A technique for studying polymer interactions with concentration gradients using light scattering and viscometry
Description
Light scattering together with viscometry and chromatography techniques are used to examine polymers and their interactions with various substances such as salts and surfactants. New and improved upon techniques provide detailed results which have never been possible before. One such technique is developed which uses a programmable mixer to study interactions of polymers over a wide range of concentrations. It is referred to as the automatic continuous mixing technique or simply ACM. This technique has led to detailed studies of virial coefficients and the radius of gyration of polyelectrolytes with several different salts. These studies have led to verification of several theoretical models in which the computations match the experimental results. One such significant finding is the relationship between A 2 and A3. It was predicted assuming the polymers to be spheres that the relationship be A3 ∝ A22 . This remarkable relationship was seen in the experimental results for Hyaluronate in NaCl. This technique was also used to study a variety of different interactions such as surfactants and polymers, zwitterion polymers and salts as well as more complex systems of proteins and denaturing agents. Light scattering is also implemented in the HTDSLS which is heterogeneous time dependent static light scattering and ACOMP automatic continuous on-line monitoring of polymerization reactions. HTDSLS enables one to monitor simultaneously a polymer solution contaminated with larger particles provided certain conditions are meant. The technique was used to observe the simultaneous growth of virus (polymer) and bacteria (large particle). The ACOMP technique which has been successfully implemented for a variety of polymerizations is used here to monitor several different types of polymerizations simple radical growth. ATRP (atom transfer radical polymerization) as well as the step growth of polyamine. All of these utilizations of light scattering have significant applications to industry. In example heterogeneous systems such as those seen in the pharmaceutical industries can be monitored using HTDSLS. ACOMP can be used to control polymerizations in order to avoid waste while ACM can be used in the characterization and study of interactions relevant to various industries. All of these techniques are also beneficial to the discoveries of basic scientific importance