Water-soluble polymers of varying types have been extensively studied because they have been widely used in adhesive, textile, medical, dispersing agents, and other related industries. The solubilities, moisture regain properties, and solution properties of the polybetaines and cationic polymers are investigated in relation to their molecular structures. Because the cationic polymers were ionized in an aqueous solution, the cationic polymers were more soluble than the polybetaine. For the various functional groups of polybetaines and cationic polymers, the order of tendency for moisture regain is -COO- >-CONH-. The macroscopic solution properties of water-soluble polymers are examined in this study by measuring reduced viscosity, intrinsic viscosity, degree of binding, and dynamic light scattering. The intrinsic viscosity is related to the type and concentration of the salt added. The intrinsic viscosity behavior for the polybetaine resulting from the associations of the polymer chains is in contrast with cationic and anionic polyelectrolyte. The polybetaine in high concentration of NaCI has a low degree of binding indicating that the proton ion (H⁺) has difficulty in binding to the anionic group at the polymer end. The carboxybetaine has a higher degree of binding than the corresponding sulfobetaine. When fluorescent hydrophobes (naphthyl group) are incorporated into the cationic copolymer, the photophysical response may effectively probe solution behavior on the microscopic level. The salt and Ph responsiveness inherent to the cationic copolymer systems is a function of ionic group type. Experimental results indicate that l_E/I_M increases steadily with increases in polymer concentration and I_E/I_M values for a given polymer concentration are higher in salt. Dynamic light scattering (QELS) measurements indicate that diffusion coefficients of the cationic copolymer increase and the hydrodynamic diameters decrease with increasing salt concentration. In contrast, the diffusion coefficients of the polybetaine decrease and the chain dimensions increase with an increasing salt concentration. In fluorescence quenching study, the reduction in the quenching efficiency of thallium (IT⁺) with salt addition can arise from enhanced compartmentalization of naphthalene labels as added electrolyte enhances intra-polymer micellization. The intra-polymer micelle is easily formed, indicating that the thallium ion has difficulty in reacting with bound naphthalenes located in the shrunk polymer coil. The cationic polymer is depicted as an expanded polymer coil in deionized water because of intra- and inter- chain repulsious. Consequently, salt addition breaks down the repulsions and enhances intra-polymer micellization. The corresponding polybetaines shows contrast behavior. Surface modifications of polymer films have been carried out via thermally and/or photo-chemically induced graft copolymerization with water-soluble polymer, acrylic acid, sodium salt of styrenesulfonic acid, N-N`-dimethyl(methacryloylethyl) ammonium propanesulfonate, and acrylamide. The structure and chemical composition of each graft-copolymerized surface were studied by angle-resolved X-ray photoelectron spectroscopy (XPS). In all cases, the concentration of grafting increases with monomer concentration. Surface grafting with the functional water-soluble monomers also leads to a more hydrophilic polymer film surface. Two graft-copolymerized polymer film surfaces are capable of exhibiting adhesive-free adhesion when brought ulto direct contact in the presence of water and subsequently dried. The development of the lap shear adhesion strength depends on the concentration of the surface graft, the adhesion (drying) time, the physical property substrate, the microstructure grafted surfaces, and the nature of the molecular interaction (dispersive, ionic, etc.) at the junction.