Electrospun nanofibre interleaving has a great potential for toughening of composite laminates as an effective, safe and industrially relevant method. Although many studies showcase large increases in delamination resistance, these are typically obtained under either Mode I or Mode II loading and for a wide variety of nanofibres. Here, we present a more general approach towards simultaneous excellent Mode I and Mode II delamination resistance using a single nanofibre system without the need for additional chemical modification steps or speciality polymers. It is illustrated based on the concept of interdiffusion of polycaprolactone nanofibres during the curing process into the epoxy matrix resin for improved adhesion. The results show that for a simultaneous increase in Mode I and Mode II delamination resistance, the adhesion and the fibre morphology of the nanofibres are crucial. The methodology is then expanded to allow for industrial relevant working windows by core-shell structured polyamide/polycaprolactone nanofibres. This approach results in a of 650 ± 50 J m-2 (+ ca. 60% vs. virgin material) and a of 3160 ± 35 J m-2 (+ ca. 60% vs. virgin material).
In this study, various amounts of carbon nanotubes (CNTs), nanosilver (AgNPs), and polyaniline (PANI) were incorporated at the same pot into the structure of composite polyacrylonitrile (PAN) nanofibers, which were produced by electrospinning process in order to see synergistic effect of the additives on the final properties of the composite materials. Performance and characteristic properties of composite nanofibers were analyzed by tensile tester, electrical conductivity meter, Fourier Transform Infrared Spectroscopy, differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, and antimicrobial activity test. Statistical analysis (analysis of variance) was performed to see whether the differences were statistically significant or not. It was seen that samples with AgNPs had higher breaking strength and electrical conductivity than the samples with CNTs. Generally, PANI improved the crystallinity of the composite material more than the nanoparticles (CNTs and AgNPs). Even though each of the nanoparticles was used in low concentrations, the composite materials (PAN–1CNT–1AgNO3–R and PAN–PANI–1AgNO3–R) gained antimicrobial properties due to the synergistic effect of additives. The results suggested that PAN composite nanofibers with 3 wt% PANI and 1 wt% AgNO3 generally presented better performance than the other samples in terms of electrical conductivity, antimicrobial activity, mechanical strength, crystallization, and thermal stability.
There are many studies which use different types of reduction methods that affect the final properties of composite material containing silver nitrate (AgNO 3 ). The use of poly(N-vinylpyrrolidone) (PVP) in the composite also affects the final properties of composite material. However, as seen from the literature, it is difficult to find any studies focusing on polymer composite nanofibers reduced using different reduction methods and studies with different PVP loadings which are compared to each other, although it is very important to determine the most suitable reduction method and PVP loading for final composite properties. Thus, in this work, the effect of different reduction methods on polyacrylonitrile (PAN) composite nanofibers incorporating AgNO 3 and the comparison of different amounts of stabilizer (PVP) are studied in detail to determine the most suitable reduction method and the effect of PVP loading on the structure and the properties of the final product. PAN composite nanofibers having different amounts of PVP are reduced by four different methods namely arc-sol method, hydrazine method, arcweb method, and reflux method and characterized by electrical conductivity, mechanical testing, and thermal and SEM analyses. It has been observed that the hydrazine method provides higher breaking strength, electrical conductivity, enthalpy, smallest diameter, and lower cyclization temperature (T c ) than other reduction methods. Presence of PVP results in an increase of breaking strength and cyclization temperature, a decrease of enthalpy and the electrical conductivity. While highest breaking strength was obtained by hydrazine reduction with highest PVP loading, highest electrical conductivity was obtained by hydrazine reduction without PVP. As a direct result of the incorporation of AgNO 3 with or without PVP, insulator pure PAN (10 -12 S/cm) becomes semi-conductive material (10 -7 S/cm), which can be used as an antistatic material.
The effect of dispersion technique, reduction method, and the amount of silver nanoparticles on the properties of composite polyacrylonitrile nanofiber containing silver nanoparticles is analyzed using differential scanning calorimetry, scanning electron microscopy, electrical conductivity, tensile testing, X-ray diffraction, and antimicrobial efficiency measurements.Composite nanofibers reduced by hydrazine hydroxide result in smaller diameter, higher electrical conductivity, higher breaking strength, higher cyclization enthalpy than the samples reduced by xenon arc method. Reduction process results in smaller diameter and higher breaking strength than those of non-reduced nanofiber web containing AgNO 3 nanoparticles. Dispersion by ultrasonic homogenizer/bath provides higher breaking strength, electrical conductivity than the samples dispersed by only magnetic stirrer. An increase of silver nanoparticle generally results in an increase of enthalpy, a decrease of both cyclization temperatures and crystallinity. While 1 wt% AgNO 3 loading is suitable for high breaking strength, 3 wt% AgNO 3 loading is suitable for both high electrical conductivity and antimicrobial properties. Insulator polyacrylonitrile polymer becomes a semiconducting material.
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.