pH-Sensitive Release from Poly(Acrylamide-co-N,N′-Methylene Bisacrylamide) Microspheres
pH-Sensitive Release from Poly(Acrylamide-co-N,N′-Methylene Bisacrylamide) Microspheres
复制标题
聚（丙烯酰胺-co-N,N-亚甲基双丙烯酰胺）微球的 pH 敏感释放
DOI：
10.1252/jcej.28.46
复制
发表时间：
1995
影响因子：
0.8
通讯作者：
Y. Hatate
中科院分区：
文献类型：
--
作者：
H. Yoshizawa;Yasuhiro Mizuma;Y. Uemura;Y. Kawano;Y. Hatate
制备了聚（丙烯酰胺-co-N，N ' -亚甲基双丙烯酰胺）微球，并考察了离子交换对盐酸浓度的影响。实验结果表明，微球对Fe3+的吸附/解吸是通过Fe3+与质子之间的离子交换进行的。当质子浓度低于10-1 mol·dm-3时，微球中Fe3+的释放速度适中。然而，在10-1 mol·dm-3以上，释放速率突然增加。渗透系数与盐酸浓度成正比，在10-1 mol·dm-3左右呈不连续。当盐酸浓度在10-1 mol·dm-3和10-3 mol·dm-3之间变化时，微球具有开关释放机制。渗透系数与搅拌速度无关，缓释活化能为63.9 kJ·mol-1，表明缓释受Fe3+与质子离子交换控制。
Poly(Acrylamide-co-N,N′-methylene bisacrylamide) microspheres were prepared and the sustained release of Fe3+ via ion exchange was investigated in response to the hydrochloric acid concentration. The experimental results revealed that the adsorption/desorption of Fe3+ with microspheres proceeds via ion exchange between Fe3+ and proton. The release rates of Fe3+ from microspheres were found to be moderate under proton concentrations below 10–1 mol·dm–3. However, an abrupt increase in the release rate was observed above 10–1 mol·dm–3. The permeability coefficient was proportional to the hydrochloric acid concentration and had a discontinuity at around 10–1 mol·dm–3. A on-off release mechanism from microspheres was demonstrated in response to a small change in the hydrochloric acid concentration between 10–1 mol·dm–3 and 10–3 mol·dm–3. The permeability coefficients were independent of the stirring speed, and the activation energy for sustained release was 63.9 kJ·mol–1, indicating that sustained release was controlled by ion exchange of Fe3+ and proton.