteristics of silicon hydrogel contact lens containing silicon monomer and the basic hydrogel lens material containing PEGMEMA were examined. For manufacturing silicone hydrogel contact lens, silicone monomer, DMA were copolymerized. This material is expected to be used usefully as a material for the water content development of silicone hydrogel contact lens without affecting the contact angle.
Hydrogel contact lenses containing fluorine-substituted aniline group, titanium silicon oxide NPs, and silver NPs were copolymerized, and the physical and optical properties of the hydrogel lenses were measured. Also, the addition of aniline, titanium silicon oxide, and silver NPs allowed the hydrogel contact lenses to block UV. These results show that the produced macromolecule can be used as hydrophilic lenses for ophthalmologic purposes that can block UV.
To produce a highly functional hydrogel lens, vinylpyrrolidone(VP) material was added to a basic hydrogel material, and they were copolymerized using WO3 and SiND as additives. Therefore, when vinylpyrrolidone and nanoparticles are added to the basic hydrogel material, the manufactured lens has a high water content and can be used as an appropriate material for highly functional tinted contact lens with an ultraviolet blocking effect.
For manufacturing hydrogel lens, HEMA, PVP, Bis-GMA, GO NPs were copolymerized. As a result, when GO NPs were added to the Ref. and Ref.-B samples, the wettability increased due to the hydrogen bonding between the GO and the water molecules, which were distributed on the surface. In the case of Ref.-P containing PVP, the probability of hydrogen bonding with the water molecules on the surface was lowered as hydrogen bonding was induced by the nitrogen of PVP and the carboxyl group of the GO NPs; thus, the wettability somewhat decreased. Therefore, GO, which has excellent abrasion resistance, is considered useful as a material for hydrogel contact lenses with excellent wettability and strength when added to the general hydrogel lens materials other than hydrophilic materials like PVP.
ITO NPs is highly electroconductive, and it is possible to use thin ITO to create a transparent protective film in various field. When PEGMEMA, 2,4-dihydroxybenzophenone, and ITO NPs is used as additives, it is possible to manufacture high-functional hydrogel contact lenses with the features of high water content, high wettability and UV ray and electromagnetic wave blocking effect.
And also, the PEGMEMA and Platinum NPs were used as additive. This material is expected to be used usefully as a material for the water content development of silicone hydrogel lens without affecting the contact angle. Furthermore, the current lens coloring method used pigments, but the platinum NPs can be used to induce a coloring effect with their unique color, and they can also be used as an antibacterial material for the ophthalmologycal contact lens.