Some polymers may respond by changing their physico-chemical perperties when the environmental conditions such as pH, temperature and ionic strength are varied. For example, thermosensentive polymers can exhibit a sharp change in solubility in a solvent s Some polymers may respond by changing their physico-chemical perperties when the environmental conditions such as pH, temperature and ionic strength are varied. For example, thermosensentive polymers can exhibit a sharp change in solubility in a solvent s