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Wei-Na He

Bio: Wei-Na He is an academic researcher from Zhejiang University. The author has contributed to research in topics: Crystallization. The author has an hindex of 1, co-authored 1 publications receiving 291 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, the self-assembly of block copolymers (BCPs) in the presence of crystallization is reviewed, for BCPs in the bulk, thin films, single crystals and micelles.

320 citations


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01 Mar 1996
TL;DR: In this paper, a mean-field phase diagram for conformationally symmetric diblock melts using the standard Gaussian polymer model is presented, which traverses the weak- to strong-segregation regimes, is free of traditional approximations.
Abstract: A mean-field phase diagram for conformationally symmetric diblock melts using the standard Gaussian polymer model is presented. Our calculation, which traverses the weak- to strong-segregation regimes, is free of traditional approximations. Regions of stability are determined for disordered (DIS) melts and for ordered structures including lamellae (L), hexagonally packed cylinders (H), body-centered cubic spheres (QIm3m), close-packed spheres (CPS), and the bicontinuous cubic network with Ia3d symmetry (QIa3d). The CPS phase exists in narrow regions along the order−disorder transition for χN ≥ 17.67. Results suggest that the QIa3d phase is not stable above χN ∼ 60. Along the L/QIa3d phase boundaries, a hexagonally perforated lamellar (HPL) phase is found to be nearly stable. Our results for the bicontinuous Pn3m cubic (QPn3m) phase, known as the OBDD, indicate that it is an unstable structure in diblock melts. Earlier approximation schemes used to examine mean-field behavior are reviewed, and compa...

1,256 citations

Journal ArticleDOI
TL;DR: Using a series of platelet-forming block copolymers, the living crystallization-driven self-assembly (CDSA) approach can be extended to growth in 2D and used to prepare uniform lenticular platelet micelles of controlled size and to construct precisely concentric lenticular micells composed of spatially distinct functional regions.
Abstract: Self-assembly is commonly used to construct complex nanostructures from soft matter. Now, using the living crystallization-driven self-assembly approach, controlled nanostructure growth in both one and two dimensions has been achieved. Uniform lenticular multiblock platelets, as well as hierarchical structures analogous to nanoscale single- and double-headed arrows and spears have been prepared with controlled sizes in two dimensions.

296 citations

Journal ArticleDOI
TL;DR: In this article, the authors outline recent advances concerning the formation and potential uses of block copolymer micelles, a class of soft-matter-based nanoparticles of growing importance, in terms of morphological diversity, structural complexity, control over micelle dimensions, scale-up, and applications in a range of areas from nanocomposites to nanomedicine.
Abstract: This Perspective outlines recent advances concerning the formation and potential uses of block copolymer micelles, a class of soft-matter-based nanoparticles of growing importance. As a result of rapidly expanding interest since the mid-1990s, substantial advances have been reported in terms of the development of morphological diversity, structural complexity, control over micelle dimensions, scale-up, and applications in a range of areas from nanocomposites to nanomedicine.

279 citations

Journal ArticleDOI
TL;DR: In this paper, a change in nucleation mechanism, from heterogeneous nucleation to surface nucleation (or in extreme cases, homogeneous nucleations), was proposed, which reflected that nucleation is the rate determining step in the overall crystallization of ideally confined polymers.

257 citations

Journal Article
TL;DR: In this article, the solution-state assembly of all-conjugated polythiophene diblock copolymers containing nonpolar (hexyl) and polar (triethylene glycol) side chains is described.
Abstract: We report on the solution-state assembly of all-conjugated polythiophene diblock copolymers containing nonpolar (hexyl) and polar (triethylene glycol) side chains. The polar substituents provide a large contrast in solubility, enabling formation of stably suspended crystalline fibrils even under very poor solvent conditions for the poly(3-hexylthiophene) block. For appropriate block ratios, complexation of the triethylene glycol side chains with added potassium ions drives the formation of helical nanowires that further bundle into superhelical structures.

191 citations