Time-resolved SAXS studies on ordering kinetics of block copolymers: Further investigation of two-step ordering from disorder-sphere to hex-cylinder

Sota, Norihiro; Sakamoto, Naoki; Saijo, Kenji; Hashimoto, Takeji

doi:10.1016/j.polymer.2006.03.017

Cited by 14 publications

(18 citation statements)

References 16 publications

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“…The thermoreversible OOT between bcc-spheres and hex-cylinders was experimentally found in a polystyrene- b -polyisoprene diblock copolymer system by Hahimoto et al, sometime after Leibler’s theoretical prediction of thermally induced OOT in linear-type block copolymers . Later studies showed that in the OOT from bcc-spheres to hex-cylinders, the cylinders grew epitaxially along the ⟨111⟩ direction of the bcc lattice. − …”

Section: Introductionmentioning

confidence: 95%

Direct Observation of Faceted Grain Growth of Hexagonal Cylinder Domains in a Side Chain Liquid Crystalline Block Copolymer Matrix

et al. 2013

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Formation of a cylindrical microphase-separated structure (∼20 nm periodicity) of a liquid crystalline block copolymer comprising poly(ethylene oxide) (PEO) and poly(methacrylate) (PMA) bearing azobenzene (Az) mesogens in the side chains was investigated by in situ atomic force microscopy (AFM). The amphiphilic liquid crystalline block copolymer, PEO-b-PMA(Az), forms normally oriented PEO cylinders over the entire film by thermal annealing of various substrates without any pretreatment. Grazing incidence smallangle X-ray scattering (GISAXS) analysis with the simple compensation method of X-ray refraction effect confirmed an order−order transition from a ⟨110⟩-oriented bcc-sphere structure to normally oriented hex-cylinder structure, which is simultaneous liquid crystallization in a cooling process. The growth of cylindrical microphase separation grains in the liquid-crystallization-induced OOT was successfully visualized in the film surface by temperature-controlled AFM. The microphase-separated grains with hexagonally arranged cylinders grow primarily in hexagonal directions layer by layer in a region comprising bcc structures with an average growth rate of 1 nm/s. Moreover, formation of alignment defects of the microphase separation and collision of the grains to form grain boundaries were clearly observed. Furthermore, we succeeded in visualization of anisotropic formation of parallel oriented cylinders. A growth rate along the cylinders was 1−2 nm/s which was much higher than that along a perpendicular direction of the cylinders due to anisotropic growth of liquid crystallization. Such in situ AFM measurements are a significantly powerful tool to afford detailed visual information on structural changes during the formation process of the self-assembled nanostructures.

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Section: Introductionmentioning

confidence: 95%

Direct Observation of Faceted Grain Growth of Hexagonal Cylinder Domains in a Side Chain Liquid Crystalline Block Copolymer Matrix

et al. 2013

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“…The microphase separation structure may be damaged during the flow through the capillary. Since the creation of the microphase was very fast, 37 the above interval was long enough for the microphase separation to be reformed. Hence, what we saw was the reconstructed microstructure.…”

Section: Resultsmentioning

confidence: 99%

Decrease in viscosity of styrene‐isoprene‐styrene filling systems induced by micro elastic phase

Chi

Han

Tian

et al. 2021

J of Applied Polymer Sci

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The melt viscosity of triblock copolymer styrene-isoprene-styrene (SIS) filling systems decreased in some sense by adding 0.1 wt% fillers. The types of fillers included both nano-and non-nano fillers. It was insufficient to explain the phenomenon of viscosity reduction only from the view of nanoscale effects of particles. The results of SAXS and TEM enabled us to relate this behavior to the damage of PS microphase in SIS. The PS microphase acted as a strong entanglement point in the SIS system.When it was damaged, the entanglement among molecular chains weakened greatly, resulting in a decrease in viscosity. The dynamic viscoelasticity (complex viscosity, storage modulus, and loss modulus) of the filling systems was also studied.

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“…Here, time-resolved techniques will be of great importance. Time-resolved SAXS, 97 high-speed atomic force microscopy, 98 and liquid cell TEM 99 are just three examples of promising tools in this space.…”

Section: Characterization Across Time and Spacementioning

confidence: 99%

Where Biology and Traditional Polymers Meet: The Potential of Associating Sequence-Defined Polymers for Materials Science

DeStefano

Segalman

Davidson

2021

JACS Au

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Polymers with precisely defined monomeric sequences present an exquisite tool for controlling material properties by harnessing both the robustness of synthetic polymers and the ability to tailor the inter- and intramolecular interactions so crucial to many biological materials. While polymer scientists traditionally synthesized and studied the physics of long molecules best described by their statistical nature, many biological polymers derive their highly tailored functions from precisely controlled sequences. Therefore, significant effort has been applied toward developing new methods of synthesizing, characterizing, and understanding the physics of non-natural sequence-defined polymers. This perspective considers the synergistic advantages that can be achieved via tailoring both precise sequence control and attributes of traditional polymers in a single system. Here, we focus on the potential of sequence-defined polymers in highly associating systems, with a focus on the unique properties, such as enhanced proton conductivity, that can be attained by incorporating sequence. In particular, we examine these materials as key model systems for studying previously unresolvable questions in polymer physics including the role of chain shape near interfaces and how to tailor compatibilization between dissimilar polymer blocks. Finally, we discuss the critical challenges—in particular, truly scalable synthetic approaches, characterization and modeling tools, and robust control and understanding of assembly pathways—that must be overcome for sequence-defined polymers to attain their potential and achieve ubiquity.

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Time-resolved SAXS studies on ordering kinetics of block copolymers: Further investigation of two-step ordering from disorder-sphere to hex-cylinder

Cited by 14 publications

References 16 publications

Direct Observation of Faceted Grain Growth of Hexagonal Cylinder Domains in a Side Chain Liquid Crystalline Block Copolymer Matrix

Direct Observation of Faceted Grain Growth of Hexagonal Cylinder Domains in a Side Chain Liquid Crystalline Block Copolymer Matrix

Decrease in viscosity of styrene‐isoprene‐styrene filling systems induced by micro elastic phase

Where Biology and Traditional Polymers Meet: The Potential of Associating Sequence-Defined Polymers for Materials Science

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