Biomedical subjects

Hany B Eitouni

Publications and source records attributed to Hany B Eitouni.

3 recordsLinked to original sources

PubMed2006

Electrochemically controlled self-assembly of an organometallic block copolymer.

A new means of controlling the order-disorder transition of block copolymers is presented. By applying small electrical potentials (2 V/cm) to disordered solutions of an organometallic block copolymer, oriented ordered grains were obtained near the positive electrode. After reversing the electrical bias on the system, the ordered grains disappeared, and new, oriented, ordered regions were formed at the opposite electrode. Our work establishes the concept of electrochemical self-assembly for controlling order formation in block copolymers.

Journal Article↗

PubMed2004

Effect of chemical oxidation on the self-assembly of organometallic block copolymers.

The thermodynamic interactions in poly(styrene-block-ferrocenyldimethylsilane) and poly(isoprene-block-ferrocenyldimethylsilane) copolymers were systematically tuned by oxidation of the ferrocene moieties with silver nitrate. Small-angle X-ray scattering experiments show that oxidizing 8% of the ferrocene moieties lowers the order-disorder transition temperature of the copolymers by as much as 40 degrees C.

Butadienes↗

PubMed2003

Responsive solids from cross-linked block copolymers.

Novel responsive solids were prepared by randomly cross-linking the polyisoprene chains of a disordered polystyrene-polyisoprene block copolymer. Our experiments show that block copolymer chains, composed of hundreds of repeat units, can undergo reversible order-disorder transitions despite the quenched randomness that arises due to the attachment of one of the blocks to a cross-linked network. The structure, properties, and phase behavior of these materials are determined by a delicate interplay between the density of cross-links and the nature of the ordered state.

Journal Article↗