목적 : 본 연구는 세륨(IV)-지르코늄(IV) 산화물 나노입자를 사용하여 콘택트렌즈를 제조한 후, 안의료용 기능성 렌즈로의 사용 가능을 확인 위해 제조된 렌즈의 물성을 비교 분석하였다. 방법 : 2-Hydroxyethyl methacrylate에 나노 세륨-지르코늄 산화물(cerium(IV)-zirconium(IV) oxide)을 첨가하여 공중합 한 후 물성을 측정하고, 친수성 단량체인 methacrylic acid(MA)를 추가로 첨가하여 물성을 측정, 비교하였다. 결과 : 다양한 비율의 세륨(IV)-지르코늄(IV) 산화물 나노입자와 MA를 첨가한 렌즈의 물성을 평가한 결과, UV-B 투과율은 40.95~66.26%, 굴절률 1.4163~1.4357, 함수율 37.44~47.18%, 접촉각 36.87~56.36°, 인장 강도 0.0612~0.561 kgf/mm², 표면거칠기 7.70~8.72 nm로 각각 측정되었다. 나노입자 및 MA 첨가는 습윤성, 인장강도 및 중합안정성을 향상시키고, UV-B 투과율과 표면거칠기를 감소시켰으며, 황색포도상구균에 대한 항균 성이 확인되었다. 결론 : 세륨(IV)-지르코늄(IV) 산화물 나노입자에 MA를 첨가하여 제조한 렌즈가 중합 안정성, 내구성, 습윤성 을 향상시키는 것을 확인하였으며, 따라서 안의료용 기능성 콘택트렌즈 소재로 활용할 수 있을 것으로 판단된다.

Cerium oxide decorated on nickel hydroxide anchored on reduced graphene oxide (Ce-Ni(OH)2/rGO) composite with hexagonal structures were synthesized by facile hydrothermal method. Fourier transform infrared spectroscopy (FT-IR), highresolution transmission electron microscopy with selected area diffraction (HRTEM-SAED), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer– Emmett–Teller (BET) surface area analysis and electrochemical technology were used to characterize the composite. Due to its unique two-dimensional structures and synergistic effect among Ce2O3, Ni(OH)2 and rGO components indicated twodimensional hexagonal nano Ce-Ni(OH)2/rGO composite is promising electrode material for improved electrochemical H2O2 sensing application. From 50 to 800 μM, the H2O2 concentration was linearly proportional to the oxidation current, with a lower detection of limit of 10.5 μM (S/N = 3). The sensor has a higher sensitivity of 0.625 μA μM−1 cm− 2. In addition, the sensor demonstrated high selectivity, repeatability and stability. These findings proved the viability of the synthetic method and the potential of the composites as a H2O2 sensing option.

The potential application of ultrafine cerium oxide (ceria, ) as an oxygen gas sensor has been investigated. Ceria was synthesized by a thermochemical process: first, a precursor powder was prepared by spray drying cerium-nitrate solution. Heat treatment in air was then performed to evaporate the volatile components in the precursor, thereby forming nanostructured having a size of approximately 20 nm and specific surface area of 100 . After sintering with loosely compacted samples, hydrogen-reduction heat treatment was performed at 773K to increase the degree of non-stoichiometry, x, in . In this manner, the electrical conductivity and oxygen-response ability could be enhanced by increasing the number of oxygen vacancies. After the hydrogen reduction at 773K, was obtained with nearly the same initial crystalline size and surface. The response time measured at room temperature was extremely short at 4 s as compared to 14 s for normally sintered . We believe that this hydrogen-reduced ceria can perform capably as a high-performance oxygen sensor with good response abilities even at room temperature.

The nanostructured cerium oxide powders were synthesized by spray thermal decomposition process for the use as the raw materials of resistive oxygen sensor. The synthesis routes consisted of 1) spray drying of water based organic solution made from cerium nitrate hydrate () and 2) heat treatment of spray dried precursor powders at in air atmosphere to remove the volatile components and identically to oxidize the cerium component. The produced powders have shown the loose structure agglomerated with extremely fine cerium oxide particles with about 15 nm and very high specific surface area (). The oxygen sensitivity, n ( and the response time, measured at in the sample sintered at , were about 0.25 and 3 seconds, respectively, which had much higher performances than those known in micron or sized sensors.