Polyacrylic acid membrane which was sandwiched by cellulose acetate membranes was prepared and tested in reverse osmosis. Salt rejection was found to be a function of pressure, feed concentration, and ionic valence. It is qualitatively in agreement with a Donnan exclusion theory. Rejections of monovalent counter-ion salts increased strongly with decreasing concentration, while those of divalent counter-ion salts are not so sharp against decreasing concentration. Salts of divalent co-ion are more highly rejected than those of monovalent co-ion. It was found that salt rejections were connected with a change of pore volume or water content in membrane caused by pressure, feed concentration, and valence of ions.

폴리아크릴산(PAA)의 역삼투특성을 조사하기 위하여, 막지지대로서 셀루로오스아세테이트막 사이에 PAA를 고정시켜 실험을 하였다. 2가동이온은 1가동이온 보다 배제율이 더 높았으며, Donnan배제설에 정성적으로 일치하는 경향을 보였다. 공급액농도의 감소에 따라 1가대 이온고의 배제율은 크게 증가한 반면, 2가대이온고인 경우는 급격한 변화를 보여주지 않았다. PAA막에 의한 고에 대한 배제율은 압력, 공급액농도, 이온가 등에 의존한다는 것을 알았다.