Publications

It remains challenging to simultaneously realize mechanical robustness, malleability, and functionality in elastomers via facile yet efficient methods. Herein, a simple strategy for the biomimetic heterogeneous design is proposed to achieve mechanically strong, malleable, and functionalized elastomers. We demonstrate the strategy by straightforward mechanical mixing of a highly cross-linked vitrimeric elastomer with a homogeneous gum and subsequent curing, resulting in heterogeneous vitrimeric elastomers (hetero-VEs). The hetero-VEs comprise two phases: a hard phase with dense cross-links and a soft matrix with few cross-links, with excellent interface between the two phases. The hard phases can be deformed upon loading, dissipating energy, which significantly improves the overall mechanical performance of the hetero-VEs. When conductive fillers are incorporated into the soft matrix, due to the volume exclusion effect of the hard phases, the resultant hetero-VEs exhibit high conductivity with a small fraction of fillers. In view of the facile and generic preparation process, this strategy should be a promising way to reinforce and functionalize many vitrimeric elastomer systems.

Janus membranes are widely used in fields such as oil-water separation and wound dressings due to their asymmetric wetting properties. However, the weak interface binding force between the hydrophobic and hydrophilic layers can affect the liquid transport performance and membrane separation. In this study, we have reported a method using self-induced crystallization to grow shish-kebab (SK) structures in electrospinning polylactic acid-based fiber membranes. Peel testing revealed that the peel load after induced crystallization increased from 0 to 0.05 N to 0.05–0.15 N, and the time for droplets to penetrate from the hydrophobic side to the hydrophilic side decreased from 16S to 3S. This indicates that SK structures can enhance the adhesion between the hydrophilic and hydrophobic interface, as well as facilitating droplet transport. Through the oil-water separation experiment, it was discovered that the presence of SK structures can filter out more microemulsions. For different emulsions (kerosene, petroleum, n-hexane, petroleum ether, tea tree oil), the separation efficiency of Janus-SK membrane increased by 1.67 %, 2.5 %, 3.0 %, 9.7 %, 4.3 %, respectively. The development of Janus membranes has been provided with a new direction.

It remains a huge challenge to realize the homogeneous graphene dispersion in elastomer matrix by a simple and general compounding method. Herein, we develop a straightforward slurry compounding method for preparation of rubber/graphene composites with well-dispersed graphene. Specifically, TPG (tea polyphenol reduced graphene)/ethanol slurry was first collected by solvent exchange after the reduction of graphene oxide by tea polyphenol and then directly melt compounded with chlorosulfonated polyethylene (CSM) in a two-roll mill to produce the composites. As revealed by the XRD and morphological studies, TPG homogeneously dispersed in CSM matrix, which together with the strong interfacial interaction between TPG and CSM contribute to the remarkable improvement in mechanical properties of the resulted composites. We envision that the present work offers a straightforward yet effective methodology for preparing high-performance elastomer/graphene composites via conventional melt compounding.

The increasing demand for hydrogen peroxide (H₂O₂) necessitates greener production methods. In response, we developed an iodine-nitrogen-codoped metal-free carbon catalyst using the coordination microstructure regulation strategy, combined with rapid Joule heating for precise iodine and nitrogen doping. This approach allows precise control over the formation of active iodine-nitrogen coordination sites, significantly enhancing the catalytic performance for H₂O₂ production via the two-electron oxygen reduction reaction. Among the synthesized catalysts, I-N₄ demonstrated superior catalytic activity, achieving a high H₂O₂ selectivity of 90-96% and a production rate of 1265 mg L^-1 h^-1 at -0.4 V vs reversible hydrogen electrode. Operando Raman spectroscopy confirmed the dynamic evolution of intermediates during the reaction, while chronoamperometric tests showed long-term stability. This scalable, energy-efficient synthesis method offers significant potential for sustainable energy and environmental applications.

Naturally occurring nanotubular halloysite exhibits a number of interesting characteristics, which make it a promising candidate for fabricating polymer-based nanocomposites for engineering and functional applications. The main attractive features of halloysite include its high mechanical strength/modulus, special lumen structure, essential noncytotoxicity and ability to regulate crystallization and enhance thermal stability. In this chapter, the processing methods, interfacial modifications and multiple effects of halloysite for halloysite polymer nanocomposites are discussed. The structural benefits of halloysite and distinctions of halloysite polymer nanocomposites are also highlighted.

The Ru–Fe 4 C/NCNF (Ru : Fe = 1 : 6) catalyst exhibits excellent catalytic performance ( η 10 = 106 mV and η 100 = 254 mV). The prepared catalyst can be used as a self-supporting working electrode and it shows excellent stability.

To introduce thiol–ene chemistry in the modification of composites by ionic liquid (IL), a novel functional IL, 1‐methylimidazolium mercaptopropionate (MimMP), was synthesized and investigated as a modifier for styrene–butadiene rubber/silica composites. MimMP could be hydrogen‐bonded with silica and react with the double bonds of rubber chains via thiol–ene chemistry. The filler networking, curing behavior, filler dispersion, crosslink density, and mechanical performance were fully studied. The filler networking in the uncured rubber compounds was effectively restrained. The vulcanization was largely accelerated by MimMP. The interfacial interaction was quantitatively evaluated and found to consistently increase with increasing MimMP. The mechanical performance and abrasion resistance of the modified vulcanizates improved considerably. The remarkable improvements were mainly ascribed to the improved interfacial structure comprised of MimMP–silica hydrogen bonding and MimMP–rubber covalent bonds via thiol–ene chemistry. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

The development of advanced elastomers with a combination of high strength, large extensibility, and excellent flex-cracking resistance is a huge challenge. In this contribution, we proposed a novel strategy to engineer a multinetwork by incorporating weaker sacrificial hydrogen bonds and stronger Zn-based units into a chemically cross-linked cis-1,4-polyisoprene network. The dynamic nature allows the sacrificial bonds to be ruptured and re-formed, resulting in high stretchability. During external loading, the sacrificial bonds rupture prior to fracture of the covalent network, thus dissipating energy efficiently and facilitating chain orientation to produce improved tensile modulus and fracture toughness as well as significant enhancement of flex-cracking resistance. We propose that the enhanced cracking resistance may originate from the energy dissipation and re-forming of sacrificial bonds, a new mechanism alternative to strain-induced crystallization. Overall, this concept provides unique inspiration for the design of advanced elastomers with excellent mechanical properties under both static and dynamic conditions.

Recent progress in introducing elegant dynamic covalent bonds into covalently crosslinked networks enabled the trade-offs between chemical crosslinking and recycling. Thus far, continuous efforts are made to exploit new dynamic chemistries to address the constrains of intricate preparation procedures and need of catalyst additives in creating dynamic covalent networks. In this work, we report an industrially feasible process to prepare catalyst-free malleable elastomers by engineering dithioacetals as the dynamic motifs into a commercial diene rubber. Specifically, a dithioacetal-containing diacid (BTA) is synthesized and used as a novel crosslinker for epoxidized natural rubber (ENR), by which dynamic dithioacetals are introduced into the elastomeric networks. Small molecule model study shows that dithioacetal exchange can be conducted at elevated temperature without catalyst. In the BTA crosslinked ENR, the thermoactivated dithioacetal exchange reactions can alter its network topologies in an associative pathway and confer it with remarkable reprocessability. The mechanical properties and relaxation rate of the networks can be readily manipulated by varying the dithioacetal concentration.

Front Cover: Unlike the normal pristine MMT particles, which are compact and plane-shaped, these spray-dried pristine MMT particles display extraordinary flower-shaped morphologies. This indicates that the rapid evaporation process brought about by the spray-drying method achieves structures made of randomly arranged MMT layers in the granule. Further details can be found in the article by M. Lu, Y. Wang, Y. Wu, Y. Quan, X. Wu, L. Zhang,* and B. Guo on page 20.

Carbon black (CB) is an irreplaceable filler in the rubber industry, due to its unparalleled cost performance. Nevertheless, the poor CB dispersion in the rubber matrix significantly compromises the overall performance of the composites, especially in the aspect of hysteresis loss. Herein, a novel adamantyl-based imine (DADI) was synthesized and then adopted as the interfacial mediator of natural rubber/CB composites. As demonstrated, the imine moieties on the DADI skeleton are capable of capturing the macroradicals generated by the scission of rubber chains during compounding, followed by stabilizing inside the adamantyl functionalities. These DADI-capped macroradicals can further transfer to the energy traps on the CB surface through electron cloud sharing, which enables strong interfacial adhesion between rubber matrix and CB and hence improves the dispersion state of CB particles. Consequently, with the incorporation of 1phr DADI, the resulting composite achieves remarkable decreases of approximately 6 °C in heat generation and 21% in energy loss. Besides, the aging resistance of the resulting samples is also considerably improved due to the capability of DADI to wipe out reactive radicals. We envisage that the synthetic DADI has great potential to prepare high-performance tire products in terms of low energy loss and superior aging resistance.