• Journal of the Semiconductor & Display Technology
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• v.16 no.1
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• pp.45-51
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• 2017

Poly(urethane acrylate) siloxane oligomers with Interpenetrating polymer netwoked nanoparticles were prepared to synthesize hard coating solution by reaction with diisocyanates. The diisocyanate combined siloxane hard coating solution showed more flexibility than the siloxane solution. In addition, diisocyanate resulted in improvement of curl property and surface hardness in the siloxane solution. Of the used diisocyanates, isophorone diisocyanate and acryloyloxy ethyl diisocyanate were good for UV hard coating solution. This effect will decrease brittleness in the siloxane solution using for plastic display plate.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.3
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• pp.259-265
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• 2006

We polymerized material of AA(Acrylic acid) and BMA(butyl methacrylate) to make up for the weak points of hydrogel contact lens. The synthesis process of silicone synthesis is as follows. Acrylate-PDMS(Polydimethylsiloxane)-Urethane prepolymer was composed after Diisocynate reacted with HEMA(2-hydroxyethylmethacrylate) under the catalyst and it reacted again with bis(hydroxyalkyl) terminated poly(dimethylsiloxane) with high oxygen transmissibility characteristics. HEMA(2-hydroxyethylmethacrylate) was used to make prepolymer that can be polymerized and the urethane was used to improve elasticity and oxygen transmissibility, copolymerization was performed with conventional hydrogel contact lens materials to make silicone hydrogel contact lens with higher oxygen transmissibility. For manufacturing of contact lens, We added BMA(Butyl methacrylate) with better elasticity and flexibility, and AA(Acrylic acid) with higher moisturizing to used contact lens materials. AIBN (Azobis2-methylpropionitrile) as initiator and EGDMA(Ethylene Glycol Dimethacrylat) as crosslinking agent were used and the lens with higher oxygen transmissibility and better moisturizing were manufactured complying with basic contact lens properties, which have several combination trial of each monomer characteristics. Compounding SN which included SILICONE, HEMA, NVP and EGDMA etc was showed by swelling ratio of 9.38% and water content of 23.7%. SN was showed by swelling ratio of 9.38%, water content of 23.7% and a visible ray transmissibility of 89%. SB which added BMA in the SN was showed by swelling ratio of 12.50%, water content of 18.56% and a visible ray transmissibility of 88%. SAB which added both AA and BMA in the SN was showed by swelling ratio of 8.33%, water content of 12.93% and a visible ray transmissibility of 88%.

• Journal of the Korean Society of Visualization
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• v.5 no.1
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• pp.3-8
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• 2007

We present simple methods for fabricating high aspect-ratio polymer nanostructures on a solid substrate by rigiflex lithography with tailored capillarity and adhesive force. In the first method, a thin, thermoplastic polymer film was prepared by spin coating on a substrate and the temperature was raised above the polymer's glass transition temperature ($T_g$) while in conformal contact with a poly(urethane acrylate) (PUA) mold having nano-cavities. Consequently, capillarity forces the polymer film to rise into the void space of the mold, resulting in nanostructures with an aspect ratio of ${\sim}4$. In the second method, very high aspect-ratio (>20) nanohairs were fabricated by elongating the pre-formed nanostructures upon removal of the mold with the aid of tailored capillarity and adhesive force at the mold/polymer interface. Finally, these two methods were further used to fabricate micro/nano hierarchical structures by sequential application of the molding process for mimicking nature's functional surfaces such as a lotus leaf and gecko foot hairs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1773-1777
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• 2010

The Application of UV curing technique for poly (vinyl chloride) (PVC) floor tiles coating has improved the quality of PVC floor. Several formulations were made including acrylated oligomers based on a polyurethane were blended with reactive monomers, photoinitiators and other additives. The used oligomers are commercial aliphatic urethane acrylates. Thin films were prepared on PVC tiles by bar coating with different formulations using UV radiation. The coating resins were characterized by FTIR. The properties of UV-cured films such as gloss and adhesion were examined. The properties of UV-cured films dependent on the influence of composition and processing conditions was studied.

• Polymer(Korea)
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• v.30 no.5
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• pp.437-444
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• 2006

Reactive hydroxypropyl methylcellulose phthalate (reactive HPMCP) was synthesized by using a stepwise urethane reaction with isophorone diisocyanate (IPDI) and 2-hydroxyethyl moth acrylate (HEMA). Molecular weight, acid number, and critical micelle concentration (CMC) of the synthesized reactive HPMCP and pristine HPMCP were measured and used as a polymeric surfactant in the emulsion polymerizations of styrene. In the preparation of HPMCP-hybrid poly styrene nanoparticles, 6, 9, 12, 18, and 24 wt% of HPMCPs were introduced, and the maximum rate of polymerization ($R_{p,max}$), the average number of radicals per particle (n), particle size distribution were investigated. In addition, core - shell morphology of the nanoparticles were observed by using TEM and their thermal stabilities were measured by using TGA. Reactive HPMCP showed higher $R_{p,max}$, smaller particle size, larger values of n and gel contents as compared with pristine HPMCP, due to the vinyl groups from HEMA, which can be reacted with styrene oligomers, in the reactive HPMCP.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.365-365
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• 2010

Similar to the superhydrophobic surfaces of lotus leaf, water strider leg is attributed to hierarchical structure of micro pillar and nano-hair coated with low surface energy materials, by which water strider can run and even jump on the water surface. In order to mimick its leg, many effort, especially, on the fabrication of nanohairs has been made using several methods such as a capillarity-driven molding and lithography using poly(urethane acrylate)(PUA). However most of those effort was not so effective to create the similar structure due to its difficulty in the fabrication of nanoscale hairy structures with hydrophobic surface. In this study, we have selected a low surface energy polymeric material of polytetrafluoroethylene (PTFE, or Teflon) assisted with surface modification of CF4 plasma treatment followed by hydrophobic surface coating with pre-cursor of hexamethyldisiloxane (HMDSO) using a plasma enhanced chemical vapor deposition (PE-CVD). It was found that the plasma energy and duration of CF4 treatment on PTFE polymer could control the aspect ratio of nano-hairy structure, which varying with high aspect ratio of more than 20 to 1, or height of over 1000nm but width of 50nm in average. The water contact angle on pristine PTFE surface was measured as approximately $115^{\circ}$. With nanostructures by CF4 plasma treatment and hydrophobic coating of HMDSO film, we made a superhydrophobic nano-hair structure with the wetting angle of over $160^{\circ}C$. This novel fabrication method of nanohairy structures has been applied not only on 2-D flat substrate but also on 3-D substrates like wire and cylinder, which is similarly mimicked the water strider's leg.