Influence of block lengths and symmetries of block copolymers on phase behavior of polymer A/polymer B/block copolymer ternary blends

Dai, Bing; Song, Mo; Hourston, D. J.; He, Xuehao; Liang, Haojun; Pan, Chen

doi:10.1016/j.polymer.2003.12.010

Cited by 10 publications

(6 citation statements)

References 22 publications

(11 reference statements)

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“…Two theories could be proposed to explain this observation: hydrogen bonds between pHEMA chains may have inhibited phase separation or very short PDMS blocks (1400 g mol À1 ) bridged between long end pHEMA blocks, slowing the phase separation. 37 The morphology of H92S8 could be explained in similar fashions based on the SAXS profile. In this copolymer, the ordered structure was disrupted due to asymmetry between the pHEMA and PDMS blocks, which led to a high intensity primary reflection and a weak and broad shoulder at higher q.…”

Section: Afm Analysismentioning

confidence: 85%

Synthesis, characterization and properties of amphiphilic block copolymers of 2-hydroxyethyl methacrylate and polydimethylsiloxane prepared by atom transfer radical polymerization

Bas

Soucek

2012

Polym J

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A series of amphiphilic poly(2-hydroxyethyl methacrylate)-b-polydimethylsiloxane-b-poly(2-hydroxyethyl methacrylate) (pHEMAb-PDMS-b-pHEMA) (A-B-A) triblock copolymers were synthesized with varying block molecular weights. Control over the polymerization, micellar size and size distribution, dynamic mechanical properties, and film morphology of nine triblock copolymers was investigated as a function of block length. The polymerization resulted in copolymers with polydispersity index below 1.5. The self-assembly behavior of the triblock copolymers was studied in selective solvents for A and B blocks. The micellar diameter was determined by dynamic light scattering and transmission electron microscopy. The film morphologies were investigated by small angle X-ray scattering. Phase separation was observed when the blocks had similar molecular weights (symmetry). However, the ordering of the morphology was disrupted when the blocks lengths were asymmetric. Phase separation was observed by atomic force microscopy when the block molecular weights were symmetric. The viscoelastic properties were examined using dynamic mechanical analysis. The modulus and crosslink density increased with increasing pHEMA content.

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Section: Afm Analysismentioning

confidence: 85%

Synthesis, characterization and properties of amphiphilic block copolymers of 2-hydroxyethyl methacrylate and polydimethylsiloxane prepared by atom transfer radical polymerization

Bas

Soucek

2012

Polym J

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“…A number of researchers have considered the effect of copolymers on the demixing transition for different copolymer architectures. 256,302,303 Dadmun and Waldow 256 have pointed out that copolymers not only shift the transition point towards higher values of the Flory-Huggins parameter χ, but also change the critical exponents via a Fisherrenormalization mechanism. In the phase-segregated regime, copolymers aggregate to the interface, reduce the interfacial tension, and enlarge the interfacial width.…”

Section: Copolymers As Compatibilizersmentioning

confidence: 99%

Theory and Simulation of Multiphase Polymer Systems

Schmid

2011

Handbook of Multiphase Polymer Systems

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The theory of multiphase polymer systems has a venerable tradition. The 'classical' theory of polymer demixing, the Flory-Huggins theory, was developed in the 1940s [1,2]. It is still the starting point for most current approaches -be they improved theories for polymer (im)miscibility that take into account the microscopic structure of blends more accurately, or sophisticated field theories that allow to study inhomogeneous multicomponent systems of polymers with arbitrary architectures in arbitrary geometries. In contrast, simulations of multiphase polymer systems are quite young. They are still limited by the fact that one must simulate a large number of large molecules in order to obtain meaningful results. Both powerful computers and smart modeling and simulation approaches are necessary to overcome this problem.In the limited space of this chapter, we can only give a taste of the state-of-the-art in both areas, theory and simulation. Since the theory has reached a fairly mature stage by now, many aspects of it are covered in textbooks on polymer physics [3][4][5][6][7][8][9]. The information on the state-of-the art of simulations is much more scattered. This is why we have put some effort into putting together a representative list of references in this area -which is of course still far from complete.The chapter is organized as follows. In Section II, we briefly introduce some basic concepts of polymer theory. The purpose of this part is to make the chapter accessible to readers who are not very familiar with polymer physics; it can safely be skipped by the others. Section III is devoted to the theory of multiphase polymer systems. We recapitulate the Flory-Huggins theory and introduce in particular the concept of the Flory interaction parameter (the χ parameter), which is a central ingredient in most theoretical descriptions of multicomponent polymer systems. Then we focus on one of the most successful mean-field theories for inhomogeneous (co)polymer blends, the self-consistent field theory. We sketch the main idea, discuss various Handbook of Multiphase Polymer Systems, First Edition. Edited by Abderrahim Boudenne, Laurent Ibos, Yves Candau, and Sabu Thomas.

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“…Recently, devices created from nanopatterning, have usually been prepared within lithographically-defined templates, and have been paid great attention because of high effiency and low-cost. Up to now, several methods, such as phase separation 5 , laser deposition 1 , spin-coating 3 , atomic force microscopy (AFM) oxidation or selective wet etching 2 have been used to design micro-/nano-patternings of polymers or semiconductors. But the fussy processes and requirement of special equipment make them unsuitable for wide applications.…”

Section: Introductionmentioning

confidence: 99%

Nanoflake Patterning of Self-Assembled Multilayer Films

Tang

Chu

2013

Polymers and Polymer Composites

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Nanopatterning has attracted much attention because of its growing use in designing nanoelectronic and optoelectronic devices. Development of a facile route to nanopatterning is a persistent goal in nanotechnology. Originating from positively charged polyethyleneimine (PEI) and negatively charged poly(4-styrenesulfonate) (PSS), we successfully designed separable nanoflake patterning using layer-by-layer self-assembly technique by sequential adsorption of PEI and PSS. The morphology and size of the nanopatterning can be controlled by adjusting the number of bilayers in the film. Electrochemical measurements reveal that the (PEI/PSS) nanoflakes have good electroactivity and permeability for the electrolytes undergoing redox reaction. By controlling the distribution of surface charges on substrates, nanopatterning can be facilely achieved by self-assembly method.

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Influence of block lengths and symmetries of block copolymers on phase behavior of polymer A/polymer B/block copolymer ternary blends

Cited by 10 publications

References 22 publications

Synthesis, characterization and properties of amphiphilic block copolymers of 2-hydroxyethyl methacrylate and polydimethylsiloxane prepared by atom transfer radical polymerization

Synthesis, characterization and properties of amphiphilic block copolymers of 2-hydroxyethyl methacrylate and polydimethylsiloxane prepared by atom transfer radical polymerization

Theory and Simulation of Multiphase Polymer Systems

Nanoflake Patterning of Self-Assembled Multilayer Films

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