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MXene has tremendous potential for enhancing thermal and tribological properties of fabric composites. Yet, its susceptibility to stacking and weak interfacial adhesion in organic matrix impedes practical application. Herein, MXene-h-BN hybrids were successfully achieved utilizing facile thiol-ene click reaction to introduce hexagonal boron nitride onto the surface of MXene to construct unique hierarchical structure. h-BN is grafted onto MXene through covalent bonding, effectively boosting interfacial adhesion and dispersion in the resin matrix. The layered MXene-h-BN possesses good lubrication behavior, and h-BN can increase strength and thermal conductivity of the MXene support skeleton. The results demonstrate that the thermal conductivity, tensile and bonding strength of reinforced fabric composites are elevated by 43.28%, 34.25% and 43.75% compared with pure fabric composites, respectively. Additionally, the wear rate of reinforced fabric composites is significantly decreased by 63.44%. This paper will contribute a novel and prospective reinforcement design strategy for click reaction constructed nano-materials in tribology. • h-BN was efficiently and promptly grafted onto the surface of MXene through the thiol-ene click reaction. • The structure of 3D point plane network was constructed. • The thermal conductivity, tensile and bonding strength of fabric composites are enhanced by 43.28%, 34.25% and 43.75%. • The reinforced fabric composites create robust tribofilm and wear rate is reduced by 30%. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Abstract In the present work, g-C 3 N 4 nanosheets are prepared by calcination the mixture of urea and melamine. Resulting production is characterized by transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, indicating an effective synthesis of g-C 3 N 4 nanosheets. Phenolic coatings with addition of different content of g-C 3 N 4 nanosheets are used to evaluate the tribological performance of g-C 3 N 4 nanosheets as a role of enhancement phase. Bulk g-C 3 N 4 and graphite are also utilized as fillers to further insight different wear mechanism under dry sliding condition. Experimental results show 1 wt% g-C 3 N 4 nanosheets/phenolic coating exhibit the optimal tribological properties. A higher surface area with more active sites and formation of a continuous transfer film are two important factors for the improvement. Highlights • One-step method was used to prepare g-C 3 N 4 nanosheets. • Tribological performances under various contents were evaluated. • Different wear mechanisms for different fillers were revealed. [ABSTRACT FROM AUTHOR]

The poor interfacial adhesion between hybrid Nomex/PTFE fabric surfaces and polymer materials caused intrinsically by chemical inertness of Nomex and PTFE fibers severely inhibits the further application of hybrid Nomex/PTFE fabric composites. In this study, amino functionalized silane layer (KH550) was immobilized covalently onto hybrid Nomex/PTFE fabric surfaces using bio-inspired polydopamine (PDA) as a bridge to introduce substantial amino groups onto the fabric surfaces. The successful grafting of KH550 on the PDA-coated hybrid fabric surfaces was confirmed by FTIR, XPS and SEM. As a result, the tensile and bonding strength of the amino-functionalized fabric composite were obviously superior to those of the non-treated and polydopamine-coated only, which indicated that the introduction of amino functional layer brought about considerable improvement in interfacial compatibility of hybrid Nomex/PTFE fabric with the phenolic resin matrix. Besides, wear tests also showed the modified fabric composite exhibited the optimal tribological properties under varied test conditions. Most significantly, the strategy presented in this study is substrate-independent along with considerable flexibility to introduce various functional groups, suggesting promising applications for easily improving the interfacial compatibility of reinforcements with polymer matrix. [ABSTRACT FROM AUTHOR]

Researchers have tried to encapsulate various lubricants with kinds of inorganic shell materials forming lubricant microcapsules. In this work, halloysite nanotubes (HNTs) have been employed as nanocontainers for loading ionic liquid (IL) of 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIm]PF 6). To improve the uptake of [BMIm]PF 6 , the lumen is functionalized with sodium laurate (NaL) by electrostatic attractive forces. Besides, a polydopamine (PDA) layer uses as end-stopper to prevent IL premature release. Finally, the obtained PDA-capped [BMIm]PF 6 @halloysite/NaL microcapsules are incorporated into phenolic resin based PBO/PTFE textile composite liner. Results demonstrate that the wear rate decrease from 0.96 × 10−14 m3/(N•m) to 0.51 × 10−14 m3/(N•m) compared with pure composites owing to the robust tribofilm constructed on pin surface. • [BMIm]PF 6 is loaded into the lumen of halloysite nanotubes forming microcapsule. • HNTs constrain the polymer-chain motion, bear and transfer the applied high-loading effectively. • Thermomechanical stress bring about complicated tribochemical reactions forming fluoride, phosphate and ferric oxide. [ABSTRACT FROM AUTHOR]

The novel solvent-free nanofluids (NFs) are prepared by assembling the hybrid Ti 3 C 2 T x @SiCnws nanocores followed by grafting organosilane GPTES and polyether amine M2070. Then Ti 3 C 2 T x @SiCnws NFs are incorporated into the PI/PTFE fabric liners composites (FC) along with tannic acid-PEI (TP) interfacial modification while the tribological performance of FC is systematically investigated. The results demonstrate that the tensile and interfacial strength of FC present effective growth resulting from tannic acid-PEI codeposition modification. Moreover, the addition of Ti 3 C 2 T x @SiCnws NFs further enhances the thermal and mechanical properties of FC due to steric hindrance and entanglement of interfacial molecular chain. The tribological results prove that the improved interfacial adhesion, thermal properties and formation of load-bearing tribofilms are essential for enhanced tribological behaviors of FC. [Display omitted] • Tannic acid-PEI co-deposition coating onto PI/PTFE fabric improves the interfacial adhesion between fabric and resin. • Ti 3 C 2 T X @SiCnws NFs are prepared by electrostatic assembly followed by attaching with organic shell. • Ti 3 C 2 T x @SiCnws NFs promote the lubrication property of FC effectively. • Synergistic effect between Ti 3 C 2 T x and SiCnws is recognized during friction procedure. [ABSTRACT FROM AUTHOR]

Textile-resin composite liners play an important role in aerospace industry owing to the self-lubrication and reinforcement. Herein, PBO (poly(p-phenylene benzobisoxazole) textile-phenolic resin composite liners reinforced with clay were prepared. Results indicated that the addition of kaolin and APL (attapulgite) have improved the wear-resistance of composites owing to the tribofilm and tribo-oxidatio layer (characterized by FIB-TEM). Clay is held together by van der Waals interactions and hydrogen bonds. During rubbing process, clay were exposed, broken and exfoliated releasing plenty of active oxygen atoms and the Si–O dangling bonds, which was contributed to the occurrence of tribo-oxidatio. Besides, ribbon-like APL performed better behavior than kaolin due to the higher specific surface area, more easy exfoliation and rolling bearing effect. [Display omitted] [ABSTRACT FROM AUTHOR]

The high strength of polyphenylene sulfide (PPS) fiber subserves the potential application of PPS fabric composites in the field of tribology, but its interfacial adhesion restricts tribological properties. In this research, the 3-(2, 3-epoxy propoxy) propyl trimethoxy silane (KH560) was used to construct a micro-interface on the surface of the fabric, which can significantly enhance the surface roughness and functional groups. Furthermore, the incorporation of Alpha-zirconium phosphate (α-ZrP), a two-dimensional material with excellent thermal stability and chemical resistance, contributed to ameliorate thermal properties of the fabric composites. The results show that the bonding and tensile strength of the modified fabric composites are increased by 32.6% and 35.8%, respectively. More importantly, the wear rate of the modified fabric composites is reduced by 58.5% compared with the original fabric composites. [Display omitted] • Synergism reinforced PPS fabric composites are acquired by splicing KH560 onto the fabric surface and incorporating laminar α-ZrP. • The attachment of KH560 to the fiber surface results in an improvement in fiber roughness and surface reactive groups. • the application of α-ZrP augments the load-bearing capacity and thermal stability of the composites. • α-ZrP and silane coupling agent have significantly enhanced tribological and mechanical properties of PPS fabric composites. [ABSTRACT FROM AUTHOR]

Preparing nanoparticles with hierarchical structure is a promising approach to improve the interfacial adhesion between additives and polymer matrix. Herein, we exploited hydrothermal carbon spheres (HCSs) decorated with amino-functionalized UiO-66 (UiO-HCSs) to enhance the mechanical and tribological properties of ultra-high molecular weight polyethylene (UHMWPE) composites. Experimental analyses of the morphologies and chemical structure indicate the successful growth of Zr-based metal-organic frameworks (MOFs) on the surfaces of HCSs. The comprehensive studies reveal the beneficial effects of mulberry-like UiO-HCSs nanoparticles on the interfacial properties. The transfer of Zr-based materials onto the steel counterpart also contributes to decrease the wear rate of UHMWPE composites. Furthermore, the present work may pave a route for applying MOFs to tribology. • Decorating carbon spheres with Zr-based MOFs. • Enhancing mechanical and tribological performances of UHMWPE composites by incorporating UiO-HCSs. • Disclosures about different wear mechanisms of UHMWPE composites. [ABSTRACT FROM AUTHOR]

Interfacial strength between reinforcement and polymer matrix and dispersion of lubricant fillers in polymer composites are vital properties in determining the mechanical behaviors and tribological performance. In this work, a facile biomimetic method was employed to improve the interfacial strength between hybrid PTFE/Nomex fabric and phenolic resin as well as the dispersion of carbon carbonaceous in phenolic composite. Dopamine is the main component of mussel adhesive proteins which can easily attach on substrate surface by self-polymerization under weak basic buffer solution. Hence, polydopamine modified graphene oxide (D-rGO) and multi-walled carbon nanotubes (D-MWCNTs) were incorporated into polydopamine functionalized hybrid PTFE/Nomex fabric (D-fabric) composite to improve the tribological performance of the phenolic composite. XPS, TGA, SEM, and TEM characteristics illustrated that the hybrid PTFE/Nomex fabric, graphene oxide (GO), and carbon nanotube (MWCNTs) were successfully functionalized by polydopamine. More importantly, wear test results showed that D-rGO (or D-MWCNTs) reinforced D-fabric phenolic composite exhibited excellent tribological performance. The wear test results and corresponding wear mechanisms of the hybrid PTFE/Nomex fabric composite were discussed in terms of characterizations. [ABSTRACT FROM AUTHOR]

In this work, we investigated the effect of air-plasma treatment on the bonding strength of hybrid PTFE/Nomex fabric and mechanical strength of PTFE and Nomex fibers. Besides, we employed hexagonal boron nitride (h-BN) as high-temperature lubricant and incorporated it into the hybrid fabric/phenolic composite. The high-temperature tribological performances of the fabric composite were evaluated on a pin-on-disk tribometer. The results indicated that the air-plasma treated hybrid PTFE/Nomex fabric composites filled with 6 wt% h-BN exhibited outstanding tribological properties. The results of the morphology study of the fabric composites support the results of the wear test and the corresponding wear mechanisms of the composites were discussed based on the characterizations. [ABSTRACT FROM AUTHOR]