Reference

Studies on the binding capacity of poly(vinylpyrrolidinone) for bisazo dyes

Studies on the binding capacity of poly(vinylpyrrolidinone) for bisazo dyes. 4. Relations among colloidal association, physical stability, and acute toxicity of bisazo dyes in injectable solutions. Thomas, K.; Steinbach, D. (Inst. Galenische Pharm., Johann Wolfgang Goethe-Univ., Frankfurt/Main, Ger.). Pharm. Ind., 38(9), 841-4 (German) 1976. CODEN: PHINAN. DOCUMENT TYPE: Journal CA Section: 63 (Pharmaceuticals) Bisazo dyes are bound to poly(vinylpyrrolidone) [9003-39-8] in accordance with the Langmuir-Klotz adsorption isotherm. The binding consts. varied from 6700 .times. 10-3/mol for congo red (I) [573-58-0] to 65 .times. 10-3/mole for trypan red [574-64-1], and paralleled the self-assocn. tendencies of the dyes. The degree of binding and of self-assocn. increase with increasing NaCl concn. The results were related to the stabilization of bisazo dyes by poly(vinylpyrrolidone) in solns. for injection.

Electrokinetic properties of polyformaldehyde fibers

Electrokinetic properties of polyformaldehyde fibers. Lokhande, H. T.; Salvi, A. S. (Dep. Chem. Technol., Univ. Bombay, Bombay, India). J. Appl. Polym. Sci., 21(1), 277-90 (English) 1977. CODEN: JAPNAB. DOCUMENT TYPE: Journal CA Section: 39 (Textiles) Evaluation of the electrokinetic properties of polyoxymethylene fibers in the presence of dyes, with or without surfactants and an electrolyte, showed the zeta potential (.zeta.), surface charge d. (.sigma.), and surface cond. (Ks), increased as the concn. of direct dye in the streaming soln. increased. The neg. values of .zeta. were higher for C.I. Direct Blue 1 (I) [2610-05-1] than for C.I. Direct Red 28 (II) [573-58-0] (for equiv. concns. of dye in the streaming soln.) due to the higher basicity of tetrabasic I. The addn. of cationic surfactants decreased .zeta., anionic surfactants increased .zeta., and nonionic surfactants caused a very rapid redn. in .zeta. up to a point when the fiber surface was satd. with surfactant. In the presence of a direct dye and a cationic surfactant, the .zeta. decreased rapidly, describing a hyperbolic curve, and giving a point of inflection. The presence of an electrolyte in the streaming dye soln. progressively lowered .zeta. and increased .sigma.. Ks was dependent on dye, surfactant, and electrolyte concn. but was independent of the nature of the surfactant.