Effect of polyampholyte net charge on complex coacervation between polyampholytes and inorganic polyoxometalate giant anions
Effect of polyampholyte net charge on complex coacervation between polyampholytes and inorganic polyoxometalate giant anions
复制标题
DOI：
10.1039/d0sm01565b
复制
发表时间：
2020-12-07
期刊：
影响因子：
3.4
通讯作者：
Zhu, Yingxi
中科院分区：
文献类型：
--
作者：
Ferreira, Manuela;Jing, Benxin;Zhu, Yingxi
用带正电和负电单体的两性聚合物共聚物，研究了两性离子聚合物的净电荷对杂化聚两性聚合物-多金属氧酸盐（POM）配合物的相行为和粘弹性的影响。通过改变带负电荷的2-丙烯酰胺-2-甲基-1-丙磺酸（AMPS）与带正电荷的[3-（甲基丙烯酰胺）丙基]三甲基氯化铵（MAPTAC）单体在水溶液中的投料摩尔比，合成了具有不同净电荷的两性离子多两性电解质，简称PA(x)M(y)。在添加LiCl的水溶液中，增加带正电的MAPTAC单体的摩尔分数和LiCl浓度，可以促进PA(x)M(y)与无机阴离子偏渗态POM （{W-12}）之间的凝聚形成。盐展宽的凝聚作用明显不同于相反电荷的聚电解质之间的盐抑制凝聚作用，表明PA(x)M(y)-{W-12}的两性离子-阴离子配对是由于多价{W-12}巨离子与PA(x)M(y)的结合比简单离子更强。重要的是，当多两性聚合物中的AMPS或MAPTAC单体分数与有效净中性情况相比仅变化+/- 5%时，PA(x)M(y)-{W-12}凝聚体的粘弹性可以被修改4-5倍，这为精细控制仿生复合凝聚体的宏观离子相互作用和材料性能提供了新的调节参数。
The effect of net charge of zwitterionic polymers on the phase behavior and viscoelastic properties of hybrid polyampholyte-polyoxometalate (POM) complexes in salted aqueous solutions is investigated with polyampholyte copolymers consisting of both positively and negatively charged monomers. Zwitterionic polyampholytes of varied net charge, abbreviated as PA(x)M(y), are synthesized by varying the feeding molar ratio of negatively charged 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) to positively charged [3-(methacryloylamino)propyl]trimethylammonium chloride (MAPTAC) monomers in aqueous solution. The coacervate formation between PA(x)M(y) and inorganic anionic metatungstate POM ({W-12}) in LiCl added aqueous solutions can be enhanced by increasing the molar fraction of positively charged MAPTAC monomer and LiCl concentration. The salt-broadened coacervation, clearly distinct from the salt-suppressed one between oppositely charged polyelectrolytes, suggests the account of zwitterion-anion pairing for PA(x)M(y)-{W-12} coacervate formation due to stronger binding of multivalent {W-12} giant ions with PA(x)M(y) than simple ions. Importantly, as AMPS or MAPTAC monomer fraction in polyampholytes is varied by merely +/- 5% from the effective net neutral case, the viscoelasticity of PA(x)M(y)-{W-12} coacervates can be modified by 4-5 folds, suggesting a new tuning parameter to fine control the macroionic interactions and material properties of biomimetic complex coacervates.