• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.319-319
• /
• 2010

Dye-sensitized solar cells (DSSCs) based on plastic substrates have attracted much attention mainly due to extensive applications such as ubiquitous powers, as well as the practical reasons such as light weight, flexibility and roll-to-roll process. However, conventional high temperature fabrication technology for glass based DSSCs, cannot be applied to flexible devices because polymer substrates cannot withstand the heat more than $150^{\circ}C$. Therefore, low temperature fabrication process, without using a polymer binder or thermal sintering, was required to fabricate necked $TiO_2$. In this presentation, we proposed polymer-inorganic composite photoelectrode, which can be fabricated at low temperature. The concept of composite electrode takes an advantage of utilizing elastic properties of polymers, such as good impact strength. As an elastic material, poly(methyl methacrylate) (PMMA) is selected because of its optical transparency and good adhesive properties. In this work, a polymer-inorganic composite electrode was constructed on FTO/glass substrate under low temperature sintering condition, from the mixture of PMMA and $TiO_2$ colloidal solution. The effect of PMMA composition on the photovoltaic property was investigated. Then, the enhanced mechanical stability of this composite electrode on ITO/PEN substrate was also demonstrated from bending test.

• Macromolecular Research
• /
• v.17 no.11
• /
• pp.894-900
• /
• 2009

This study examined the charge carrier photogeneration and hole transport properties of blends of poly (9-vinylcarbazole) (PVK), $\pi$-conjugated polymer, with different weight proportions (0~29.4 wt%) of (PEA)$VOPO_4{\cdot}H_2O$ (PEA: phenethylammonium cation), a novel organic-inorganic hybrid material, using IR, UV-Vis, and energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), steady state photocurrent (SSPC) measurement, and atomic force microscopy (AFM). The SSPC measurements showed that the photocurrent of PVK was reduced by approximately three orders of magnitude by the incorporation of a small amount (~12.5 wt%) of (PEA) $VOPO_4{\cdot}H_2O$, suggesting that hole transport occurred through the PVK carbazole groups, whereas a reverse trend was observed at high proportions (>12.5 wt%) of (PEA)$VOPO_4{\cdot}H_2O$, suggesting that transport occurred via (PEA)$VOPO_4{\cdot}H_2O$ molecules. The transition to a trap-controlled hopping mechanism was explained by the difference in ionization potential and electron affinity of the two compounds as well as the formation of charge percolation threshold pathways.

• Elastomers and Composites
• /
• v.24 no.4
• /
• pp.276-289
• /
• 1989

This study deals with both effects of inorganic fillers to vulcanized rubbers such as NR, CR, EPDM, NBR & SBR and inorganic characteristics of domestic fillers in comparision with hard clay produced in the USA. The results were as follows. 1. Main ingredient of domestic clay "Ha-dong clay" was Halloysite, "No-ha Island" was Pyrophyllite with $\alpha$-Quartz, and both of "Hard clay" & "Hwa-soon clay" were proved to be Kaolinite by XRD, DT-TGA and chemical analysis by XRF. 2. Tensile strength value of SBR compounded with these fillers, was Hard clay $146kg\;f/cm^2$, Kaolinite $123kg\;f/cm^2$, Pyrophyllite $82kg\;f/cm^2$, Halloysite $80kg\;f/cm^2$, precipitated $CaCO_3\;27kg\;f/cm^2$, and ground $CaCO_3$ was $21kg\;f/cm^2$. These results showed the increase of seven times according to filler species. 3. The physical properties of non-crystalline rubbers, such as SBR, NBR & EPDM, compared with NR & CR, have been considerably changed according to crystalline phase, particle size, shape and surface structure of fillers. Especially, tensile strength value in case of SBR & EPDM, was differentiated about 1.5 times by the particle size of fillers. 4. In SBR, physical properties of rubber compounded with Kaolinite which was surface treated with fatty acid and silane, almost approach to the value of hard clay. 5. Delayed cure time of Kaolinite and decrease of rubber properties by $CaCO_3$ can be improved by blending kaolinite & $CaCO_3$ in the ratio of 2:1.

• Journal of Adhesion and Interface
• /
• v.16 no.1
• /
• pp.6-14
• /
• 2015

In this study, physically and chemically stable core-crosslinked amphiphilic polymer (CCAP) nanoparticles were prepared using amphiphilic reactive precursors via soap-free emulsion process. Obtained CCAP nanoparticles were used as templates for synthesis of nanostructured $TiO_2$ nanoparticles. First, CCAP nanoparticles dispersed aqueous solutions were mixed with titanium isopropoxide to prepare stable organic-inorganic hybrid sols, and then obtained sols were spin coated onto glass substrate to prepare hybrid thin films onto glass, and then hybrid thin films were calcinated at various temperature to remove CCAP. Nanostructure of calcinated thin fims were examined by SEM. To study effect of CCAP nanoparticles on nanostructure of $TiO_2$ nanoparticles, the morphology of $TiO_2$ nanoparticles prepared using various CCAP templates was compared with that of $TiO_2$ nanoparticles prepared using conventional organic template, nonionic surfactant, Triton X-100.

• Journal of Hydrogen and New Energy
• /
• v.32 no.6
• /
• pp.524-533
• /
• 2021

In this study, a series of anion conductive organic/inorganic composite membranes with excellent ionic conductivity and chemical stability were prepared by introducing graphene oxide (GO) inorganic nanofiller into the quaternized poly(phenylen oxide (Q-PPO) polymer matrix. The fabricated organic/inorganic composite membranes showed higher ionic conductivity than the pristine membrane. In particular, Q-PPO/GO 0.7 showed the highest ionic conductivity value of 143.2 mS/cm at 90℃, which was 1.56 times higher than the pristine membrane Q-PPO (91.5 mS/cm). In addition, the organic/inorganic composite membrane showed superior dimensional stability and alkaline stability compared to the pristine membrane, and the physicochemical stability was improved as the content of inorganic fillers increased. Therefore, we suggest that the as-prepared organic/inorganic composite membranes are very promising materials for anion exchange membrane applications with high conductivity and alkaline stability.

• Applied Chemistry
• /
• v.9 no.2
• /
• pp.25-28
• /
• 2005

To evaluate the dental restorative application of polymer composites filled with hydroxyapatite (HAP) which is an inorganic component of human bone material, dental properties of the polymer composites were investigated. A visible light system was utilized to activate the acrylate resin matrix of the composites. Maximum loading percentage of HAP in composite was 65 wt% and the depth of cure was 6.0 mm which can be applicable for dental restoration. With increasing the HAP content, degree of conversion of polymer composites was slightly decreased, however, polymerization shrinkage value was not varied. Diametral tensile strength value was enhanced with an increase of HAP content, however, there was no strict trend between flexural strength and HAP concentration. Anyhow, polymer composites prepared herein have superior mechanical properties sufficient specifications applicable to dental materials.

• Polymer Science and Technology
• /
• v.23 no.3
• /
• pp.260-272
• /
• 2012

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.917-919
• /
• 2003

The effect of conducting carbon layer on the performance of AC thin film EL display was examined. It was found that incorporation of small amount of carbon nano-tube and conducting additive greatly improve the luminance of the inorganic EL compared to the one with only conducting carbon black.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2012.05a
• /
• pp.59.2-59.2
• /
• 2012

Polymer solar cells utilize bulk heterojunction (BHJ) type photo-active layer in which the electron donating polymer and electron accepting $C_{60}$ derivatives are blended. We found there is significant charge recombination at the interface between the BHJ active layer and electrode. The charge recombination at the interface was effectively reduced by inserting wide band gap inorganic interfacial layer, which resulted in efficiency and stability enhancement of BHJ polymer solar cell.

• Polymer Science and Technology
• /
• v.21 no.5
• /
• pp.459-465
• /
• 2010