Guowei Chen

• Ph.D
• PostDoc Position at University of Waterloo

Statement of significance: The mechanical behaviors during the whole fracture process of bamboo were investigated by acoustic emission (AE). During the fracture process there were three kinds of fracture behaviors recognized by AE: matrix (parenchyma cells) failure, interfacial (fiber/fiber or fiber/parenchyma cell walls) dissociations and fiber b...

Natural gradientfibrous bamboo bended from two opposite directions (divided as Type I and Type IIsamples) showed pronounced asymmetricflexural performances as the water contents graduallyincreased (0%, 6%, 22% and 35%). The real-timeflexural deformation and fracture behaviors were detectedand analyzed with the aid of acoustic emission (AE). Results...

Structural calcites, aragonites, and the bonding organic network decide the growth, structure and mechanical properties of the mollusk bivalvia shell. Here, it was found out that the calcite prisms together with the coated organics construct another kind of ‘brick and mortar’ structure similar to the aragonite tablets. The calcite layer can be divi...

Porous polymer materials, including polymer foams and melt-blown fibers, have nano or micro-size pores and a large specific surface area that endows them with great potential as engineered oil ad/absorption materials. This review provides an overview of the recent developments in the processing of polymer foams and melt-blown fiber-based porous pol...

Natural bamboo has potential as a sustainable alternative to petroleum-based lightweight materials. However, its sensitivity to environmental conditions limits its usage. Here, we improved the traditional alkali treatment densification process by innovatively transporting Fe 3 O 4 nanoparticles (NPs) into the interior of natural bamboo without any...

The compression properties of natural bamboo were tested, and the crush morphologies with different moisture contents and fibrous structure were observed. Real-time acoustic emission (AE) and optical microscope videos captured the compression behaviors. Dry bamboo internodes showcased 100% higher compression strength with shearing as the predominan...

This study aims at evaluating and developing an environmental‐friendly and sulfur‐free cured Ethylene Propylene Diene Monomer (EPDM) composites. Silane grafted EPDM (SiEPDM) composites incorporated with silica was prepared via a solvent‐free, one‐step reactive mixing process. The silane grafting and silica filler bonding were characterized using FT...

Ethylene propylene diene monomer (EPDM) rubber based bio-composites filled with silane-modified wood fiber (SiWF) were foamed by using chemical foaming method. The SiWF and the incorporation of dicumyl peroxide (DCP) generated crosslinking in the developed EPDM bio-composite foams, which showed much lower water absorption and improved thermomechani...

Epoxidized natural rubber (ENR) bio‐composites filled with hemp hurd were fabricated via reactive batch‐mixing and vulcanization. The effect of the ENR‐hemp hurd grafting, silane modification, sulfur vulcanization, and the built‐up crosslinking networks on the thermomechanical and physical properties were analyzed. It was observed that the reactive...

Sustainable hybrid fillers including biocarbon (BioC) and recycled carbon fibers (rCF) are used to reinforce the polyphenylene sulfide (PPS). The PPS biocomposites were compared with the conventional talc filled counterparts. The PPS/BioC/rCF biocomposites have comparable specific mechanical properties and thermal stability to the PPS/talc/rCF comp...

The nutshell waste streams (pine nut shells (PNS), walnut shells (WNS), and almond shells (ANS)) were effectively converted into biocarbon materials employing slow pyrolysis in a fixed bed horizontal reactor at 500 and 900 °C with a 10 °C min⁻¹ heating rate and 60 min holding time. The acquired biocarbon materials were then characterized to underst...

The silane modification by melt mixing and the subsequent moisture curing of ethylene propylene diene terpolymer (EPDM) was optimized based on the Design of Experiments (DOE). The optimum moisture-cured Si-EPDM samples displayed a 101.7% and 36.5% improvement in the tensile strength and modulus, respectively, compared to the pristine EPDM. The cure...

Ethylene propylene diene monomer (EPDM) bio-composites filled with silane-modified wood fiber (Si-WF) were fabricated by melt batch mixing and compression molding. The effects of fiber loading, silane modification, and in situ cross-linking on the water absorption, thermal, and mechanical properties were investigated. Due to the reduced surface ene...

Polyphenylene sulfide (PPS) is a type of thermoplastic that has high thermal and mechanical performances and extensive applications. Before processing, pre‐curing is required to improve its processability and mechanical properties. Here, effects of curing temperature (245 and 260°C) and time (10, 30, 60, and 120 min) on structure and thermal‐mechan...

To investigate the thickness evolution of nanocellulose in water, in situ SAXS (small angle X-ray scattering) was used to characterize bamboo fibers. The thickness of nanocellulose was calculated by ln I(q)−q2 curve and the results indicated that the thickness of nanocellulose decreased (from 13.38 ± 2.358 nm to 8.77 ± 0.98 nm) in the first 6 h, th...

Natural bamboo node samples bended from two opposite radial directions (Type I and Type II) displayed asymmetric flexural fracture process and behaviors. The real-time flexural process and fracture behaviors were observed and analyzed with the aid of optical video microscopy and acoustic emission (AE). Results indicated there are three kind of frac...

Polyphenylene sulfide (PPS) is a type of thermoplastic polymer with high thermal and mechanical performance that has wide applications in various industries, such as precise electronics, electrical devices, chemical containers, automobile and aerospace components, etc. By adding carbon in different forms (including carbon fibers, carbon nanotubes,...

Bamboo is widely planted in the world and many species of bamboo are intensively used as sustainable bio-composite materials in the construction of houses, pavilions, furniture and bridges, etc. The bamboo nodes play an important role on natural bamboo's strength. This paper is focused on the structure-property-fracture relations of the natural Mos...

Turtle rib is a kind of bio-composites with excellent fracture resistance and toughness, whose composition and structure were characterized by X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM), which indicated that the turtle rib has woven hierarchical fibrous and sandwich structure. With the aid of acoustic emissio...

Effects of the welding inclusions and notches on the deformation and fracture behaviors of low-alloy steels were investigated by combining the tensile performance testing and acoustic emission (AE). The micro-structures and fracture surfaces of the hot-rolled and welded samples were observed by OM and SEM. It was found out that the welding inclusio...

Polydicyclopentadiene/nano-CaCO3 composite was prepared by frontal polymerization with classical ring-opening metathesis catalyst system. The micromorphology and thermal property as well as mechanical properties of the composites were studied. The SEM indicates that the nano-CaCO3 particles are dispersed in polydicyclopentadiene matrix at the nanos...

Polydicyclopentadiene (PDCPD) foam can be made by chemical blowing method. The influence of catalysts proportion, mold temperature and content of blowing agent on the properties of PDCPD foams was investigated. The results indicate that when the mold temperature gets 60~70℃, the catalysts proportion (n(DCPD/n (WCl6·WOCl4)/n(AlEt2Cl)) is about 1300/...

In order to obtain multiwalled carbon nanotubes (MWNTs)/epoxy composites with good mechanical properties at cryogenic temperature, two methods were adopted to modify MWNTs. MWNTs were first treated by acid mixture (oxidized MWNTs, O-MWNTs) and then maleic anhydride (MA) and isophorone diisocyanate (IPDI) grafting was carried out. Fourier transform...

Epoxies have a wide range of applications in fuel tank fabrication, aerospace, electrical, electronic, and automobile industries. However, these resins are quite brittle, showing poor mechanical performance, especially at cryogenic temperature. The properties of functionalized multi-walled carbon nanotube (MWCNTs)-reinforced epoxy composites were i...