Investigation of surface properties of poly(Sulfonic Diphenyl Aniline) and its diblock copolymer with poly(Ethylene Glycole) and preparation of organic/inorganic hybrid particles of the diblock copolymer

Poly(sulfonic diphenylaniline) (PSDA) and its diblock copolymer with poly(ethylene glycol), poly(sulfonic diphenylaniline)-block-poly(ethylene glycol) (PSDA-b-PEG) were synthesized and characterized. The zeta potential and hydrodynamic radius of PSDA and PSDA-b-PEG were measured and their SEM/STEM pictures were taken as a function of pH, salt type and concentration since PSDA which is a polyampholyte can bear positive or negative charges due to pH of the solution thus, they can form aggregates sensitive to pH and salt. The zeta potential of the PSDA and PSDA-b-PEG in solutions of pH>1 was found always negative. The hydrodynamic radius of the PSDA in the solutions of pH<1 decreased up to pH=2; and then, it increased in the solutions of 0,1 M NaCl but it decreased in other salt concentrations after this pH. The hydrodynamic radius of the block copolymer in solutions of pH<1 decreased up to pH=1; and then it it did not increase in solutions without salt but increased beyond to 500 nm in the solutions with salt with increasing pH.By inverse gas chromatography (TGK) technique, dispersive surface energy as well as acid, base constants of acidic and neutral PSDA, PSDA-b-PEG as well as calcium carbonate and calcium phosphate as uncoated and coated with the block copolymer was obtained at various temperatures. As the dispersive surface energy of acidic PSDA samples was lower around room temperature, it was increased with temperature. The dispersive surface energy of neutral PSDA samples and block copolymer was same as that of other polymers at room temperature and decreased with temperature as expected. The obtained ratio of acidity and basicity constants of acidic PSDA samples suggested that acidic PSDA sample was acidic and neutral PSDA and block copolymer samples were basic.At several pH and block copolymer concentrations, organic/inorganic hybrid particles of calcium carbonate were synthesized by precipitation from calcium chloride solution including PSDA-b-PEG as a template by means of ammonium carbonate both solution precipitation and gas-liquid diffusion methods. It was observed that the particles obtained by solution precipitation have electrical attractive forces but they do not have specific shapes. The ones obtained by gas-liquid diffusion method have specific shapes affected by pH and block copolymer concentration in the solution. The organic/inorganic hybrid particles of calcium fosfate were synthesized by solution precipitation method from calcium chloride solution including PSDA-b-PEG as a template by means of ammonium phosphate. It was observed that the structure of calcium phosphate particles were strenghten by the block copolymer.