Please solve 1, 2, 3, 4 and 5

1. The characteristics of swollen and collapsed states of smart polymers as a function of temperature allow many potential applications such as drug delivery. Other applications include protective coatings and cathodic protection systems. Explain one possible functional system that allows one of these applications. 2. At equilibrium, different types of hydrogel polymers have a characteristic swelling degree and specific LCST. Explain how hydrophobic and hydrophilic interactions inside a hydrogel chain would affect the LCST. 3. Describe engineered drug delivery systems that can be either positive or negative thermosensitive drug release. 4. At room temperature, gelatin is a hydrogel. Explain why upon heating it is a solution. 5. For most polymers entropy favors mixing but enthalpy disfavors mixing, however for hydrogels entropy disfavors mixing but enthalpy favors mixing. Explain. AG = AH-TAS