Chitosan-calcium carbonate composites by a biomimetic process

Formation of thin calcium carbonate films with aragonite and vaterite forms coexisting with polyacrylic acids and chitosan membranes

“…These observations show that -COO − and -NH + 3 coexist on the surface of the chitosan membranes in the presence of PAA. This result agrees with the result obtained by Zhang and Gonsalves [12,13]. The IR spectra of the precipitates obtained from the CaCl 2 solution containing 2.00 mg PAA (5 ml, pH 3.6) without the chitosan membrane showed the asymmetrical and symmetrical stretching modes of the -COO − groups that appeared at 1557 and 1421 cm −1 , respectively.…”

“…Recently, Zhang and Gonsalves [12,13] and Kato and co-workers [14,15] studied the crystallization of CaCO 3 on a chitosan membrane using a supersaturated CaCO 3 solution with PAA, and they succeeded in the formation of thin CaCO 3 films and showed that the cooperative effect of a chitosan membrane and PAA caused the local high concentration of Ca 2+ ions around the chitosan membrane. In addition, Zhang and Gonsalves indicated that (a) the nucleation of CaCO 3 was initiated from the protonated nitrogen and carboxylate anions that were produced on the chitosan membrane surface by introducing PAA into a supersaturated CaCO 3 solution and (b) calcite crystals with orientation formed by epitaxial growth [12,13]. On the other hand, Kato and co-workers indicated that (a) PAA was adsorbed onto a chitosan membrane by hydrogen bonds between the COO − moieties of PAA and OH or NH groups of the chitosan membrane and these bonds resulted in the strong binding of Ca 2+ ions, and (b) vaterite crystals predominantly formed in accordance with Ostwald's rule [14,15].…”

“…The use of organic molecules such as collagen [7], cholesterol [8], a stearic acid monolayer [9], chitin [11], and polyacrylic acid [12][13][14][15] showed significant effects on the synthesis of a polymerCaCO 3 composite. Recently, Zhang and Gonsalves [12,13] and Kato and co-workers [14,15] studied the crystallization of CaCO 3 on a chitosan membrane using a supersaturated CaCO 3 solution with PAA, and they succeeded in the formation of thin CaCO 3 films and showed that the cooperative effect of a chitosan membrane and PAA caused the local high concentration of Ca 2+ ions around the chitosan membrane. In addition, Zhang and Gonsalves indicated that (a) the nucleation of CaCO 3 was initiated from the protonated nitrogen and carboxylate anions that were produced on the chitosan membrane surface by introducing PAA into a supersaturated CaCO 3 solution and (b) calcite crystals with orientation formed by epitaxial growth [12,13].…”

Polymorph Farming of Acetaminophen and Sulfathiazole on a Chip

“…PE-Chl is a polymer reported to be capable of inducing the thermodynamically unstable Form II needles of acetaminophen in water by evaporation (10). Chitosan is a polysaccharide of many applications in pharmaceutical system as a drug carrier (26), biomimetic process (27) and optical wave guide (28). …”

Biomimetic Calcium Carbonate in the Carboxymethyl Chitosan /Bovine Serum Albumin System

“…One aim is to gain further knowledge about basic principles of biomineralization and the second is to use this knowledge for biomimetic processing of biomaterials, with applications envisaged in bone tissue engineering especially 9 . Formation of CaCO 3 films on the surface of chitosan membranes has been studied by some researches [10][11][12][13][14] . We chose carboxymethyl chitosan and bovine serum albumin as matrices because they can be considered synthetic analogues of insoluble and soluble matrices in nacre, respectively.…”