Improvement of the Mechanical Properties by Surface Modification of ZnCl2 and Polydopamine in Aramid Fiber Composites

Abstract

Although aramid fiber has the advantage of excellent chemical and mechanical properties, the performance of the composites may be reduced due to the low interfacial adhesion between the fabric and the matrix. The surface of the aramid fiber was modified to improve the interfacial properties. The surface of the aramid fibers was treated with ZnCl2 and polydopamine. After the pretreated fabrics were made into a composite material by the vacuum-assisted resin transfer molding (VARTM) process, their mechanical performance was investigated. The highest impact energy was shown in the concentration of 6 wt% ZnCl2 and 1.5 g/L polydopamine, which is 20% better than that of the untreated material. In the bending strength, the condition of 1.5 g/L polydopamine resulted in the highest value and increased by 13% compared to the untreated material. The hybrid surface treatment of ZnCl2 and polydopamine did not significantly affect the tensile strength.

Sb2Se3 Thin-Film Growth by Solution Atomic Layer Deposition

“…We compare thermal SiO 2 -covered Si wafers, piranha-cleaned SiO 2 , TiO 2 -coated substrates, ZnCl 2 -dipped TiO 2 surfaces, amorphous Sb 2 S 3 (ALD-deposited), and crystalline Sb 2 S 3 (after annealing) in Figure a. This list of substrates represents a variety of chemical reactivities: classical oxides on standard Si wafer substrates (SiO 2 ), after standard surface cleaning to remove any organic residues (piranha clean) and for photovoltaic applications (TiO 2 ), oxide activated according to a published procedure to add some surface metal-chloride moieties (ZnCl 2 treatment), , and sulfide surfaces providing typically better adhesion with heavier chalcogenides than oxides (Sb 2 S 3 ). Indeed, the apparent growth rate (calculated from the thickness determined after 50 sALD cycles) varies, Sb 2 Se 3 growing not only fastest but also most reproducibly on the TiO 2 (with or without ZnCl 2 dip) and amorphous Sb 2 S 3 layers.…”

Composites based on polymeric blends reinforced with TiO2 modified aramid fibers

“…Therefore, a series of fiber surface treatment techniques have been developed: ultrasonic treatment, γ-ray irradiation, plasma treatment, etching, cryogenic treatment, and chemical grafting to improve interfacial adhesion strength. [16][17][18] The use of chemical modification techniques leads to significant changes to the surface, but these are difficult to control and can sometimes affect the surface properties of the fiber. Physical modification techniques can lead to a weaker interfacial adhesion than those obtained by chemical methods, also requiring more expensive equipment.…”

“…Therefore, to improve the interfacial connection, different methods of modifying the fiber surface are used, which traditionally favor either physical or chemical adhesion with the matrix. Therefore, a series of fiber surface treatment techniques have been developed: ultrasonic treatment, γ‐ray irradiation, plasma treatment, etching, cryogenic treatment, and chemical grafting to improve interfacial adhesion strength 16–18 . The use of chemical modification techniques leads to significant changes to the surface, but these are difficult to control and can sometimes affect the surface properties of the fiber.…”

Recent advancement in surface modification of aramid fiber assisted by supercritical carbon dioxide

“…Wang and group 29 experiment using the silane coupling method to graft poly(catechol‐polyamine) on the AF skin layer, which enhances pull‐off force from 33 to 60 N and interfacial shear strength from 2.1 to 3.9 MPa. Xu and team 30 applied surface modification of AF rovings by various chemical treatment agents to impose ZnCl 2 and polydopamine on the surface of AF, resulting in a 20% improvise in impact energy, and a 13% improvise in bending strength. Wang et al 31 compared the effectiveness of plasma treatment under low‐pressure plasma with various gases (N 2 , O 2 , and Ar), with different times (5, 10, 15, and 20 min), and at diverse power outputs (100, 200, 300, and 400 W).…”

“…3,28 Wang and group 29 experiment using the silane coupling method to graft poly(catechol-polyamine) on the AF skin layer, which enhances pulloff force from 33 to 60 N and interfacial shear strength from 2.1 to 3.9 MPa. Xu and team 30 applied surface modification of AF rovings by various chemical treatment agents to impose ZnCl 2 and polydopamine on the surface of AF, resulting in a 20% improvise in impact energy, and a 13% improvise in bending strength. Wang et al 31 Apart from that, supercritical carbon dioxide (scCO 2 ) is an effective and upcoming tool for modifying the surface properties of AFs instead of using traditional procedures like the immersion method.…”