Synthesis of bottlebrush block copolymers from bottlebrush polystyrene and bottlebrush random copolymer of ω ‐end‐norbornyl polymethacrylates and their self‐assembly

2020 ◽  
Vol 58 (16) ◽  
pp. 2159-2167 ◽  
Author(s):  
Ho‐Bin Seo ◽  
Myung‐Jin Kim ◽  
Yong‐Guen Yu ◽  
Chang‐Geun Chae ◽  
Jae‐Suk Lee
Soft Matter ◽  
2015 ◽  
Vol 11 (47) ◽  
pp. 9107-9114 ◽  
Author(s):  
Gunja Pandav ◽  
William J. Durand ◽  
Christopher J. Ellison ◽  
C. Grant Willson ◽  
Venkat Ganesan

Directed self-assembly of block copolymers on chemical patterns with sidewall guiding lines is examined as a function of backfill brush properties, block copolymer film thickness, pattern size, and sidewall interaction strength.


2002 ◽  
Vol 724 ◽  
Author(s):  
Elizabeth R. Wright ◽  
R. Andrew McMillan ◽  
Alan Cooper ◽  
Robert P. Apkarian ◽  
Vincent P. Conticello

AbstractTriblock copolymers have traditionally been synthesized with conventional organic components. However, triblock copolymers could be synthesized by the incorporation of two incompatible protein-based polymers. The polypeptides would differ in their hydrophobicity and confer unique physiochemical properties to the resultant materials. One protein-based polymer, based on a sequence of native elastin, that has been utilized in the synthesis of biomaterials is poly (Valine-Proline-Glycine-ValineGlycine) or poly(VPGVG) [1]. This polypeptide has been shown to have an inverse temperature transition that can be adjusted by non-conservative amino acid substitutions in the fourth position [2]. By combining polypeptide blocks with different inverse temperature transition values due to hydrophobicity differences, we expect to produce amphiphilic polypeptides capable of self-assembly into hydrogels. Our research examines the design, synthesis and characterization of elastin-mimetic block copolymers as functional biomaterials. The methods that are used for the characterization include variable temperature 1D and 2D High-Resolution-NMR, cryo-High Resolutions Scanning Electron Microscopy and Differential Scanning Calorimetry.


Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4705
Author(s):  
Boer Liu ◽  
Xi Chen ◽  
Glenn A. Spiering ◽  
Robert B. Moore ◽  
Timothy E. Long

This work reveals the influence of pendant hydrogen bonding strength and distribution on self-assembly and the resulting thermomechanical properties of A-AB-A triblock copolymers. Reversible addition-fragmentation chain transfer polymerization afforded a library of A-AB-A acrylic triblock copolymers, wherein the A unit contained cytosine acrylate (CyA) or post-functionalized ureido cytosine acrylate (UCyA) and the B unit consisted of n-butyl acrylate (nBA). Differential scanning calorimetry revealed two glass transition temperatures, suggesting microphase-separation in the A-AB-A triblock copolymers. Thermomechanical and morphological analysis revealed the effects of hydrogen bonding distribution and strength on the self-assembly and microphase-separated morphology. Dynamic mechanical analysis showed multiple tan delta (δ) transitions that correlated to chain relaxation and hydrogen bonding dissociation, further confirming the microphase-separated structure. In addition, UCyA triblock copolymers possessed an extended modulus plateau versus temperature compared to the CyA analogs due to the stronger association of quadruple hydrogen bonding. CyA triblock copolymers exhibited a cylindrical microphase-separated morphology according to small-angle X-ray scattering. In contrast, UCyA triblock copolymers lacked long-range ordering due to hydrogen bonding induced phase mixing. The incorporation of UCyA into the soft central block resulted in improved tensile strength, extensibility, and toughness compared to the AB random copolymer and A-B-A triblock copolymer comparisons. This study provides insight into the structure-property relationships of A-AB-A supramolecular triblock copolymers that result from tunable association strengths.


Author(s):  
Weihua Li ◽  
Xueying Gu

Since tremendous progress has been made, directed self-assembly (DSA) of block copolymers has been regarded as one of the most promising bottom-up lithography techniques. In particular, DSA has been successfully...


2020 ◽  
Vol 2 (11) ◽  
pp. 4893-4901
Author(s):  
Karthika Madathil ◽  
Kayla A. Lantz ◽  
Morgan Stefik ◽  
Gila E. Stein

2021 ◽  
Author(s):  
Wei Wen ◽  
Aihua Chen

Self-assembly of amphiphilic single chain Janus nanoparticles (SCJNPs) is a novel and promising approach to fabricate assemblies with diversified morphologies. However, the experimental research of the self-assembly behavior of SCJNPs...


Soft Matter ◽  
2021 ◽  
Author(s):  
Alexander Kantardjiev

We carried out a series of coarse-grained molecular dynamics liposome-copolymer simulations with varying extent of copolymer concentration in an attempt to understand the effect of copolymer structure and concentration on vesicle self-assembly and stability.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1412
Author(s):  
Eunkyung Ji ◽  
Cian Cummins ◽  
Guillaume Fleury

The ability of bottlebrush block copolymers (BBCPs) to self-assemble into ordered large periodic structures could greatly expand the scope of photonic and membrane technologies. In this paper, we describe a two-step synthesis of poly(l-lactide)-b-polystyrene (PLLA-b-PS) BBCPs and their rapid thin-film self-assembly. PLLA chains were grown from exo-5-norbornene-2-methanol via ring-opening polymerization (ROP) of l-lactide to produce norbornene-terminated PLLA. Norbonene-terminated PS was prepared using anionic polymerization followed by a termination reaction with exo-5-norbornene-2-carbonyl chloride. PLLA-b-PS BBCPs were prepared from these two norbornenyl macromonomers by a one-pot sequential ring opening metathesis polymerization (ROMP). PLLA-b-PS BBCPs thin-films exhibited cylindrical and lamellar morphologies depending on the relative block volume fractions, with domain sizes of 46–58 nm and periodicities of 70–102 nm. Additionally, nanoporous templates were produced by the selective etching of PLLA blocks from ordered structures. The findings described in this work provide further insight into the controlled synthesis of BBCPs leading to various possible morphologies for applications requiring large periodicities. Moreover, the rapid thin film patterning strategy demonstrated (>5 min) highlights the advantages of using PLLA-b-PS BBCP materials beyond their linear BCP analogues in terms of both dimensions achievable and reduced processing time.


2010 ◽  
Vol 28 (2) ◽  
pp. 84-92 ◽  
Author(s):  
Jieshu Qian ◽  
Meng Zhang ◽  
Ian Manners ◽  
Mitchell A. Winnik

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