Core-shell structured SiO2/poly（N-isopropylacrylamide） （SiO2/PNIPAM） microspheres were successfully fabricated through hydrolysis and condensation reaction of tertraethyl orthosilicate （TEOS） on the surface of P...Core-shell structured SiO2/poly（N-isopropylacrylamide） （SiO2/PNIPAM） microspheres were successfully fabricated through hydrolysis and condensation reaction of tertraethyl orthosilicate （TEOS） on the surface of PNIPAM template at 50 ~C. The PNIPAM template can be easily removed by water at room temperature so that SiO2 hollow microspheres were finally obtained. The transmission electron microscope and scanning electron microscope observations indicated that SiO2 hollow microspheres with an average diameter of 150 nm can be formed only if there are enough concentration of PNIPAM and TEOS, and the hy- drolysis time of TEOS. FTIR analysis showed that part of PNIPAM remained on the wall of SiO2 because of the strong interaction between PNIPAM and silica. This work provides a clean and efficient way to prepare hollow microspheres.展开更多
The abzyme with deiodinase activity was modified with diethyl pyrocarbonate(DEPC) and carbodiimide(EDC) respectively. The modified abzymes were dialyzed and their activities were compared with that of the native abzym...The abzyme with deiodinase activity was modified with diethyl pyrocarbonate(DEPC) and carbodiimide(EDC) respectively. The modified abzymes were dialyzed and their activities were compared with that of the native abzyme. The results indicate that the histidine residue is one of the essential groups in the abzyme, and the modification causes the catalytic activity a loss of 70%. The modification of the residues containing carboxyl group with EDC leads to a loss of 50% activity, indicating that acid amino residues play important roles in the catalytic reaction.展开更多
文摘Core-shell structured SiO2/poly（N-isopropylacrylamide） （SiO2/PNIPAM） microspheres were successfully fabricated through hydrolysis and condensation reaction of tertraethyl orthosilicate （TEOS） on the surface of PNIPAM template at 50 ~C. The PNIPAM template can be easily removed by water at room temperature so that SiO2 hollow microspheres were finally obtained. The transmission electron microscope and scanning electron microscope observations indicated that SiO2 hollow microspheres with an average diameter of 150 nm can be formed only if there are enough concentration of PNIPAM and TEOS, and the hy- drolysis time of TEOS. FTIR analysis showed that part of PNIPAM remained on the wall of SiO2 because of the strong interaction between PNIPAM and silica. This work provides a clean and efficient way to prepare hollow microspheres.
文摘The abzyme with deiodinase activity was modified with diethyl pyrocarbonate(DEPC) and carbodiimide(EDC) respectively. The modified abzymes were dialyzed and their activities were compared with that of the native abzyme. The results indicate that the histidine residue is one of the essential groups in the abzyme, and the modification causes the catalytic activity a loss of 70%. The modification of the residues containing carboxyl group with EDC leads to a loss of 50% activity, indicating that acid amino residues play important roles in the catalytic reaction.
