Self-assembly of liquid crystal block copolymer PEG-b-smectic polymer in pure state and in dilute aqueous solution.

A series of amphiphilic LC block copolymers, in which the hydrophobic block is a smectic polymer poly(4-methoxyphenyl 4-(6-acryloyloxy-hexyloxy)-benzoate) (PA6esterl) and the hydrophilic block is polyethyleneglycol (PEG), were synthesized and characterized. The self-assembly of one of them in both the pure state and the dilute aqueous solution was investigated in detail. Nano-structures in the pure state were studied by SAXS and WAXS on samples aligned by a magnetic field. A hexagonal cylindrical micro-segregation phase was observed with a lattice distance of 11.2 nm. The PEG blocks are in the cylinder, while the smectic polymer blocks form a matrix with layer spacing 2.4 nm and layer normal parallel to the long axis of the cylinders. Faceted unilamellar polymer vesicles, polymersomes, were formed in water, as revealed by cryo-TEM. In the lyotropic bilayer membrane of these polymersomes, the thermotropic smectic order in the hydrophobic block is clearly visible with layer normal parallel to the membrane surface.

[1]  C. Tanford.  Macromolecules , 1994, Nature.

[2]  L. Leibler.  Theory of Microphase Separation in Block Copolymers , 1980 .

[3]  H. Ringsdorf,et al.  Synthesis and phase behaviour of liquid crystalline polyacrylates , 1982 .

[4]  F. Bates,et al.  Polymer-Polymer Phase Behavior , 1991, Science.

[5]  H. Fischer,et al.  On the Influence of the Morphological Structure on the Liquid Crystalline Behavior of Liquid Crystalline Side Chain Block Copolymers , 1994 .

[6]  A. Levelut,et al.  The Measurement of the Nematic Order Parameter by X-ray Scattering Reconsidered , 1995 .

[7]  K. Edwards,et al.  Effect of bilayer phase transitions on vesicle structure and its influence on the kinetics of viologen reduction. , 1995 .

[8]  E. Thomas,et al.  Impact of Morphological Orientation in Determining Mechanical Properties in Triblock Copolymer Systems , 1996 .

[9]  H. Jaeger,et al.  Local Control of Microdomain Orientation in Diblock Copolymer Thin Films with Electric Fields , 1996, Science.

[10]  Glenn H. Fredrickson,et al.  Dynamics of Block Copolymers: Theory and Experiment , 1996 .

[11]  Ian W. Hamley,et al.  The physics of block copolymers , 1998 .

[12]  Yoshinori Funaki,et al.  Single-Grain Lamellar Microdomain from a Diblock Copolymer , 1999 .

[13]  Paschalis Alexandridis,et al.  Amphiphilic Block Copolymers: Self-Assembly and Applications , 2000 .

[14]  K. Guarini,et al.  Ultrahigh-density nanowire arrays grown in self-assembled diblock copolymer templates. , 2000, Science.

[15]  Edwin L. Thomas,et al.  Microdomain patterns from directional eutectic solidification and epitaxy , 2000, Nature.

[16]  E. Thomas,et al.  Perpendicular Deformation of a Near-Single-Crystal Triblock Copolymer with a Cylindrical Morphology. 1. Synchrotron SAXS , 2000 .

[17]  C. Tondre,et al.  Vesicle-Forming Properties of New Phospholipid Analogues Derived from N-Phosphonoacetyl-l-aspartate (PALA): Particle Features and Morphology in Relation with Alkyl Chain Lengths† , 2001 .

[18]  Thomas Zemb,et al.  Self-assembly of regular hollow icosahedra in salt-free catanionic solutions , 2001, Nature.

[19]  E. Kramer,et al.  Graphoepitaxy of Spherical Domain Block Copolymer Films , 2001 .

[20]  Henry I. Smith,et al.  Fabrication of nanostructures with long-range order using block copolymer lithography , 2002 .

[21]  P. Keller,et al.  Novel Liquid Crystalline Block Copolymers by ATRP and ROMP , 2003 .

[22]  P. Nealey,et al.  Epitaxial self-assembly of block copolymers on lithographically defined nanopatterned substrates , 2003, Nature.

[23]  P. Keller,et al.  An Artificial Muscle with Lamellar Structure Based on a Nematic Triblock Copolymer , 2004 .

[24]  E. Thomas,et al.  Alignment of Self-Assembled Hierarchical Microstructure in Liquid Crystalline Diblock Copolymers Using High Magnetic Fields , 2004 .

[25]  Joy Y. Cheng,et al.  Nanostructure engineering by templated self-assembly of block copolymers , 2004, Nature materials.

[26]  P. Van der Meeren,et al.  Temperature quenched DODAB dispersions: fluid and solid state coexistence and complex formation with oppositely charged surfactant. , 2004, Langmuir : the ACS journal of surfaces and colloids.

[27]  Ting Xu,et al.  Highly Oriented and Ordered Arrays from Block Copolymers via Solvent Evaporation , 2004 .

[28]  J. Zimmerberg,et al.  Shape control through molecular segregation in giant surfactant aggregates. , 2004, Proceedings of the National Academy of Sciences of the United States of America.

[29]  Ian W. Hamley,et al.  Interplay between Smectic Ordering and Microphase Separation in a Series of Side-Group Liquid-Crystal Block Copolymers , 2004 .

[30]  Matthias F. Schneider,et al.  Balance of pH and Ionic Strength Influences on Chain Melting Transition in Catanionic Vesicles , 2004 .

[31]  Stephen Y. Chou,et al.  Macroscopic Orientation of Block Copolymer Cylinders in Single‐Layer Films by Shearing , 2004 .

[32]  宁北芳,et al.  疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A , 2005 .

[33]  Richard A. Register,et al.  Shear‐Induced Alignment in Thin Films of Spherical Nanodomains , 2005 .

[34]  I. Hamley.  Block Copolymers in Solution: Fundamentals and Applications , 2005 .

[35]  P. Keller,et al.  Polymer vesicles formed by amphiphilic diblock copolymers containing a thermotropic liquid crystalline polymer block. , 2005, Chemical communications.

[36]  R. Piñol,et al.  Formation of polymer vesicles by liquid crystal amphiphilic block copolymers. , 2006, Langmuir : the ACS journal of surfaces and colloids.

[37]  Kazuhito Watanabe,et al.  Optical Alignment and Patterning of Nanoscale Microdomains in a Block Copolymer Thin Film , 2006 .

[38]  Guojun Liu,et al.  Block copolymers in nanoscience , 2006 .

[39]  Haifeng Yu,et al.  Photoinduced alignment of nanocylinders by supramolecular cooperative motions. , 2006, Journal of the American Chemical Society.

[40]  Bradley D Olsen,et al.  Hierarchical nanostructure control in rod-coil block copolymers with magnetic fields. , 2007, Nano letters.

[41]  Eric Verploegen,et al.  Observation of Transverse Cylinder Morphology in Side Chain Liquid Crystalline Block Copolymers , 2007 .

[42]  C. van Nostrum,et al.  Triggered destabilisation of polymeric micelles and vesicles by changing polymers polarity: an attractive tool for drug delivery. , 2007, Journal of Controlled Release.

[43]  B. Lindman,et al.  Mechanisms behind the faceting of catanionic vesicles by polycations: chain crystallization and segregation. , 2007, The journal of physical chemistry. B.

[44]  Patrick Keller,et al.  Self-assembly of PEG-b-liquid crystal polymer : The role of smectic order in the formation of nanofibers , 2007 .

[45]  Patrick Keller,et al.  Stimuli-responsive polymer vesicles , 2009 .

[46]  F. Brochard-Wyart,et al.  Bursting of sensitive polymersomes induced by curling , 2009, Proceedings of the National Academy of Sciences.

[47]  R. Rosenfeld.  Nature , 2009, Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery.