GUO Meiqiong, HONG Haiyan, SUN Xiaoyi, ZHOU Yongfeng, YAN Deyue. Macroscopic ThreeDimensional Supramoelcular Networks Through the Hierarchical Self-Assembly of Polymer Vesicles. [J]. Acta Polymerica Sinica (4):303-308(2008)
DOI:
GUO Meiqiong, HONG Haiyan, SUN Xiaoyi, ZHOU Yongfeng, YAN Deyue. Macroscopic ThreeDimensional Supramoelcular Networks Through the Hierarchical Self-Assembly of Polymer Vesicles. [J]. Acta Polymerica Sinica (4):303-308(2008) DOI: 10.3724/SP.J.1105.2008.00303.
Macroscopic ThreeDimensional Supramoelcular Networks Through the Hierarchical Self-Assembly of Polymer Vesicles
Synthesis and supramolecular self-assembly of hyperbranched polymers (HBPs) have received more and more attention in recent year
and many delicate supramolecuar structures at all scales and dimensions were generated up to now.However
most of the work reported the one-step self-assembly process from HBPs to supramolecular aggregates.Herein
we report a hierarchical self-assembly of HBPs: the polymer first self-assembled into giant polymer vesicles
and then the vesicles further aggregated into macroscopic surpramolecular network.Two kinds of amphiphilic multiarm copolymers with a same hydrophobic hyperbranched poly[3-ethyl-3-(hydroxymethyl)oxetane] (HBPO) core and different hydrophilic poly(ethylene oxide) (PEO) and poly(2-(dimethylamino)ethyl methacryate) (DMAEMA) arms were synthesized by a “graft from" method.The obtained HBPO-star-PEO can self-assemble in water into giant vesicles
and the HBPO-star-PDMAEMA is pH-responsive and can self-assemble in water into large multimolecular micelles.However
when the two polymers were mixed together
they would co-assemble into pH-responsive giant vesicles around 1~10 μm in water.The self-assembly behavior of the complex vesicle was studied by zeta potential analyzer
laser scanning confocal microscope (LSCM) and optical microscope.The results show that the complex vesicles were electriferous in the solution
and the iso-electric point (IEP) was 8.6
which indicated that PDMAEMA chains were located in the shells of the complex vesicles.At the pH below IEP
the complex vesicles were stable and could be suspended randomly in the solution because of the protonization of PDMAEMA chains.When the solution pH was higher than IEP
the vesicles gradually aggregated together to form the supramolecular structures like pearl necklace and the grape bunch with the increase of pH due to the deprotonation of the vesicles.At an even higher pH
the vesicles aggregated to a threedimensional macroscopic network like a spider web.It is a novel supramolecular structure and belongs to macroscopic molecular self-assembly.The strong cohesion of the individual vesicles is responsible for the formation of such a macroscopic and highly branched vesicle network.It is expected that the present work will give a new light on controlling the hierarchical self-assembly of vesicles and on the preparation of branched and network supramolecular systems.In addition
the supramolecular network can be used as a complex template to direct the self-assembly of some inorganic precursors.