Naturally occuring polysaccharide chitin was separated in clean form from skeletal pens of squids by acid and alkali treatment. Chitosan was prepared from thus prepared chitin by deacetylation with alkali, and the resulting chitosan sample had 87% of total possible acetylamino group deacetylated (degree of N-acetylation; 0.13). N-Stearoyl chitosan was then prepared by reacting the chitosan with stearic anhydride in acetic acid. Extent of N-stearoylation was 17%. This sample of N-stearoylated chitosan was soluble in anhydrous formic acid and water-swelling films could be cast. Films thus cast were of 12-13μ dry thickness and employed for ultrafilation experiments.
Rejection efficiency towards various solutes of different molecular weight including polyethylene glycols, saccharides, amino acids were examined. Molecular exclusion limit was found to be about 6,000. This value is smaller than that of chitin (10,000).
Measurements of the distribution coefficient for the various solutes correlates well with the difference in rejection efficiency toward solutes of similar molecular weights. The flux through the membranes was characterized in terms of convective and diffusive flux, and found to be the combination of both types of flux.
자연에 존재하는 키틴을, 오징어뼈를 산,알칼리 처리하여 얻은후, N-deacetylation시켜 키토산으로 만들었다. 키토산에 있어서 아민과 아세트 아미드기의 갯수비는 약 6.4대 1이었다.
키토산을 10% 초산수용액에서 Stearic anhydride와 반응시켜 N-Stearoylation을 시켰으며, 생성물의 치환도는 약 0.17이었다.
무수 포름산으로 N-Stearoylchitosan을 녹여 필름을 제조하였으며, 젖은 막의 두께는 18~22μ이고, 함수율은 15.8%였다.
얻어진 필름으로 여러가지 용질에 대한 rejection efficiency를 측정한 결과 분자량이 증가함에 따라 rejection efficency가 "S"자 모양으로 증가 하였으며 분자량 6,000정도를 Exclusion limit로 추정하였다.
간단한 아미노산의 경우, L과 D form의 이 막에 대한 투과성이 같았으며, saccharide류가 PEG류보다 rejection efficiency가 작은 이유를 분배계수로서 설명, 확인하였다.
또한, 압력과 농도에 따른 rejection efficiency의 변화추세를 검토하였고, 동 막에 대한 flux를 convective와 diffusive flow로 나누어 고찰하였다.
