• Journal of Integrative Natural Science
• /
• v.13 no.1
• /
• pp.13-18
• /
• 2020

This study used cerium iron hydroxide nanoparticle with HEMA (2-hydroxyethyl methacrylate), the cross-linker EGDMA (ethylene glycol dimethacrylate), NVP (N-vinyl-2-pyrrolidone) and the initiator AIBN (azobisisobutyronitrile) for copolymerization. Also, the physical properties of the prepared lenses were compared, and their applicability as polymers for ophthalmic materials was experimented. The results of the measurement showed that the UV blocking rate and the wettability increased with the cerium iron hydroxide nanoparticles addition ratio, and the refractive index and water content were not affected. Thus, the produced copolymer is expected to be useful as a functional contact lens material while satisfying the basic physical properties of the hydrogel contact lens.

• Carbon letters
• /
• v.7 no.4
• /
• pp.266-270
• /
• 2006

Multi-walled carbon nanotube-poly methyl methacrylate (MWNT/PMMA) nanocomposite has been prepared by in situ polymerization of MMA dispersed with MWNTs. The MWNTs were functionalized by nitric acid and sulfuric acid treatment, and this was confirmed by FTIR spectrometer. The solution mixture of MWNTs and MMA was partially polymerized at $80^{\circ}C$, followed by the addition of AIBN and polymerization at $50^{\circ}C$. The MWNT-PMMA composite was prepared by casting the pre-polymer on the glass plate, and the optical properties have been studied using UV-vis spectrometer. The acid treated MWNTs were well dispersed in MMA with fairly good dispersion stability, while flocculation and sedimentation was observed from raw MWNTs in MMA.

• Journal of Integrative Natural Science
• /
• v.10 no.3
• /
• pp.148-153
• /
• 2017

In this study, HEMA, MMA, AA, and EGDMA were used as basic combinations for manufacturing hydrophilic lenses for ophthalmic applications. In addition, AIBN (thermal polymerization initiator), 2H2M (photo polymerization initiator), and 3-hydroxypyridine (additive) were used to manufacture hydrophilic ophthalmic lenses through thermal polymerization and photo polymerization before their physical properties were measured. The results showed that when ophthalmic lenses were prepared via thermal polymerization and photo polymerization using 3-hydroxypyridine as an additive, their optical and physical properties and surface structures were different in each case, but they all satisfied the physical properties required for ophthalmic lenses.

• Macromolecular Research
• /
• v.14 no.3
• /
• pp.324-330
• /
• 2006

Four different molecularly imprinted polymers (MIPs) were prepared using resveratrol as the template, methacrylic acid (MAA) or acrylamide (AA) as functional monomers, 2,2-azobisisobutyronitrile (AIBN) as the initiator, and thermo- or photo-induced polymerization. The ability of the different polymers to rebind selectively not only the template but also other phenols was evaluated. In parallel, the influence of the different templates and functional monomers used during polymer syntheses on the performance of the obtained MIPs was also studied through different rebinding experiments. The binding ability and selectivity of the polymer were studied by static balance method and Scatchard analysis. It was concluded that AA-based polymer by photo-induced polymerization presents the best properties to be used as a selective absorbent for the extraction of resveratrol.

• Journal of Integrative Natural Science
• /
• v.6 no.2
• /
• pp.76-81
• /
• 2013

ZnO nanoparticles and vinyl pyridine were added to the mixture of MMA (methyl methacrylate), HEMA (2-hydroxy ethyl methacrylate) and NVP (N-vinylpyrrolidone) in a mould at various concentrations. Cross-linker EGDMA (ethyleneglycoldimethacrylate) and AIBN (azobisisobutyronitrile) initiator were finally added to the mixture and then heated at $80^{\circ}C$ for 60 min to prepare high-performance hydrogel ophthalmic lens. The physical properties of the hydrogel ophthalmic material were investigated by measuring the average value of refractive index, water content and optical transmittance. The refractive index of 1.429~1.450, water content of 34~41%, and visible transmittance of 78~90% were obtained. The material is possibly used to manufacture UV-block hydrogel contact lens.

• Journal of Integrative Natural Science
• /
• v.11 no.1
• /
• pp.1-8
• /
• 2018

HEMA, AA, MMA, and EGDMA as crosslinking agent and AIBN as an initiator, and 2,4-dihydroxybenzophenone, 2-ethylhexyl-trans-4-methoxy-cinnamate, 2-hydroxy-4-(methacryloyloxy)benzophenone as additives at 0.1-1.0% ratios were used to manufacture hydrophilic ophthalmic lenses through thermal polymerization before their physical properties were measured. The results showed that the samples containing of 2,4-dihydroxybenzophenone and 2-ethylhexyl-trans-4-methoxy-cinnamate resulted in a decrease of the UV blocking performance after high-pressure sterilization whereas the sample containing 2-hydroxy-4-(methacryloyloxy)benzophenone showed no change in the UV blocking performance. It is judged that this is induced by presence or absence of an acyl functional group in benzophenone.

• Bulletin of the Korean Chemical Society
• /
• v.21 no.6
• /
• pp.595-603
• /
• 2000

Ring expansion reactions via endocyclic cleavage of cyclopropylcarbinyl radicals derived from the reaction of [1-benzyloxycarbonylbicyclo[n. 1.O]alk-(n+l)-yl] -1-imidazolethiocarboxylates with tributyltin hydride/AIBN proceeded to produce 3-cycloalkenecarboxylates in good yields. Benzyl (5'-phenoxypentyl) -3-cyclohepten-1 -carboxylate was obtained in 33% yield from the reaction of benzyl 5-methylenebicyclo [4. 1.0]- 1-carboxylates with 4-phenoxybutyl iodide under radical conditions. Selective cleavage of endocyclic bond in cyclopropane to the cyclohexane, results from stabilization of the resultant radical by the carbonyl groups, such as the benzyloxycarbonyl group, which lower the transition state energy for the final cyclopropane cleavage in the ring expansion.

• Journal of Integrative Natural Science
• /
• v.7 no.1
• /
• pp.5-10
• /
• 2014

A study that copolymerized Ag nanoparticle and furfuryl isocyanate with the crosslinking agent EGDMA (ethylene glycol dimethacrylate), HEMA (2-hydroxyethyl methacrylate), MMA (methyl methacrylate), MA (methacrylic acid) and the initiating agent AIBN (azobisisobutyronitrile) is presented. Measurement of the physical characteristics of the produced macromolecule showed that the water content is 32.08~32.67%, refractive index 1.446~1.448, visible light transparency 83.2~67.6%, contact angle $68.2{\sim}83.5^{\circ}$ and tensile strength 0.541~0.755 kgf. It is also demonstrated that the addition of Ag nanoparticles is associated with the reduction of UV-B transmittance and increase in tensile strength. The results show that the produced copolymer can be used as a material for ophthalmic lenses with durability and UV-blocking properties.

• Korean Journal of Materials Research
• /
• v.31 no.8
• /
• pp.427-432
• /
• 2021

This study uses silicone monomer, DMA, crosslinking agent EGDMA, and initiator AIBN as a basic combination to prepare hydrogel lenses using fluorine-based perfluoro polyether and iron oxide and zinc oxide nanoparticles as additives. After manufacturing the lens using iron oxide nanoparticles and zinc oxide nanoparticles, the optical, physical properties, and polymerization stability are evaluated to investigate the possibility of application as a functional hydrogel lens material. As a result of this experiment, it is found that the addition of the wetting material containing fluorine changes the surface energy of the produced hydrogel lens, thereby improving the wettability. Also, the addition of iron oxide and zinc oxide nanoparticles satisfies the basic hydrogel ophthalmic lens properties and slightly increases the UV blocking performance; it also increases the tensile strength by improving the durability of the hydrogel lens. The polymerization stability of the nanoparticles evaluated through the eluate test is found to be excellent. Therefore, it is judged that these materials can be used in various conditions as high functional hydrogel lens material.

• Journal of the Korean Chemical Society
• /
• v.64 no.6
• /
• pp.354-359
• /
• 2020

This research was conducted to analyze the compatibility of used monomers and produce the high functional contact lens material containing silicone monomers. Silicone monomer (Sil-OH), Trimethylsilylmethacrylate (TSMA) were used as additives for the basic combination of Polyhedral Oligomeric Silsesquioxane (POSS), methyl methacrylate (MMA) and methyl acrylate (MA). And also, the materials were copolymerized with ethylene glycol dimethacrylate (EGDMA) as the cross-linking agent, AIBN (thermal polymerization initiator) as the initiator. It is judged that the fabricated lenses of all combinations are optically excellent and thus used monomers have good compatibility. Measurement of the optical and physical characteristics of the manufactured hydrophilic lens material were varied in each case. Especially TSMA with POSS increases the oxygen permeability and Sil-OH with POSS increases the wettability by the addition of Sil-OH. These materials were considered to have compatibility each other, so it can be used in functional contact lens material.