New high-effective flocculants containing triblock copolymers PAA-b-PEO-b-PAA (TBC) based on chemically-complementary polyacrylamide (PAA) and poly(ethylene oxide) (PEO) with the different block lengths are synthesized, characterized, tested and patented in Ukraine. Given TBCs, which are obtained by free radical block copolymerization of acrylamide with poly(ethylene glycols) of different molecular weight, are intramolecular polycomplexes (IntraPCs) with a strong interacting polymer components. It was revealed that the block copolymerization process has a matrix character because non-covalent interactions of growing PAA chains with PEO. High flocculate ability of TBC in clearing of kaolin suspensions and natural water was established.