Enhanced physical properties of γ-Al₂O₃–rGO hybrids prepared by solvothermal and hot-press processing

Abstract

aIn this study, a solvothermal method was employed for the first time to fabricate hybrids composed of crosslinked g-Al 2 O 3 nanorods and reduced graphite oxide (rGO) platelets. After calcination and hot-press processing, monoliths of Al 2 O 3 -rGO hybrids were obtained with improved physical properties. It was found that the oxygen-containing groups on graphene oxide were beneficial for the adsorption of aluminum isopropoxide, leading to a uniform dispersion of rGO with Al 2 O 3 , which was obtained by hydrolysis of aluminum isopropoxide during the solvothermal reaction. The hybrid, which was subsequently calcinated for 3 h showed electrical conductivity of 6.7 Â 10 1 S m À1 together with 90%higher mechanical tensile strength and 80% higher thermal conductivity as compared to the bare Al 2 O 3 . In addition, the dielectric constant of the hybrid was 12 times higher than that of the bare Al 2 O 3 . In this study, the highest values of electrical conductivity (8. 10 4 ) and Young's modulus (3.7 GPa) were obtained for the alumina-rGO hybrid calcinated for 1 h. XRD characterization showed that an increase in calcination temperature and further hot-press processing at 900 C led to enhanced crystallinity in the g-Al 2 O 3 nanorods in the hybrid, resulting in enhanced physical properties in the hybrids.

Sonochemical synthesis of aluminium and aluminium hybrids for remediation of toxic metals

“…It is assumed that attachment of indole group provides the additional surface area which facilitates the adsorption process. A similar trend was also observed by other researchers [38] , [39] . The nitrogen adsorption–desorption isotherm showed adsorption type-III and IV by non-sonicated and sonicated aluminium hybrids.…”

A Review on Development of Ceramic-Graphene Based Nanohybrid Composite Systems in Biological Applications

“…Other works concerned a newly developed solvothermal method, which was employed for the first time to fabricate RGO/Al 2 O 3 nanocomposite in a form of Al 2 O 3 nanorods covering the GO surface ( Ikram et al, 2018 ). Further reduction of GO to RGO was obtained by further calcination treatment, which was followed by hot pressing to obtain hybrid samples.…”

Surface Science of Graphene-Based Monoliths and Their Electrical, Mechanical, and Energy Applications

“…Low strength and brittle attributes are the main properties of ceramics. The most widely used structural ceramic is alumina, due to its good thermal conductivity and the shape stability [7]. Alumina has a wide range of applications, some of the fields include dental implants, high speed cutting tools, chemical insulators, electrical insulators, and wear resistant coatings.…”

“…Moreover, scientists have found that in a microwave preparation of alumina-rGO composites, the grain size of the alumina matrix was reduced from 475 to 180 nm, which was obtained from the conventional sintering process, leading to an increase in the Young's modulus from 148 to 180 GPa. Scientists have found that using solvothermal-hot press processing route, highly conductive alumina-rGO hybrids may be obtained, which consist of Al 2 O 3 nanorods and rGO, respectively [7,8,10]. The same solvothermal method was used to form hybrids from cross-linked Al 2 O 3 nanorods and reduced graphite oxide (rGO) platelets.…”

“…Decades ago, scientists believed that carbon comes in two basic forms, that is, graphite and diamond, but in the last three decades, scientists have discovered new forms of carbon known as advanced carbon materials including fullerene, carbon nanotubes (CNTS), and graphene, respectively [1][2][3][4][5][6]. In recent years, graphene is considered as an outstanding candidate for enhancing the structural, electrical, mechanical, and thermal properties of materials (for example, metals, ceramics, and polymers) [7,8]. In hybrid nanostructures, the physical property enhancement may be possible due to excellent physical properties of the graphene.…”