Laponite/multigraphene hybrid-reinforced poly(vinyl alcohol) aerogels

Despite significant progress in the area of nanocomposites, laponite/graphene reinforced polymer based composite materials have yet to be investigated. Environmentally-benign combinations of laponite RD (L-RD) and multigraphene platelets (m-Gh) with poly(vinyl alcohol) in the form of aerogels have been demonstrated in the present work, making use of a freeze drying process. The structural characteristics of the aerogels were studied using X-ray diffraction and scanning electron microscopy and correlated to their compressive mechanical properties. The effects of the L-RD:m-Gh ratio on the glass transition temperature and crystallinity of PVA have been investigated using differential scanning calorimetry. The thermal properties of the aerogels have also been evaluated using thermogravimetric analysis. A remarkable synergistic effect between the L-RD and m-Gh platelets in improving the mechanical properties and thermal properties of polyvinyl alcohol aerogel was observed; compared to pure PVA aerogels, an 130% increase in tensile strength and a ∼40% improvement of compressive strength were achieved with the addition of 97:03 of L-RD:m-Gh, which suggests an excellent load transfer between the m-Gh and the L-Rd hybrid nanofillers. The glass transition of PVA increased from 85 to 126 °C with the addition of the L-RD/m-Gh as well. The char yield of PVA aerogels increased monotonically with increasing levels of m-Gh in the composites.