[Preparation and studies of the adsorbent double cross-linked agar beads entrapped attapulgite clay]

A method for preparing the double cross-linked agar beads entrapped attapulgite clay for hemopurification is reported. Attapulgite clay was coated with agar and cross-linked by epichlorohydrin. After the process of "drying-out", the cross-linked agar beads entrapped attapulgite clay (CAA) was cross-linked again by 10% toluene 2,4,-diisocyanate in acetone at 35 degrees C for 3 h and 30 min. The products withstood autoclaving at 121 degrees C for 30 min. The performance tests showed that the adsorption of the double cross-linked agar beads entrapped attapulgite clay (DCAA) on methylene blue was about 4 times the adsorption of CAA on methylene blue. The intensity of DCAA was raised 6 times, and the appearance of DCAA was denser. Investigation on the blood being in contact with DCAA showed: at 1 h of contact, the loss of leucocyte was <1%, of erythrocyte <5%, and of blood platelets <8%; at 2h of contact, the loss of leucocyte was <2%, of erythrocyte <10%, and of blood platelets <20%.