• 펄프종이기술
• /
• 제43권5호
• /
• pp.11-16
• /
• 2011

This study was aimed to apply thermochromic and photochromic pigments to coating color and to develop a speciality functional coated layer. Two special pigments were added to a conventional coating color. The effects of the special pigments on coating color properties such as water rerention, low-shear viscosity were evaluated. Also the color changes of coated paper was observed under various circumstances. The results showed that the special pigments didn't influence the coating color properties. The coated paper with the special pigments showed four different colors, under various circumstances, implying that thermochromic and photochromic pigments can be used to produce a security paper.

• 한국염색가공학회지
• /
• 제8권1호
• /
• pp.73-82
• /
• 1996

The photochromic dye(spiroxazine, Blue) as a susceptible material was synthesized by condensing 1-nitroso-$\beta$-naphthol with indoline. The melting point of the synthesized spiroxazine dye was 254$^{\circ}C$. Irradiation with ultraviolet light had effect on reversible coloration reaction. The photochromic dye microcapsules were produced by in situ polymerization using urea-formaldehyde prepolymer. The average diameter of the microcapsule was 2.94$\mu$m. The dyeability and washing fastness of the photochromic microcapsule fibers were increased by the pretreatment of cationic agent.

• 한국염색가공학회지
• /
• 제18권2호
• /
• pp.24-30
• /
• 2006

The photosensitive spiroxazine compound and the electrosensitive viologen compound were prepared to examine their practical application feasibilities and behaviors. These dyes represent corresponding chromism effects related to their own characteristics of the dye molecules. Thus, the prepared dyes were characterized and their absorption spectra were also investigated. Besides, an interest on direct spiroxazine exhaustion to the polyamide substrates and its photochromic effects within the fiber molecules were determined. The photochromic reaction on the substrates was clearly observed and its reversible decoloration behaviors responded.

• Macromolecular Research
• /
• 제13권4호
• /
• pp.321-326
• /
• 2005

Photochromic diarylethene polymers (DPs) in which 1,2-bis(2-methylbenzo[b ]thiophene-3-yl)hexafluorocyclopentene (BTF6) were covalently grafted onto the polymer main chain as pendant photochromic units were newly synthesized and their photochromic properties were investigated using steady-state and picosecond timeresolved spectroscopies. Polysiloxanes substituted with BTF6 molecules were prepared by sol-gel process using a mixture of tetraethoxysilane (TEOS), a silylated BTF6, and an organically modified silane precursor in the presence of HCl. The polysiloxane film (DP1) prepared from $\omega-methoxy$ poly(ethylene glycol) 3-(triethoxysilyl) propylcarbainate (MPGSC) as the silane precursor showed a much lower glass transition temperature than that (DP2) from heptadecafluorodecyltrimethoxysilane (HDFTMS). The ring-closure quantum yields of DP1 and DP2 were determined to be 0.20 and 0.02, respectively. Such a large difference in the quantum yield was attributed to the polymer matrix environment of the free inner volume.

• Bulletin of the Korean Chemical Society
• /
• 제19권3호
• /
• pp.308-313
• /
• 1998

A thermally irreversible photochromic system, 2,3-bis(2,4,5-trimethyl-3-thienyl)maleic anhydride (MTMA), has been studied by semi-empirical molecular orbital methods. There are one pair of stable conformations for the closed-ring form and three pairs for the open-ring form, each pair consisting of two mirror-image conformations. Interconversion between the parallel and anti-parallel conformations of the open-ring form is restricted due to high energy barriers. Only the anti-parallel conformation appears to be responsible for photochromic cyclization. Thermostability of the compound is attributed to an avoided crossing at high energy in the ground states of the isomers, whereas the photoreactivity can be explained by the mutually connected excited singlet (S1) states of the isomers, forming a double well potential with a low energy barrier. The large solvent effects can be partly explained with the low dipole moment of the anti-parallel conformation of MTMA in the S1 state. The large variation of quantum efficiency suggests that excess vibronic energy can be utilized to provide the activation energy for the photochromic reaction.

• Bulletin of the Korean Chemical Society
• /
• 제35권11호
• /
• pp.3381-3384
• /
• 2014

• 한국염색가공학회:학술대회논문집
• /
• 한국염색가공학회 2009년도 제41차 학술발표회
• /
• pp.117-118
• /
• 2009

Photochromic dye의 광안정성을 향상시키기 위해 다양한 형태의 산화방지제 및 자외선흡수제를 사용하고 있다. PMMA를 MEK에 녹이고 photochromic dye, 다양한 형태의 산화방지제 및 자외선흡수제를 첨가하여 film 조성액을 만들고 PET film에 coating하여 도막을 만들어 광변색소의 안정성을 관찰하였다. 산화방지제 및 자외선 흡수제의 종류에 따른 광변색소의 변색특성을 관찰하였으며, 농도에 따른 광변색소의 광안정성을 관찰하였다.

• Bulletin of the Korean Chemical Society
• /
• 제23권7호
• /
• pp.957-963
• /
• 2002

We successfully synthesized the addition-type polynorbonenes (PNB) exhibiting photochromic properties and excellent thermal stability. Three norbornene-based monomers with different azobenzene moiety (R=NO2, H,OCH3) were synthesized by transesterification method. The corresponding PNB copolymers were synthesized by transition metal-catalyzed addition polymerization method, and characterized by GPC, UV-Vis spectroscopy, NMR, and thermal analysis. For comparison of the photochromic properties depending on the rigidity of polymer backbone, we prepared the polymethylmethacrylate (PMMA) copolymer with the corresponding azobenzene moiety. We investigated the photoisomerization behavior by means of optical muitichannel analyzer with Xe lamp as well as real-time UV-Vis spectroscopy with high-pressure mercury lamp. Among three PNB copolymers, a polymer with azobenzene (R=H) was the most adaptable for observation of photoisomerization behavior. It was found that the rate of photoisomerization and relaxation depended on the structure of azobenzene chromophore, rather than that of polymer backbone.

• 통합자연과학논문집
• /
• 제11권1호
• /
• pp.39-43
• /
• 2018

Poly(hydroxyethyl methacrylate)-based hydrogels were surface-functionalized with spiropyran (SP) derivatives to obtain photochromic contact lenses. The contact lens reversibly changes from colorless to purple as response to UV light since colorless ring-closed SP state converts to purple ring-opened merocyanine (MC) state under UV light irradiation. The purple contact lens emits red light at 640 nm. Importantly, the presence of SP segments did not significantly affect the equilibrium water content (EWC) of the lens. SP-functionalized hydrogel lenses may find potential applications in developing light-adaptive ophthalmic materials.

• 한국염색가공학회지
• /
• 제7권4호
• /
• pp.97-104
• /
• 1995

The photochromic dyes(spiroxazine) as a susceptible material were synthesized by condensing 1-nitroso-$\beta$-naphthol with piperidine. The melting point of the synthesized spiroxazine dye was 245$^{\circ}C$. Irradiation with ultraviolet light had effect on reversible coloration reaction. The photochromic dye microcapsules were produced by interfacial precipitation method using polyvinylalcohol and ethylcellulose. The average diameter of microcapsules was 5.4$\mu$m. The dyeability and fastness of dyeings of the microcapsule fibers were increased by pretreatment of the cationic agent.