Fan Yirong, Sun Hui
State Key Laboratory of High-Efficiency Coal Utilization and Green Chemical Engineering, School of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China.
Langmuir. 2024 Mar 19;40(11):5828-5836. doi: 10.1021/acs.langmuir.3c03712. Epub 2024 Mar 8.
The morphological control and transformation of soft nanomaterials are critical for their physical and chemical properties, which can be achieved by dynamically regulating the hydrophilicity of amphiphilic polymers during self-assembly. Herein, an amphiphilic homopolymer poly(-(2,2'-bipyridine)-4-acrylamide) (PBPyAA) with bipyridine pendants is synthesized, and the effect of various parameters including initial concentration, temperature, pH, and metal ion coordination on the self-assembly behavior and morphology of the assemblies is investigated. Upon changing the initial concentration of PBPyAA, bowl-shaped nanoparticles (BNPs) with precisely controlled diameter, opening size, and thickness are obtained. With the decrease of pH of the solution, the negatively charged surface of BNPs transforms to a positively charged state. Furthermore, the addition of divalent metal ions (Co, Mn, and Zn) induces the transformation of BNPs to vesicles and giant vesicles. The effect of the above factors on the morphology of the assemblies is essential to change the hydrophilicity of PBPyAA dynamically, leading to variation of the local viscosity during self-assembly. Overall, manipulation of the structural parameters of BNPs and transformation of BNPs to vesicles are achieved, providing fresh insights for the precise control of the morphologies of soft nanomaterials.
软纳米材料的形态控制和转变对其物理和化学性质至关重要，这可以通过在自组装过程中动态调节两亲聚合物的亲水性来实现。在此，合成了一种带有联吡啶侧基的两亲性均聚物聚（-（2,2'-联吡啶）-4-丙烯酰胺）（PBPyAA），并研究了包括初始浓度、温度、pH值和金属离子配位等各种参数对组装体自组装行为和形态的影响。改变PBPyAA的初始浓度时，可获得直径、开口尺寸和厚度精确可控的碗状纳米颗粒（BNP）。随着溶液pH值的降低，BNP带负电荷的表面转变为带正电荷的状态。此外，添加二价金属离子（Co、Mn和Zn）会促使BNP转变为囊泡和巨型囊泡。上述因素对组装体形态的影响对于动态改变PBPyAA的亲水性至关重要，从而导致自组装过程中局部粘度的变化。总体而言，实现了对BNP结构参数的调控以及BNP向囊泡的转变，为精确控制软纳米材料的形态提供了新的见解。
