Novolac phenolic resin and graphene aerogel organic-inorganic nanohybrids: High carbon yields by resin modification and its incorporation into aerogel network

Abstract

Graphene oxide (GO) modified with furfuryl alcohol and (3-aminopropyl) triethoxysilane (GOFASi) was used in two separate ways for preparation of novolac resin nanohybrids. In the first procedure, graphene-containing silica aerogel (GA) was obtained by incorporation of GOFASi into silica aerogel network using tetraethyl orthosilicate (TEOS). Then, GA was used as an additive in novolac resin matrix. In the second procedure, the synthesis of a hybrid novolac resin was accomplished by network formation via the reaction of GOFASi with (3

Incorporation of epoxy resin and carbon nanotube into silica/siloxane network for improving thermal properties

“…By the oxidation, modification, and hybrid network formation, the I D /I G value is increased which indicates that modification of CNTOH by HDBTMSPU and also sol-gel process have been carried out successfully [50]. The peaks at 532 and 1072 cm -1 are related to Si-O network [29,30]. Additionally, the peaks appeared at 731 and 941 cm -1 are related to Si-C group [58].…”

“…Accordingly, CNTX shows pore size in the range of 2-100 nm. However, the size of a large number of pores is 2-10 nm, which shows that CNTX can be categorized in mesoporous materials [29,30]. Considering cylindrical pore geometry, pore diameters can be calculated by D = 4V p /S BET , where D is the average pore diameter and V p is the pore volume.…”

“…Noparvar-Qrebagh et al [29] incorporated CNT and novolac resin into silica/siloxane network via sol-gel method by modification of CNT and novolac resin by alkoxysilane modifiers. A similar procedure was employed for incorporation of graphene into novolac matrix by this group [30]. Additionally, Hu and coworkers prepared graphene-reinforced polyurethane hybrids by covalent silica boding between polyurethane and graphene which were already modified with 3-(aminopropyl)triethoxysilane [31].…”

Modification of graphene with silica nanoparticles for use in hybrid network formation from epoxy, novolac, and epoxidized novolac resins by sol-gel method: Investigation of thermal properties

“…These organic-inorganic hybrid materials can be prepared by co-condensation of modified polymers with metal alkoxides and formation of covalent bonding between the organic and inorganic components [16]. In sol-gel methods, hydrolysable alkoxysilanes are commonly used as coupling agents and pH, alkoxide type, water amount, temperature, and drying methods are important factors controlling the hydrolysis and condensation reactions [17][18][19][20]. Uniform distribution of silica/siloxane domains within a polymer matrix in co-condensation process may result in higher thermal and mechanical properties in such hybrid materials.…”

“…They showed that 11.94% increase of char yield was achieved by incorporation of functionalized-CNT in silane-modified novolac resin matrix. A similar method was also used by this group for incorporation of (3-aminopropyl) triethoxysilane (APTES)-modified graphene and (3-glycidyloxypropyl)trimethoxysilane (GPTMS)-modified novolac resin into silica/ siloxane network [19]. They obtained high char value of 70.58% by incorporation of functionalized-graphene layers in silane-modified novolac resin matrix.…”