Preparation and characterization of anionic collagen: P(VDF/TrFE) composites

Anionic collagen:P(VDF/TrFE) (75/25) membrane composites were prepared by m ixing anionic collagen and P(VDF/TrFE) in aqueous concentrated acetic acid: dimethylsulfoxide solutions and characterized by infrared, electron scannin g microscopy, thermal analysis and dielectric properties, The results show that under the appropriate conditions anionic collagen:P(VDF/TrFE) composit es, with ratios in the range from 4:1 to 1:4 may be conveniently prepared i n the form of membranes, without the loss of tropocollagen secondary struct ure. As suggested by infrared spectroscopy and thermal analysis, mixing is accompanied by macromolecular interaction conditions anionic collagen and P (VDF/TrFE). Although preliminary, the determined pyroelectric coefficient f or the 1:1 composite of 1.89 x 10(-4)Cm(-2)K(-1), is higher than those dete rmined under the same conditions for native, anionic collagen and P(VDF/TrF E) and of respectively 0.37 x 10(-4)Cm(-2)K(-1), 1.16 x 10(-4)Cm(-2) K-1 an d 17 x 10(-6) Cm-2K-1, but comparable to that for PZT (4.2 x 10(-4)Cm(-2)K( -1)) at the same temperature. This increase in pyroelectric coefficient for the 1:1 composite, in respect to anionic collagen membranes, may be a resu lt of a anionic collagen: P(VDF/TrFE) interaction. A model based on hydroge n bonding formation between acidic and alcoholic hydroxyl groups of anionic collagen and the fluorine atoms of P(VDF/TrFE) is proposed.