Publisher：Proceedings of the National Academy of Sciences of the United States of America  

Liquid–liquid phase separation, whereby two liquids spontaneously demix, is ubiquitous in industrial, environmental, and biological processes. While isotropic fluids are known to condense into spherical droplets in the binodal region, these dynamics are poorly understood for structured fluids. Here, we report the unique observation of condensate networks, which spontaneously assemble during the demixing of a mesogen from a solvent. Condensing mesogens form rapidly elongating filaments, rather than spheres, to relieve distortion of an internal smectic mesophase. As filaments densify, they collapse into bulged discs, lowering the elastic free energy. Additional distortion is relieved by retraction of filaments into the discs, which are straightened under tension to form a ramified network. Understanding and controlling these dynamics may provide different avenues to direct pattern formation or template materials.

DOI： 10.1073/pnas.2407914121

Scopus

Publisher：Polymer Journal  

External fields are often present when polymers contact solids, potentially affecting chain adsorption onto a substrate. The adsorbed chains, which are difficult to relax thermally, could semipermanently influence the dynamics of the surrounding chains and bulk chains. In this study, we examined the effect of a force field induced by spin coating on the adsorption of a model polymer chain, DNA. Observations using atomic force microscopy indicated that the morphologies of adsorbed chains were affected not only by the force field but also by the incubation time (tinc) after deposition and before spinning. A longer tinc caused a greater amount of chains to transition from being present in two-dimensional random coil states to stretched states. Conversely, shorter tinc values resulted in many chains being adsorbed in a stretched state. The orientations of the stretched chains reflected the presence of competition between the effects of the centrifugal force and those of the flow rate gradient. At tinc = 0, the adsorbed chains were stretched, and they exhibited many kinks. It was anticipated that this macromolecular information could aid in controlling buried morphologies near solid surfaces and in fabricating promising materials, such as polymer composites and layered organic devices.

DOI： 10.1038/s41428-024-00937-2

Web of Science

Scopus

Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

A better understanding of the dynamic behavior of polymer chains on solid surfaces is indispensable for the design and construction of high-performance polymer composites. We herein visualized the in-plane movement of isolated poly(methyl methacrylate) (PMMA) and poly(tert-butyl methacrylate) (PtBMA) single chains on hydrophilic silicon wafers under ambient conditions by atomic force microscopy. Isolated PMMA chains adsorbed to the substrate, whereas PtBMA chains diffused, the degree of which was dependent on the humidity. Neutron reflectivity revealed the formation of a layer of condensed water on the substrate. All-atomistic molecular dynamics simulations implied that the diffusivity difference of the two polymers was based on the submerged depth in which a part of a chain existed. That is, the interaction of a polymer with the surface of the hydrophilic substrate primarily governs its lateral movement, or adsorption behavior, facilitated by the presence of water.

DOI： 10.1021/acs.macromol.4c00724

Web of Science

Scopus

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Liquid crystal-nanoparticle (LC-NP) hybrid systems allow synergistic interactions between LC matrixes with anisotropic alignment and NP dopants with versatile functionalities. A uniform, well-dispersed, and highly stable thermotropic LC-NP mixture paves the way for further applications. In this work, a linear promesogenic ligand and two types of dendritic promesogenic ligands with alkyl or oligo ethylene glycol (OEG) chains are designed and synthesized to facilitate incorporating NPs into the thermotropic 4-cyano-4 '-pentylbiphenyl (5CB) LC matrix. A comparison study between the linear and the dendritic ligands on the capability to promote miscibility and stability of NPs in LCs is conducted. Miscibility test results show that the linear ligand and the OEG-chained dendrimer both perform well in uniformly dispersing NPs in LCs. Dynamic assemblies of NPs assisted by dendritic ligands and driven by aligning and equilibrating of mesogens are captured, showing the potential of manipulating the assembly of NPs through external thermal stimuli. The stability test shows that both types of dendrimers can significantly enhance the shelf-life time and thermal stability of NPs compared to the linear ligand. In particular, Au NPs capped with OEG-chained dendrimers are stable in 5CB for 6 months at room temperature and over 10 h at 50 degrees C. The synthesis of dendritic ligands is highly modulated and can be generalized onto NPs with different dimensions and properties. Tied by the dendritic promesogenic ligands, this LC-NP hybrid system with good uniformity and stability could be further applied to tunable optical displays, responsive materials, etc.

DOI： 10.1021/acs.chemmater.3c00057

Web of Science

Scopus

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Language：English   Publishing type：Research paper (scientific journal)  

<jats:title>Abstract</jats:title><jats:p>Here we present a microengineered soft-robotic in vitro platform developed by integrating a pneumatically regulated novel elastomeric actuator with primary culture of human cells. This system is capable of generating dynamic bending motion akin to the constriction of tubular organs that can exert controlled compressive forces on cultured living cells. Using this platform, we demonstrate cyclic compression of primary human endothelial cells, fibroblasts, and smooth muscle cells to show physiological changes in their morphology due to applied forces. Moreover, we present mechanically actuatable organotypic models to examine the effects of compressive forces on three-dimensional multicellular constructs designed to emulate complex tissues such as solid tumors and vascular networks. Our work provides a preliminary demonstration of how soft-robotics technology can be leveraged for in vitro modeling of complex physiological tissue microenvironment, and may enable the development of new research tools for mechanobiology and related areas.</jats:p>

DOI： 10.1038/s41598-021-94769-2

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/acsmacrolett.9b00518

Language：English   Publishing type：Research paper (scientific journal)  

<p>We demonstrate the mechanism of “molecular welding” at the polymer–solid interface.</p>

DOI： 10.1039/c7sm02279d

Language：English   Publishing type：Research paper (scientific journal)  

<p>Biocompatible deoxyribonucleic acid (DNA), with high mechanical strength, was employed as the substrate for a Ag nanowire (Ag NW) pattern and then used to fabricate flexible resistor-type memory devices.</p>

DOI： 10.1039/c6cc07648c

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Language：English   Presentation type：Oral presentation (general)  

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Language：Japanese  

Country：Japan  

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Event date： 2024.4

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2024.3

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Country：Japan  

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Language：English   Presentation type：Oral presentation (general)  

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：2