Stimuli‐responsive polymer hydrogels containing partially exfoliated graphite

Abstract

In this work, a new stimuli‐responsive composite polymer hydrogel containing partially exfoliated graphite was prepared by frontal polymerization. The materials obtained were characterized by differential scanning calorimetry, RAMAN, scan electron microscopy, transmission electron microscopy, atomic force microscopy, and in terms of swelling behavior. It was found that the maximum temperature reached by the polymerization front and the lower critical solution temperature are affected by the graphite content. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010

A review of exfoliated graphite

“…The incorporation of GNP in polycarbonate is associated with a percolation threshold of 4.0 vol% [99]; at 5 vol% GNP (above the threshold), the electrical resistivity remains high at 4.0 9 10 7 X cm and the thermal conductivity remains low at 0.37 W/(m K) [99]. The incorporation of GNP in a polymer hydrogel is potentially attractive for improving the ability of the hydrogel to respond to stimuli [100].…”

Preparation of poly(acrylic acid)–graphite oxide superabsorbent nanocomposites

“…Under an inert atmosphere, MBA (16 mg) was added into the AA-GO mixture solution with vigorous stirring at room temperature. 15 min later, the mixture solution was heated to [30][31][32][33][34][35] C and then radical initiator APS (80 mg) was quickly added into the mixed solution. As the temperature was slowly increasing, the mixture became a brown jelly at 50-55 C. The reaction was maintained at 70 C for 3 h, then 12 mL of sodium hydroxide solution (3 mol L À1 ) was added into the reaction vessel and the system was kept at 70 C for 1 h. The resulting product (named as PAA-GO1, with a GO content of 0.037 wt%) was washed several times with distilled water, dried in a vacuum oven at 60 C to a constant weight, and then milled and screened with a particle size in the range of 60-80 mesh.…”

“…In these cases, emphases were laid on the improvement of the thermal, mechanical or electrical properties of the resulting GO-polymers-based nanocomposites. Moreover, though recently there have been a few reports of GO or graphene-based hydrogels, [29][30][31][32] no study involving the preparation of superabsorbent nanocomposites employing GO as nanofillers or the investigation of their swelling performance has been reported so far. In a continuation of our studies on absorbent materials, 10,11,33 here we report the preparation of GO-based superabsorbent nanocomposites via a facile solution polymerization of acrylic acid (AA) monomers, using N,N 0 -methylenebisacrylamide (MBA) as cross-linker, ammonium persulfate (APS) as initiator and GO nanoplatelets as nanofillers.…”

Preparation and interaction study between fullerene and graphene in a polymeric matrix

“…Graphene, a monolayer of sp 2 hybridized carbon atoms bonded in a hexagonal lattice, is formally the parent of all the graphitic carbon forms [1,[3][4][5]. Our research group improved a method to obtain graphene initially proposed by Hernandez et al [6] that involves the use of ultrasounds in order to exfoliate graphite, without any chemical manipulation and without using graphite oxide [7][8][9][10][11][12], which generally results in considerable damaging of the graphene electronic structure [13]. In addition, in order to synthesize polymeric nanocomposites containing graphene, our research group obtained graphene directly in the monomer [12][13][14] thus allowing for the direct, in situ polymerization of the graphene/monomer dispersion.…”