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Article
Publication date: 2 January 2018

Hongsheng Luo, Xingdong Zhou, Yuncheng Xu, Huaquan Wang, Yongtao Yao, Guobin Yi and Zhifeng Hao

This paper aims to exploit shape-memory polymers as self-healable materials. The underlying mechanism involved the thermal transitions as well as the enrichment of the…

Abstract

Purpose

This paper aims to exploit shape-memory polymers as self-healable materials. The underlying mechanism involved the thermal transitions as well as the enrichment of the healing reagents and the closure of the crack surfaces due to shape recovery. The multi-stimuli-triggered shape memory composite was capable of self-healing under not only direct thermal but also electrical stimulations.

Design/methodology/approach

The shape memory epoxy polymer composites comprising the AgNWs and poly (ε-caprolactone) were fabricated by dry transfer process. The morphologies of the composites were investigated by the optical microscope and scanning electron microscopy (SEM). The electrical conduction and the Joule heating effect were measured. Furthermore, the healing efficiency under the different stimuli was calculated, whose dependence on the compositions was also discussed.

Findings

The AgNWs network maintained most of the pathways for the electrons transportation after the dry transfer process, leading to a superior conduction and flexibility. Consequently, the composites could trigger the healing within several minutes, as applied with relatively low voltages. It was found that the composites having more the AgNWs content had better electrically triggered performance, while 50 per cent poly (ε-caprolactone) content endowed the materials with max healing efficiency under thermal or electrical stimuli.

Research limitations/implications

The findings may greatly benefit the application of the intelligent polymers in the fields of the multifunctional flexible electronics.

Originality/value

Most studies have by far emphasized on the direct thermal triggered cases. Herein, a novel, flexible and conductive shape memory-based composite, which was capable of self-healing under the thermal or electrical stimulations, has been proposed.

Details

Pigment & Resin Technology, vol. 47 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 28 May 2020

Hongsheng Luo, Yangrong Yao, Huankai Zhou, Shaoying Wu, Guobin Yi, Xuran He, Jiyuan Yang, Yan Jiang and Zhengwen Li

The purpose of this paper is to study the interfacial effect on mechanical properties of the cellulose nano crystal (CNC)–shape memory polymer (SMP) composites by using…

Abstract

Purpose

The purpose of this paper is to study the interfacial effect on mechanical properties of the cellulose nano crystal (CNC)–shape memory polymer (SMP) composites by using combination of the theoretical and experimental approaches.

Design/methodology/approach

SMP composites were fabricated by introducing CNCs into crystalline shape memory polyurethane. The morphological, thermal and mechanical properties were comprehensively investigated. Theoretical approach based upon the percolation model was used to simulate the storage modulus E’ variation of the composites in crystalline and amorphous states, respectively. The classic two-phase percolation model was used for the amorphous-state composites. Furthermore, a three-phase model consisting of interfacial regions was created for the crystalline-state composites.

Findings

The deviation of nano fillers mechanical reinforcements was disclosed as the composites triggered thermal transitions. Modified percolation theory involving the interfacial effects greatly enhanced the simulation accuracy.

Research limitations/implications

The study made the traditional percolating theory suitable for dynamic modulus and polymorphs polymers in terms of mechanics, which may extend the potential application.

Originality/value

The findings may greatly benefit the development of novel interfacial reinforcing theory and intelligent polymeric nanocomposites featuring polymorphs and dynamic properties.

Article
Publication date: 2 January 2018

Pei Qin, Guobin Yi, Xihong Zu, Huan Wang, Hongsheng Luo and Miao Tan

The aim of this paper is to synthesize graphene-modified titanium dioxide (GR-TiO2) nanorod arrays nanocomposite films, so that these can enhance the photocatalytic…

Abstract

Purpose

The aim of this paper is to synthesize graphene-modified titanium dioxide (GR-TiO2) nanorod arrays nanocomposite films, so that these can enhance the photocatalytic properties of titanium dioxide and overcome the problem of difficult separation and recovery of photocatalysts.

Design/methodology/approach

The GR-TiO2 nanocomposite films were synthesized via hydrothermal method and spin-coating. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), ultraviolet–visible (UV-Vis) diffuse reflectance spectrum and Raman spectrum. The photocatalytic performance of the GR-TiO2 nanocomposite films for degrading Rhodamin B under ultraviolet (UV) was studied by a UV-Vis spectrophotometer. The photocatalytic enhancement mechanism of graphene was studied by photoelectrochemical analysis.

Findings

The introduction of graphene expanded the range of the optical response of TiO2 nanorod arrays, improving the separation efficiency of the photogenerated electron-hole pairs, and thus dramatically increasing its photocatalytic performance.

Research limitations/implications

A simple and novel way for synthesizing GR-TiO2 nanocomposite films has enhanced the photocatalytic performance of TiO2.

Originality/value

The photocatalyst synthesized is easy to separate and recycle in the process of photocatalytic reaction, so it is possible to achieve industrialization.

Details

Pigment & Resin Technology, vol. 47 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

Book part
Publication date: 2 August 2006

Lei Xie and Arthur P.J. Mol

This chapter explores the characteristics of emerging environmental movement organizations in China, and more specifically the role of guanxi – or personal networks – in…

Abstract

This chapter explores the characteristics of emerging environmental movement organizations in China, and more specifically the role of guanxi – or personal networks – in Chinese environmental activism. While organizational networks of environmental NGOs are still weak in Chinese environmental activism, personal networks of environmental activists are instrumental in building the first sprouts of a green civil society. We explore this via an in-depth case study of relatively successful environmental activism to halt the construction of a number of hydro-electric projects on the Nu River. The case study illustrates that in China, more so than in western countries, informal personal networks, rather than formal organizational networks, play a crucial role in the organization and success of contemporary environmental campaigns. This is partly explained by the immature environmental movement, and partly by the specifics of Chinese social networks.

Details

Community and Ecology
Type: Book
ISBN: 978-1-84950-410-2

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