Self-Standing Thick Films

Self-standing polyimide films with thicknesses ranging between 25 and 150 xm are commercially available either as nonoriented amorphous materials primarily used as adhesives or oriented films with... 

The CHCl3/Et0H/H20 (4 1 0.07) solution of the DNA-lipid complex (0.25 g) was cast on a Teflon plate and the solvent was evaporated slowly under the saturated vapor at room temperature. The obtained self-standing film was (ca. 60 xm thick) water-insoluble, and physically stable (Fig. 6a). The DNA film can be obtained also from the hot-press method. Here, the powder of the DNA-lipid complex was hot-pressed at 120 °C for 1 min under... 

For the preparation of membranes based on HBPI or LPI or HBPI and silicaa solution of either HBPAA or LPAA or a suspension of silica in HBPAA solution were spread onto a glass substrate (treated with chlorotrimethylsilane). The resulting thin layer was kept at 60 °C for 12 h, 100 °C for Ih, 150 °C for 1 h, 200 °C for 2 h and 250 °C for 1 h. The thickness of the self-standing films obtained was about 50-100 pm. 

Thermal expansion coefficients are determined by thermomechanical analysis using a dilatation-penetration probe for adhesive pastes and an extension probe for self-standing films. The output of the thermal analyzer equipped with a dilatation probe is a curve plotting the variation of adhesive thickness as a function of the temperature. 

While the growth of poly(A/-p-nitrophenylpyrrole) films is self-limiting, stopping at 200-300 nm, thick and free-standing films of the copolymer with pyrrole can... 

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