ИСТИНА

The interaction of cationic cylindrical brush (having backbone of DPn(backbone) = 1500 with side-chain of poly([2-(methacryloyloxy)ethyl]trimethylammonium iodide) (PMETAI), grafting density of the side-chain is 50% and DPn(side chain) = 65) with the linear anionic polyelectrolytes, viz., poly(acrylic acid) (PAA(X), DPn = 20, 120 and 500) and poly(sodium styrenesulfonate) (PSSNa(20), DPn = 20), in aqueous media (pH 7, 0.1 M < [NaCl] < 0.5 M) leads to formation of water-soluble interpolyelectrolyte complexes (IPECs) in which PMETAI brush plays a lyophilizing part if the base-molar ratio of the oppositely charged polymeric components Z, Z = [N+]/[COOH + COO-] (the base-molar concentrations of the corresponding polymeric components are given in the brackets) in the system does not exceed a certain threshold values of Z*, Z < Z*. Dynamic light scattering carried out for homogeneous mixtures of PMETAI brush and PAA(X) at Z < Z* provides evidence on monomodal distribution of apparent hydrodynamic radii (Rh(app) = 34 ÷ 38 nm) of the formed macromolecular co-assemblies which is close to hydrodynamic radius (Rh(app) = 33 nm) of the PMETAI brush. Analysis of homogeneous solutions of PMETAI brush and PSSNa(20) by means of analytical ultracentrifugation provides evidence that the macromolecular co-assemblies are considered as particles of the water-soluble IPECs. The interaction of PMETAI brush with double hydrophilic ionic/nonionic diblock copolymer poly(acrylic acid)-block-poly(N-isopropylacrylamide) (PAA(1000)-block-PNIPAM(300), DPn(PAA) = 1000 and DPn(PNIPAM) = 300) in aqueous media at pH 7 and 0.1 M NaCl leads to formation of stable colloidal dispersion even for stoichiometric (Z = 1) mixture of PMETAI brush with PAA(1000)-b-PNIPAM(300). Such mixtures are thermosensitive and increasing of temperature leads to phase separation because PNIPAM is thermosensitive polymer and has lower critical solution temperature.