The crystallization of barium oxalate in the presence of a double-hydrophilic block copolymer poly(ethylene glycol)-block-poly(methacrylic acid) (PEG-b-PMAA) was investigated. Barium oxalate crystals with a complex fo...The crystallization of barium oxalate in the presence of a double-hydrophilic block copolymer poly(ethylene glycol)-block-poly(methacrylic acid) (PEG-b-PMAA) was investigated. Barium oxalate crystals with a complex form, such as fan-like aggregates consisting of rod-like BaC 2O 4·H 2O crystals and spherical aggregates consisting of flake-like BaC 2O 4·3.5H 2O crystals were readily produced in aqueous solutions of PEG-b-PMMA. This result may provide an effective method for controlling the morphology and polymorph of inorganic crystals.展开更多
The crystallization of calcite from mixed alcohol water solvents in the presence of a double hydrophilic block copolymer poly(ethylene glycol) block poly(methacrylic acid)(PEG b PMAA) has been investigated. It was rev...The crystallization of calcite from mixed alcohol water solvents in the presence of a double hydrophilic block copolymer poly(ethylene glycol) block poly(methacrylic acid)(PEG b PMAA) has been investigated. It was revealed that with increasing the volume fractions of ethanol or isopropanol, the morphology of the CaCO 3 particles generally varies from peanuts through rods to spheres in the presence of the polymer. Specifically, uniform rounded calcite rods, which are about 2 μm in length with an aspect ratio of 2.6, were obtained in the isopropanol solution with volume fraction 50%.展开更多
通过可逆加成断裂链转移聚合(RAFT)成功制备了聚苯乙烯-聚4-乙烯基吡啶(PS-b-P4VP)双亲性嵌段共聚物。利用核磁共振氢谱(1 H NMR)对产物的结构进行了表征。然后研究了聚合物在选择性溶剂中的自组装行为,测试表明该聚合物在一定条件下可...通过可逆加成断裂链转移聚合(RAFT)成功制备了聚苯乙烯-聚4-乙烯基吡啶(PS-b-P4VP)双亲性嵌段共聚物。利用核磁共振氢谱(1 H NMR)对产物的结构进行了表征。然后研究了聚合物在选择性溶剂中的自组装行为,测试表明该聚合物在一定条件下可自组装形成囊泡状,以此结构作为原位反应器成功包覆纳米银制备了亚微米级的纳米复合材料,应用紫外-可见吸收光谱(UV-Vis)、X射线衍射(XRD)、扫描电镜(SEM)和X射线能谱仪(EDS)等测试手段对复合结果进行了表征。展开更多
以PEO-Br为大分子引发剂,通过ATRP法合成了一组两亲性两嵌段共聚物PEO45-bPtBAx(x=28,35,53).采用HNMR、FTIR、SEC和TEM对产物进行了表征,讨论了投料比对控制产物的分子链结构,分子量及其分布的影响.结果表明,tBA的转化率较高,1 H NMR...以PEO-Br为大分子引发剂,通过ATRP法合成了一组两亲性两嵌段共聚物PEO45-bPtBAx(x=28,35,53).采用HNMR、FTIR、SEC和TEM对产物进行了表征,讨论了投料比对控制产物的分子链结构,分子量及其分布的影响.结果表明,tBA的转化率较高,1 H NMR结果显示成功制得目标产物,所得嵌段共聚物均具有极窄的分子量分布(Mw/Mn≤1.07).在tBA相对于PEO-Br的投料比较小时可以对嵌段共聚物结构进行精确调控.tBA投入量的增大会导致分子量分布变宽及引发效率下降.PEO45-b-PtBA35被成功水解为PEO45-b-PAA35,在中性水溶液中PEO45-b-PAA35自组装形成了分散较为均匀的球形胶束.展开更多
文摘The crystallization of barium oxalate in the presence of a double-hydrophilic block copolymer poly(ethylene glycol)-block-poly(methacrylic acid) (PEG-b-PMAA) was investigated. Barium oxalate crystals with a complex form, such as fan-like aggregates consisting of rod-like BaC 2O 4·H 2O crystals and spherical aggregates consisting of flake-like BaC 2O 4·3.5H 2O crystals were readily produced in aqueous solutions of PEG-b-PMMA. This result may provide an effective method for controlling the morphology and polymorph of inorganic crystals.
文摘The crystallization of calcite from mixed alcohol water solvents in the presence of a double hydrophilic block copolymer poly(ethylene glycol) block poly(methacrylic acid)(PEG b PMAA) has been investigated. It was revealed that with increasing the volume fractions of ethanol or isopropanol, the morphology of the CaCO 3 particles generally varies from peanuts through rods to spheres in the presence of the polymer. Specifically, uniform rounded calcite rods, which are about 2 μm in length with an aspect ratio of 2.6, were obtained in the isopropanol solution with volume fraction 50%.
文摘通过可逆加成断裂链转移聚合(RAFT)成功制备了聚苯乙烯-聚4-乙烯基吡啶(PS-b-P4VP)双亲性嵌段共聚物。利用核磁共振氢谱(1 H NMR)对产物的结构进行了表征。然后研究了聚合物在选择性溶剂中的自组装行为,测试表明该聚合物在一定条件下可自组装形成囊泡状,以此结构作为原位反应器成功包覆纳米银制备了亚微米级的纳米复合材料,应用紫外-可见吸收光谱(UV-Vis)、X射线衍射(XRD)、扫描电镜(SEM)和X射线能谱仪(EDS)等测试手段对复合结果进行了表征。
文摘以PEO-Br为大分子引发剂,通过ATRP法合成了一组两亲性两嵌段共聚物PEO45-bPtBAx(x=28,35,53).采用HNMR、FTIR、SEC和TEM对产物进行了表征,讨论了投料比对控制产物的分子链结构,分子量及其分布的影响.结果表明,tBA的转化率较高,1 H NMR结果显示成功制得目标产物,所得嵌段共聚物均具有极窄的分子量分布(Mw/Mn≤1.07).在tBA相对于PEO-Br的投料比较小时可以对嵌段共聚物结构进行精确调控.tBA投入量的增大会导致分子量分布变宽及引发效率下降.PEO45-b-PtBA35被成功水解为PEO45-b-PAA35,在中性水溶液中PEO45-b-PAA35自组装形成了分散较为均匀的球形胶束.
