MSE Colloquium: Dr. Paschalis Alexandridis, Block Copolymer Organization in Solvents: Fundamentals and Applications in Drug Delivery and Nanomaterials Synthesis

Abstract

Soft materials, also known as complex fluids, present diverse and interesting properties and function which emanate from the nano- and meso-scale organization of constituents such as polymers, particles and solvents. Polymers, in particular, copolymers comprising covalently-linked blocks of different chemical nature or conformation are prime examples of tunable materials that are amenable to rational design. Selective solvents may disrupt certain types of polymer organization but can promote others; they also enhance the local mobility. Added solvents thus provide valuable degrees of freedom for controlling the morphology and structure/property relationships of polymers. The incorporation of “hard” nanoparticles into a “soft” matrix can modify dramatically the structure and dynamics, and also confer novel properties (optical, electrical, catalytic) to the composite material.

The presentation will highlight the interplay between (A) fundamental aspects (interactions, thermodynamics, phase behavior, structure, dynamics) of soft materials based on block copolymer organization in selective solvent media, and (B) applications of such self-assembled systems in the (i) structuring of waterborne complex fluids with properties tailored for drug delivery and (ii) environmentally benign synthesis of nanoparticles in a size- and shape-controlled manner. Specific examples will be utilized from our research on block copolymers of the poly(ethylene oxide)-block-poly(propylene oxide) (PEO-PPO) family, commercially available as Poloxamers or Pluronics and approved for pharmaceutical use.

Bio

Paschalis Alexandridis is Distinguished Professor in the Department of Chemical and Biological Engineering (CBE), University at Buffalo, The State University of New York (SUNY), where he has served as CBE Director of Graduate Studies, co-Director of the Materials Science and Engineering program, and Associate Dean for Research and Graduate Education in the School of Engineering. He has a PhD in chemical engineering from MIT and has carried out postdoctoral research in physical chemistry at Lund University. Alexandridis' research utilizes molecular interactions and supramolecular assemblies to develop products with desired properties and function, and processes that are environment friendly and energy efficient. Ongoing projects address self-assembly and directed assembly of block copolymers, perfluorinated surfactant removal/replacement, ionic liquid solvents, biomass dissolution, and plastics recycling. He has authored over 165 journal articles (Web of Science citations >17,700; h-index = 60) and 6 US patents on pharmaceutical formulations, superabsorbent polymers, and nanomaterial synthesis. Alexandridis is a Fellow of the American Association for the Advancement of Science (AAAS) and the American Institute of Chemical Engineers (AIChE), and has served as chair of AIChE Area 1C: "Interfacial Phenomena" and on the executive committee of the American Chemical Society (ACS) Division of Colloid and Surface Chemistry. (http://www.cbe.buffalo.edu/alexandridis)