A method of preparation of ultrallne CaCO3 particles in ordered systems, as in vesicle and Ancroemulsion, consisting of egg yolk phospholipid and water has been introduced. The size of CaCO3 grain was controlled by th...A method of preparation of ultrallne CaCO3 particles in ordered systems, as in vesicle and Ancroemulsion, consisting of egg yolk phospholipid and water has been introduced. The size of CaCO3 grain was controlled by the content of egg yolk phospholipid and size of liposoms in the systems. It was found by experiment that vaterite is formed inside the doublle layer vesicles but caJcite is formed outside of the vesicles. A discussed of the cause of this difference has been giYen.展开更多
Influence of the concentration of phosphatidylcholine (PC) in the solution of 0.5mol.L-1 CaCl2 on the crystal structure of CaCO3 has been studied by means of X-ray diffeaction method.When the concentration of PC is be...Influence of the concentration of phosphatidylcholine (PC) in the solution of 0.5mol.L-1 CaCl2 on the crystal structure of CaCO3 has been studied by means of X-ray diffeaction method.When the concentration of PC is below its CMC, the calcite CaCO3 is formed. It advantageous that CaCl2 reacts with Na2CO3 so as to form vaterite CaCO3 in the lipesome composed of PC more than in the water. The arnount of vaterite CaCO3 formed is increased with increase of con-centration of PC. But if the concentration of PC is so increased as to form liquid crystal, then the amount of vaterite decreases obviously. The reason for the difference of crystal type formed has been discussed in the paper.展开更多
The fractal dimensions (df) of aggregates of latex paticles coated by poly(ethylene oxide)(PEO) have been measuxed in worse than θ-solvents for different concentrations MgSO4 and temperatures by means of dynamic ligh...The fractal dimensions (df) of aggregates of latex paticles coated by poly(ethylene oxide)(PEO) have been measuxed in worse than θ-solvents for different concentrations MgSO4 and temperatures by means of dynamic light scattering. For the lowest molar mass PEO studied (20kg·mol-1) the measurement df of about 2.1 was almost independent of temperature over the range studied. The value corresponds to partially reyersible cluster aggregation, which leads to relatively compact aggregates. For the highest molar mass PEO studied (600kg·mol-1), the df decreased significantly (from 2.4 to 1.7) with temperature, singnifying the generation of more ramified aggregates. The results obtained for this hydrophilic polymer contrast makedly with the aggregation of latexes stabilized by the hydrophobic polymer poly(N-isopropylacryldride)(PNIPAM) which undergoes a coil-to-globule transition.展开更多
Zeta potential of PC and PC-Cholesterol liposome was measured by microelectrophoretic mobility in the presence of different types of electrolyte. A combination of GouyChapman-Stern theory and Poisson-Boltzmann equatio...Zeta potential of PC and PC-Cholesterol liposome was measured by microelectrophoretic mobility in the presence of different types of electrolyte. A combination of GouyChapman-Stern theory and Poisson-Boltzmann equation was used to describe the regularity of the dependence of Zeta potential on several cations and anions with different valencies. Interaction mechanism of cation, anion and cholesterol with PC polar head group was discussed. The electrostatic force is dominated in influencing the surface potential of liposome.展开更多
文摘A method of preparation of ultrallne CaCO3 particles in ordered systems, as in vesicle and Ancroemulsion, consisting of egg yolk phospholipid and water has been introduced. The size of CaCO3 grain was controlled by the content of egg yolk phospholipid and size of liposoms in the systems. It was found by experiment that vaterite is formed inside the doublle layer vesicles but caJcite is formed outside of the vesicles. A discussed of the cause of this difference has been giYen.
文摘Influence of the concentration of phosphatidylcholine (PC) in the solution of 0.5mol.L-1 CaCl2 on the crystal structure of CaCO3 has been studied by means of X-ray diffeaction method.When the concentration of PC is below its CMC, the calcite CaCO3 is formed. It advantageous that CaCl2 reacts with Na2CO3 so as to form vaterite CaCO3 in the lipesome composed of PC more than in the water. The arnount of vaterite CaCO3 formed is increased with increase of con-centration of PC. But if the concentration of PC is so increased as to form liquid crystal, then the amount of vaterite decreases obviously. The reason for the difference of crystal type formed has been discussed in the paper.
文摘The fractal dimensions (df) of aggregates of latex paticles coated by poly(ethylene oxide)(PEO) have been measuxed in worse than θ-solvents for different concentrations MgSO4 and temperatures by means of dynamic light scattering. For the lowest molar mass PEO studied (20kg·mol-1) the measurement df of about 2.1 was almost independent of temperature over the range studied. The value corresponds to partially reyersible cluster aggregation, which leads to relatively compact aggregates. For the highest molar mass PEO studied (600kg·mol-1), the df decreased significantly (from 2.4 to 1.7) with temperature, singnifying the generation of more ramified aggregates. The results obtained for this hydrophilic polymer contrast makedly with the aggregation of latexes stabilized by the hydrophobic polymer poly(N-isopropylacryldride)(PNIPAM) which undergoes a coil-to-globule transition.
文摘Zeta potential of PC and PC-Cholesterol liposome was measured by microelectrophoretic mobility in the presence of different types of electrolyte. A combination of GouyChapman-Stern theory and Poisson-Boltzmann equation was used to describe the regularity of the dependence of Zeta potential on several cations and anions with different valencies. Interaction mechanism of cation, anion and cholesterol with PC polar head group was discussed. The electrostatic force is dominated in influencing the surface potential of liposome.
