New nanophase separated intelligent amphiphilic conetworks and gels

Amphiphilic conetworks (APCN) are new materials composed of covalently bonded otherwise immiscible hydrophilic and hydrophobic polymer chains. The amphiphilic nature of these new crosslinked polymers is indicated by their swelling ability in both hydrophilic and hydrophobic solvents. Special synthetic techniques have been developed for the preparation of these new unique materials, such as poly(2-hydroxyethyl methacrylate)-l-polyisobutylene (PHEMA-1-PIB), poly(methacrylic acid)-l-polyisobutylene (PMAA-1-PIB) and poly(N,N-dimethylaminoethyl methacrylate)-l-polyisobutylene (PDMAEMA-l-PIB) (-l- stands for linked by). Due to their unique architecture, macrophase separation of the immiscible components is prevented by the chemical bonding in the conetworks. As a results, phase separation leads to nanodomains with usually 2-20 nm domain sizes as shown by AFM measurements. The nanophase separated morphology may also lead to smart temperature responsive gels with high mechanical stability, such as in the case of poly(N,N-dimethylaminoethyl methacrylate)-l-polyisobutylene APCNs as discovered during these studies. In another approach, poly(2-hydroxyethyl methacrylate)-l-polyisobutylene and poly(methacrylic acid)-l-polyisobutylene APCNs were prepared by a special two-step process. The new PMAA-1-PIB polyelectrolyte APCNs possess smart (intelligent) reversible pH-responsive properties in aqueous media. These unique conetwork structures and proper-ties of these new emerging materials may lead to numerous new potential applications, such as smart materialk products, sustained drug release matrices, biomaterials, nanohybrids, nanotemplates etc.