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Your search keyword '"Huang, Yiwan"' showing total 69 results
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69 results on '"Huang, Yiwan"'

54. Multistructural Network Design Enables Polybenzoxazine to Achieve Low-Loss-Grade Super-High-Frequency Dielectric Properties and High Glass Transition Temperatures

Author

Zeng, Ming, Tan, Dengru, Feng, Zijian, Chen, Jiangbing, Lu, Xiang, Huang, Yiwan, and Xu, Qingyu

Abstract

An original design strategy for the preparation of thermosetting resins with both super-high-frequency low dielectric constant (k) and low dielectric loss (f) as well as high glass transition temperature (Tg) values is presented. The key to this design strategy is incorporating a bulky group and reactive furan ring to increase the free volume and the cross-linking density, respectively. The formed multistructural networks (relatively dense near furan rings and relatively loose near bulky groups) are beneficial not only for lowering kvalues but also for maintaining high Tgs of main-chain benzoxazine copolymers. More importantly, the optimized copolymers possess low fvalues (≤0.008) under 5 and 10 GHz, satisfying the requirement of super-high-frequency communications. The correlations between the free volume and thermal and dielectric properties are also discussed to understand the synergistic mechanism. The work opens a new route for the structural design and preparation of super-high-frequency low dielectric functional polymeric materials.

Published
2022
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68. Super Bulk and Interfacial Toughness of Amylopectin Reinforced PAAm/PVA Double‐Network Hydrogels via Multiple Hydrogen Bonds.

Author

Zhang, Yikun, Li, Dapeng, Huang, Yiwan, Long, Shijun, Li, Haiyan, and Li, Xuefeng

Subjects
AMYLOPECTIN, HYDROGEN bonding, BULK solids, HYDROGELS, POLYVINYL alcohol, POLYACRYLAMIDE, FLEXIBLE electronics, TENSILE strength
Abstract

A simple, multiple‐hydrogen‐bond approach to fabricating physically crosslinked, Amylopectin reinforced polyacrylamide/poly(vinyl alcohol) (Amy/PAAm/PVA) double‐network (DN) hydrogels with super toughness in bulk and at solid interfaces is reported. The Amy/PAAm/PVA DN hydrogels exhibit high tensile strength (854.1 kPa), high extensibility (≈eight times), high bulk toughness (4094.8 kJ m−3), good self‐recovery property (≈92% of self‐recovery at room temperature), and strong adhesion to nonporous glass surfaces (≈158 kPa). Such tough and adhesive DN hydrogels have great potential for various applications in engineering artificial soft tissues, flexible electronics, and wearable devices. [ABSTRACT FROM AUTHOR]

Published
2020
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69. Multi-structural network design and mechanical properties of graphene oxide filled chitosan-based hydrogel nanocomposites.

Author

Chen, Jiangbing, Xu, Qingyu, Huang, Yiwan, Zeng, Ming, and Wang, Yanqing

Subjects
*CHITOSAN, *GRAPHENE oxide, *OXIDES, *HYDROGELS, *NANOCOMPOSITE materials, *MECHANICAL properties of metals
Abstract

Chitosan (CS), a linear natural polysaccharide, is often chosen to prepare hydrogels due to its hydrophilic nature and biocompatible merits. However, mechanically weak CS-based hydrogels show limited applications. Herein, we show a new multi-structural network design for mechanically enhancing graphene oxide (GO) filled CS-based hydrogel nanocomposites. The designed multi-structural hydrogel network shows a relatively dense structure with surrounding polymer chains at the local zone of self-assembled GO-CS units and a relatively loose structure at the far zone, resulting in the mechanical enhancement. By tuning GO loading and molecular weight of CS in a specific range, we intend to understand the effect of the specific multiple network structures on the mechanical properties of the composites. The experimental results demonstrate that the multi-structural network design provides an effective reinforcement mechanism for the hydrogel composites. The composite (containing only 0.30 wt% GO and ≈90 wt% water) has achieved 163% and 91% increases in compressive strength and work of compression, respectively, comparing to those of the neat gel. The findings may be generally applicable for the structural design and understanding of nanofiller-reinforced hydrogel and elastomer composites. [ABSTRACT FROM AUTHOR]

Published
2018
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