Open Access Research Article Just Accepted
Inspired by spider silk to prepare biomimetic high-performance bovine serum albumin adhesive to strengthen the interfacial and tribological performance of fabric composites
Available online: 18 June 2024
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The interfacial adhesion between fibers and resin matrix is considered to be one of the pivotal elements in determining the comprehensive properties of fabric composites. After years of study and development, it is still challenging to find simple and effective approaches to interfacial modification. Here, with inspiration from the spider silk structure of nature, an efficient and green bionic system was investigated to fabricate a high-performance BSA adhesive through the introduction of chitosan and Ti3C2Tx nanosheets in bovine serum albumin. The Ti3C2Tx nanosheets act as β-sheet nanocrystals in the biomimetic spider silk structure contributing to the creation of a closely cross-linking adhesive system. The results indicate that the wettability and surface activity are significantly enhanced of fiber by the BSA adhesive modification, which efficiently increases the interfacial properties. In comparison with virgin fabric composites, the bonding and tensile strength of strengthened fabric composites increased by 82% and 46.2%. In addition, the strengthened fabric composites have excellent anti-wear performance, with a 62.6% reduction in the wear rate. This paper provides novel ideas for applying biomass adhesives in tribology.

Open Access Research Article Issue
Halloysite‒gold core‒shell nanosystem synergistically enhances thermal conductivity and mechanical properties to optimize the wear-resistance of a pheonlic-PBO/PTFE textile composite liner
Friction 2023, 11 (12): 2238-2252
Published: 29 May 2023
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Polymer-textile liner composites have potential applications in aerospace applications for reducing the abrasion damage of moving parts during operation owing to their self-lubrication, light weight, and high loading capacity. Herein, Au nanoparticles (AuNPs) are successfully loaded into the lumen of halloysite nanotubes (HNTs) to construct an HNTs‒Au peasecod core‒shell nanosystem to optimize the wear resistance of phenolic resin-based poly(p-phenylene benzobisoxazole) (PBO)/polytetrafluoroethylene (PTFE) textile composites. Transmission electron microscope (TEM) characterization reveals that the AuNPs are well-dispersed inside the HNTs, with an average diameter of 6‒9 nm. The anti-wear performance of the HNTs and Au-reinforced PBO/PTFE composites is evaluated using a pin-on-disk friction tester at 100 MPa. Evidently, the addition of HNTs‒Au induces a 27.9% decrease in the wear rate of the composites. Possible anti-wear mechanisms are proposed based on the analyzed results of the worn surface morphology and the cross-section of the tribofilm obtained by focused ion beam transmission electron microscopy.

Open Access Research Article Issue
Surface modification of YS-20 with polydopamine for improving the tribological properties of polyimide composites
Friction 2022, 10 (3): 411-421
Published: 17 March 2021
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Recently, great effort has been devoted to prepare various reinforce fillers to improve polymer performances, but ignoring the importance of raw polymer powders which are indispensable parts of hot-pressed polymer composites. Herein, we engineer raw polyimide (PI) powders with the assistance of polydopamine (PDA) in aqueous solutions. After the modification, polymer powders change from hydrophobic to hydrophilic, which makes it is possible to further modification of polymer powders in liquid phase. During the curing process of modified polymer powders, the partial dehydration of the catechol groups and crosslinking of PDA via C-O-C bonds are confirmed. Based on the features of PDA, a non-destructive mixing method is utilized to realize homogeneous dispersion of multi-walled carbon nanotubes (MWCNTs) in polymer matrix. In comparison with ball milling method, this way can preserve the integrated innate structure of MWCNTs effectively. Besides, by taking full advantage of the reducing and metal-coordination capability of PDA, Cu2+ is successfully loaded onto the surfaces of polymer powders. The related characterizations demonstrate that Cu2+ in situ converts to metallic copper rather than copper oxide during the hot pressing process. The tribological properties of corresponding polymer composites are also studied. These results indicate that modifying polymer powders with PDA is multi-profit and presents practical application prospect.

Open Access Research Article Issue
Fabrication of PTFE/Nomex fabric/phenolic composites using a layer-by-layer self-assembly method for tribology field application
Friction 2020, 8 (2): 335-342
Published: 15 March 2019
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Fabric composites are widely applied as self-lubricating liner for radial spherical plain bearings owing to their excellent mechanical and tribological properties. Nevertheless, the poor interfacial strength between fibers and the resin matrix limits the performance of composites utilized as tribo-materials. To overcome this drawback, a mild layer-by-layer (LbL) self-assembly method was successfully used to construct hybrid fabric composites in the present work. In addition, this investigation addressed the effect of self-assembly cycles on the friction and wear behaviors of hybrid fabric composites under dry sliding condition. The results demonstrate that fabric composites with three or more self-assembly cycles have significantly enhanced surface activities and anti-wear performances. The results obtained in this work can provide guidance in the preparation of self- lubricating liner composites and highlight how the LbL self-assembly techniques could influence the properties of hybrid fabric composites.

Open Access Research Article Issue
Friction and wear behaviors of MoS2-multi-walled-carbon-nanotube hybrid reinforced polyurethane composite coating
Friction 2019, 7 (4): 316-326
Published: 28 July 2018
Abstract PDF (29.8 MB) Collect

MoS2-multi-walled-carbon-nanotube (MWCNT) hybrids containing two-dimensional MoS2 and one-dimensional MWCNTs were synthesized through a one-step hydrothermal reaction. X-ray-diffraction and transmission-electron-microscopy results demonstrated that MoS2 nanosheets were successfully synthesized, and uniformly anchored on the MWCNTs' surfaces. Furthermore, the effects of the MoS2-MWCNT hybrids on the tribological performances of polyurethane composite coatings were investigated using a UMT-2MT tribo-tester. Friction and wear test results revealed that the friction coefficient and wear rate of a 3 wt% MoS2-MWCNT-1 filled polyurethane composite coating were reduced by 25.6% and 65.5%, respectively. The outstanding tribological performance of the MoS2-MWCNT-1 reinforced polyurethane composite coating was attributed to the excellent load-carrying capacity of the MWCNTs and good lubricant ability of MoS2. The surface morphologies of the worn surfaces and counterpart ball surfaces were investigated to reveal the wear mechanisms.

Open Access Research Article Issue
In situ reduction and functionalization of graphene oxide to improve the tribological behavior of a phenol formaldehyde composite coating
Friction 2015, 3 (1): 72-81
Published: 19 March 2015
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The development of a phenol formaldehyde/graphene (PF–graphene) composite coating with high performance is desirable but remains a challenge, because of the ultrahigh surface area and surface inertia of the graphene. Herein, we synthesized PF–graphene composites by the in situ polymerization of phenol and formaldehyde with the addition of graphene oxide, resulting in improved compatibility between the graphene and phenolic resin (PF) matrix and endowing the phenolic resin with good thermal stability and excellent tribological properties. Fourier-transform infrared (FTIR) spectra and X-ray diffraction (XRD) patterns demonstrated that the graphene oxide was reduced during the in-situ polymerization. The PF–graphene composites were sprayed onto steel blocks to form composite coatings. The effects of an applied load and of the sliding speed on the tribological properties of the PF–graphene composite coating were evaluated using a block-on-ring wear tester; in addition, the worn surface and the transfer film formed on the surface of the counterpart ring were studied by scanning electron microscopy (SEM). The results show that the PF–graphene composite coating exhibited enhanced tribological properties under all tested conditions.

Open Access Research Article Issue
Sliding wear behaviors of Nomex fabric/phenolic composite under dry and water-bathed sliding conditions
Friction 2014, 2 (3): 264-271
Published: 05 May 2014
Abstract PDF (11.6 MB) Collect

A Nomex fabric/phenolic composite was prepared, and its tribological properties were evaluated under dry and water-bathed sliding conditions by a pin-on-disk tribometer. The resulting size of the friction coefficient for the Nomex fabric/phenolic composite in the study occurred in the following order: dry sliding condition > distilled water-bathed sliding condition > sea water-bathed sliding condition. The fabric composite’s wear rate from high to low was as follows: distilled water-bathed sliding condition > sea water-bathed sliding condition > dry sliding condition. Under water-bathed sliding conditions, penetration of water into the cracks accelerated the composite’s invalidation process, resulting in a higher wear rate. We also found that the extent of corrosion and transfer film formed on the counterpart pin significantly influenced the wear rate of the Nomex fabric composite. Discussion of the Nomex fabric composite’s wear mechanisms under the sliding conditions investigated is provided on the basis of the characterization results.

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