抄録
Nanocomposite gels were prepared by mixing clays with gelatin. The clay was either of plate-like (montmorillonite, laponite) or fibrous morphology (sepiolite). The dispersion of the clay was monitored by X-ray diffraction and the gel structure was scrutinized by low temperature scanning electron microscopy. The mechanical properties of the gels were investigated by conventional dynamic mode rheological measurements in stress-imposed mode. The results show that plate-like particles (montmorillonite, laponite) are extremely effective for increasing the gel formation temperature, whereas fibrous particles are not. A correlation was found between the gel formation temperature and the cell size of the gel, as observed by cryo-SEM. Surprisingly, in spite of the strong smectite-induced shift of the gelation temperature, the mechanical properties of the gel were unaffected, in the investigated concentration range. Thin (a few tens of micrometers) self-standing and well transparent films are easily obtained by drying. These organic-inorganic hybrid gels and films are attractive materials for several applications, including biomedical treatments and conservation of antique wall paintings.
