Base on engineering application need, the subject introduce microcapsule that contains adhesive into cementituous composite for realizing the self-healing characteristics of cracked concrete. The technique has good industry feasibility, process operability, and reproducibility of self-healing characteristic. It is can resolve partial problems that other current self-healing methods are facing.
Inspired by the application of nano‐fillers in composite materials, well‐dispersed aramid nanofibers (ANFs) were prepared and added into the epoxy resin (EP) to improve the toughness and tenacity properties of the ANF/EP composites. The composites were characterized by mechanical property test, surface analysis, thermodynamic property analysis, and contact angle. Results showed that when the EP was added with 0.15 wt% ANF, the tensile strength, bending strength, and impact strength are increased by 28.2%, 81.9%, and 81.8% compared with pure EP, respectively. The thermal stability and infiltration of the composites are improved. The interlaminar shear strength and interfacial shear strength of the aramid fiber were increased by 53.1% and 92.7% compared with the not reinforced EP, demonstrating that the epoxy reinforced with ANF is also beneficial for improving the interfacial bonding strength of aramid fiber and EP. The mechanism of the epoxy reinforcement by ANF and the interface enhancements showed that the ANF could cause several crack bridges and strong hydrogen bond interaction interface.
This study addresses the effect of the coatings prepared from aramid nanofibers (ANFs) on the surface treatment of aramid fiber and reinforced polycarbonate (PC) composite (AF/PC). Aramid fiber's smooth, inert surface bonds poorly with polycarbonate. In this research, the PC‐ANF coating was made by the PC/CH2Cl2 solution, which was modified by aramid nanofibers to improve the interfacial adhesion and compatibility of aramid fiber/PC composites. What's more, the silane (KH570) was added to improve the dispersion and interfacial strength of ANF and PC. The results showed the water contact angle of the aramid fiber modified by PSi‐ANF coating was reduced, indicating the modified fiber has a better wettability. The interfacial bonding strength between PC and aramid fiber increased by 77.2%. The AF/PC composites were prepared by hot‐compression, which the aramid fiber wovens treated with P‐ANF coating, PSi‐ANF coating. The tensile strength, flexural strength, interlaminar shear strength, and impact strength of the AF/PC composite reinforced by AF treated with PSi‐ANF containing 2.0 wt% ANF increased by 62.0%, 81.9%, 49.5%, and 27.6%, respectively. Therefore, this study demonstrates that incorporating ANF interphase may offer an innovative and practical way for enhancing the interface bonding properties of aramid‐reinforced composites.
Effect of microcapsules on cement composites has been studied. The hydration of cement composite using microcapsules is studied by XRD and thermal techniques, showing that the addition of microcapsules has little affect on the hydration of cement. The pore size distribution and surface area of the cement composite with microcapsule are analyzed, showing a reduction in the pore content of cement composite and makes the pores smaller, which would improve durability and impermeability for designed materials. Damaging on cement and composites containing microcapsules and self-healing of these damagings can be reflected by the changes in their bending strength. When the cracks were generated in the composite, the microcapsules can release adhesive to fill in the space between the crackings, preventing cracking further growth.
Poor dispersion is a major disadvantage of aramid pulp (AP) reinforced composites. In this study, nano-silica (SiO 2), as the surface modifier and reinforcing agent, was synthesized on AP surfaces to improve the dispersed character in ethylene-propylene-diene elastomer (EPDM) using supercritical carbon dioxide (scCO 2). The influence of the temperature of scCO 2 on treated AP, configuration of the surface, and mechanical performance of AP/EPDM composites were studied. Based on the results of Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, SiO 2 was chemically grafted onto the AP surface. The SiO 2 nanoparticles were uniformly deposited on the AP surface, and the roughness of AP was increased based on the SEM results. The optimum temperature of the supercritical reaction was 100 C considering the results of all the tests. Under the optimum temperature and with 10 phr of AP, the mechanical properties, oil resistance, and dynamic mechanical properties of the SiO 2-AP/ EPDM composites were investigated. The tensile strength and tear strength of the SiO 2-AP/EPDM were improved by 121.1 and 134.9%, respectively, compared with that of the pure AP/EPDM composites. The fracture surface of the SiO 2-AP/EPDM composites showed that SiO 2-modified AP had a good dispersion in EPDM, and AP and EPDM had good interfacial bonding. Dynamic mechanical analysis results showed that the storage modulus of the composites was improved greatly compared with the pure AP/EPDM, and the loss factor also increased. The oil resistance of the composites was also improved.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.