졸-겔공정에 의하여 다공성 리소시놀/포름알데히드(RF) 유기 에어로겔과 RF-폴리스티렌(PS) 복합 에어로겔을 제조하는 방법을 제안하였다. 또, TMOS-아닐린 유기-무기 복합 에어로겔을 제조하여 전도성 에어로겔의 합성 가능성을 확인하였다. 기공도와 표면적 등의 물리적인 특성의 분석결과 초임계 건조법의 이용이 필요한 RF 에어로겔은 저밀도, 높은 다공도와 표면적 등의 특성을 갖고 있으나 충격에 대한 구조적 안정성이 낮은 단점을 지니고 있었다. 이와 같은 단점을 개선하기 위하여 에멀젼 중합에 의하여 PS 발포체를 제조하고 여기에 RF 혼합액을 가압 침투시켜 숙성 증발건조하여 RF/PS 복합 유기 에어로겔을 제조하였다. RF/PS 에어로겔은 RF 에어로겔에 비하여 다공도, 기공의 크기 및 구조의 균일성이 다소 떨어지지만 습윤겔의 용매치환이나 초임계 건조없이 일반 증발건조가 가능하여 기계적 강도가 향상되어진 것으로 밝혀졌다. RF/PS 에어로겔의 셀과 기공의 크기 및 구조는 PS 에멀젼 중합조건시 에멀젼화제의 양과 반응온도 그리고 교반속도에 의해 제어가 가능하였다.

Synthetic processes of organic resorcinol/formaldehyde(RF) aerogel and RF-polystyrene(PS) composite aerogel were proposed based on sol-gel processing technique. Also, by synthesizing TMOS-aniline composite aerogel, the potential utility of aerogel for conducting materials was conformed. RF aerogel obtained by supercritical fluid drying was found to retain low density, high porosity and specific surface properties. However, it shows intrinsic structural fragility against impact. To improve such a drawback with the RF aerogel, a new organic composite RF aerogel with polystyrene(RF/PS) was also made. In synthesizing the RF/PS aerogel, RF solution was impregnated into PS foam, which was obtained by an emulsion polymerization. Then the RF/PS wet gel was cured and residual liquid in the internal pores of the gel was removed by a conventional drying. In contrast to the RF aerogel, we found that the RF/PS aerogel showed relatively lower homogeneties in its porosity, pore sizes and pore structures than the RF. However, it showed significantly the enhanced mechanical strength and the improved machining aspect. Furthermore the overall process of obtaining RF/PS was simpler than the case of RF aerogel. We also found that the average size of pores of the RF/PS depended on the conditions of the polymerization. Also, the morphology and stability of the PS foam was controllable by the amount of changing emulsifying agent, the reaction temperature and stirring rate.

RF/PS Aerogel TMOS/Aniline Aerogel Organic Aerogel Supercritical Drying

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