Membrane separation is a field of both industrial and academic importance. Current technology is largely based on polymeric materials, and to a less extent other inorganic materials such as ceramics and metals. While developments in materials properties and membrane structures are constantly evolving, there are two challenges that need to be circumvented for better performance, i.e. the control over the pore structure and the chemical flexibility in modifying pore surface. "Bottom-up" approach to construct composite membranes using nanotubes in polymeric matrix is an effective route in fabricating membranes with well-defined architecture and tunable pore surface chemistry. This dissertation focuses on characterization and evaluation of cyclic peptide nanotubes (CPNs), a natural protein channel mimetic, in constructing sub-nanometer composite membranes with a cylinder-forming block copolymer (BCP) matrix in thin films. The fundamental understanding of the self-assembly of the CPNs from the building blocks establishes the foundation in utilizing the unique feature of CPNs to ensure precise structural control over the dimensions of the 1D nanotubes. The knowledge gained from the co-assembly of CPNs and BCP matrix in thin films allows further processing of the nanotubes to form well-aligned transport channels, establishing the guidelines in fabricating sub-nanometer porous membranes with and without surface chemistry modification. By identifying the key parameters in the membrane fabrication processes, design features for creating high-performance CPN based membranes can be determined and expanded. This indeed provides many exciting opportunities in developing new composite membranes with superior separation performances. The self-assembly of cyclic peptide (CP) subunits forming high aspect ratio nanotubes is driven by strong intermolecular hydrogen bonding. To modulate and tune the growth of CPNs, polymers are conjugated to the exterior of the peptide subunits, resulting in the formation of polymer covered-CPNs (pc-CPNs). Due to the restriction of intermolecular hydrogen bonding, the conjugated polymer chains enter a confined space set by the hydrogen bonding distance. The entropic penalty associated with deforming the conjugated polymers serves as an opposing force destabilizes nanotube structure, while the enthalpic hydrogen bonding drives the nanotube formation. A delicate balance between the enthalpic driving force and the entropic destabilizing force enables one to modulate the growth of the nanotubes. Thus, the dimensions of the resultant pc-CPNs can be supervised simply by regulating the extent of the entropic penalty from the conjugated polymer chains. In co-assembling CPNs and BCP matrix in thin films, both thermodynamic and kinetic parameters are critical to ensure homogeneous thin film morphology with well-aligned CPN channels at the center of the cylindrical microdomains of the BCP oriented normal to the substrate surface. The balance between the enthalpic interactions between the pc-CPNs and BCP and the entropic cost of polymer chain deformation gives rise to only one nanotube in the cylindrical microdomain. Due to the dynamic nature of CPN formation, preaggregation of the nanotubes causes defects of lay-down nanotubes at the membrane surface, hence compromising membrane quality and integrity. As a result, controlling the kinetic pathway of the co-assembly process is vital to fabricate high quality membranes for separation. Two simple approaches targeting two separate aggregation contributors have been developed to effectively prevent preaggregation of CPNs, resulting in high quality membranes suitable for molecular separation. With the advancement in incorporating functional groups to the constituting peptide subunits, the interior surface of the CPNs can be further functionalized. Membranes have been fabricated using both the unmodified and modified CPNs, in which gas separation of CO2/CH4 mixture and hydronium ion transport were performed. In general, the incorporation of the CPNs improves the overall performance of the membranes, likely by providing additional pathways for the permeating molecules. Differences in the separation behaviors of the regular CPNs and the methyl-modified CPNs are observed for both gas separation and hydronium ion transport, where higher selectivity for CO2 over CH4 is seen for the methyl-modified CPNs. The local dipole interactions with CO2 molecules as well as the reduction in pore size are speculated to induce the differences in the performances of unmodified and unmodified CPNs. These studies indeed establish the foundation in fabricating sub-nanometer porous membranes using self-assembled CPNs and BCP matrix in thin films. A delicate balance between the enthalpic and entropic contributions results in precise control over the structures of the nanotubes and the membranes. This unique "bottom-up" strategy demonstrates to be an effective platform in constructing new family of membranes for chemical separations.

An introduction to the state-of-the-art of the diverse self-assembly systems Self-Assembly: From Surfactants to Nanoparticles provides an effective entry for new researchers into this exciting field while also giving the state of the art assessment of the diverse self-assembling systems for those already engaged in this research. Over the last twenty years, self-assembly has emerged as a distinct science/technology field, going well beyond the classical surfactant and block copolymer molecules, and encompassing much larger and complex molecular, biomolecular and nanoparticle systems. Within its ten chapters, each contributed by pioneers of the respective research topics, the book: Discusses the fundamental physical chemical principles that govern the formation and properties of self-assembled systems Describes important experimental techniques to characterize the properties of self-assembled systems, particularly the nature of molecular organization and structure at the nano, meso or micro scales. Provides the first exhaustive accounting of self-assembly derived from various kinds of biomolecules including peptides, DNA and proteins. Outlines methods of synthesis and functionalization of self-assembled nanoparticles and the further self-assembly of the nanoparticles into one, two or three dimensional materials. Explores numerous potential applications of self-assembled structures including nanomedicine applications of drug delivery, imaging, molecular diagnostics and theranostics, and design of materials to specification such as smart responsive materials and self-healing materials. Highlights the unifying as well as contrasting features of self-assembly, as we move from surfactant molecules to nanoparticles. Written for students and academic and industrial scientists and engineers, by pioneers of the research field, Self-Assembly: From Surfactants to Nanoparticles is a comprehensive resource on diverse self-assembly systems, that is simultaneously introductory as well as the state of the art.

Emphasizing four major classes of polymers for drug delivery-water-soluble polymers, hydrogels, biodegradable polymers, and polymer assemblies-this reference surveys efforts to adapt, modify, and tailor polymers for challenging molecules such as poorly water-soluble compounds, peptides/proteins, and plasmid DNA.

The term biomimetic is comparatively new on the chemical scene, but the concept has been utilized by chemists for many years. Furthermore, the basic idea of making a synthetic material that can imitate the func tions of natural materials probably could be traced back into antiquity. From the dawn of creation, people have probably attempted to duplicate or modify the activities of the natural world. (One can even find allusions to these attempts in the Bible; e. g. , Genesis 30. ) The term "mimetic" means to imitate or mimic. The word "mimic" means to copy closely, or to imitate accurately. Biomimetic, which has not yet entered most dictionaries, means to imitate or mimic some specific bio logical function. Usually, the objective of biomimetics is to form some useful material without the need of utilizing living systems. In a simi lar manner, the term biomimetic polymers means creating synthetic poly mers which imitate the activity of natural bioactive polymers. This is a major advance in polymer chemistry because the natural bioactive polymers are the basis of life itself. Thus, biomimetic polymers imitate the life process in many ways. This present volume delineates some of the recent progress being made in this vast field of biomimetic polymers. Chemists have been making biomimetic polymers for more than fifty years, although this term wasn't used in the early investigations.

Polymers are essential to biology because they can have enough stable degrees of freedom to store the molecular code of heredity and to express the sequences needed to manufacture new molecules. Through these they perform or control virtually every function in life. Although some biopolymers are created and spend their entire career in the relatively large free space inside cells or organelles, many biopolymers must migrate through a narrow passageway to get to their targeted destination. This suggests the questions: How does confining a polymer affect its behavior and function? What does that tell us about the interactions between the monomers that comprise the polymer and the molecules that confine it? Can we design and build devices that mimic the functions of these nanoscale systems? The NATO Advanced Research Workshop brought together for four days in Bikal, Hungary over forty experts in experimental and theoretical biophysics, molecular biology, biophysical chemistry, and biochemistry interested in these questions. Their papers collected in this book provide insight on biological processes involving confinement and form a basis for new biotechnological applications using polymers. In his paper Edmund DiMarzio asks: What is so special about polymers? Why are polymers so prevalent in living things? The chemist says the reason is that a protein made of N amino acids can have any of 20 different kinds at each position along the chain, resulting in 20 N different polymers, and that the complexity of life lies in this variety.

Polymers have played a critical role in the rational design and application of drug delivery systems that increase the efficacy and reduce the toxicity of new and conventional therapeutics. Beginning with an introduction to the fundamentals of drug delivery, Engineering Polymer Systems for Improved Drug Delivery explores traditional drug delivery techniques as well as emerging advanced drug delivery techniques. By reviewing many types of polymeric drug delivery systems, and including key points, worked examples and homework problems, this book will serve as a guide to for specialists and non-specialists as well as a graduate level text for drug delivery courses.

This third edition volume expands on the previous editions with updated approaches and techniques used to study protein nanotechnology and the future of nanomaterial compositions. This book is organized into Three Parts: Part One looks at recombinant protein expression in insect cells, and methods to produce molecular motors, molecular superglues, and protein templates; Part Two explores functionalization strategies and ways to incorporate functional protein components into nanodevices; Part Three discusses various instrumental techniques used to study protein nanostructures. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Cutting-edge and thorough, Protein Nanotechnology: Protocols, Instrumentation, and Applications, Third Edition is a valuable resource for any researchers looking to expand their knowledge in this evolving field.