Large quantities of biosolids are produced from treatment of municipal wastewater and can be processed into a nutrient and organic-rich soil amendment that has great value for agriculture. The drying process involves converting solids at approximately 25-30% solids content to a dry, stable biosolids pellet. The majority of the input material is recycled to the mixing step upstream of the dryer to achieve a more uniform particle size distribution. The objective of this work was to investigate use of polyelectrolyte amendments to promote uniformity in dried biosolids pellet size. Biosolids samples were collected at the New England Fertilizer Company (NEFCO) facility located in Quincy, MA, U.S. The biosolids samples were characterized by scanning electron microscopy (SEM), inductively coupled plasma/mass spectrometry (ICP-MS), dynamic light scattering (DLS) and zeta potential measurements. Five polyelectrolytes, polyethyleneimine (PEI), polydiallyldimethyl-ammonium chloride (PDADMAC), polyallyamine (PAM), polyacrylic acid (PAA) and polyethylene oxide (PEO) were selected as candidate amendments for surface properties modification trials. The results indicated that three cationic polyelectrolytes, PDADMAC, PEI and PAM, reduced the (absolute value) zeta potentials of the biosolids surfaces to near zero. The optimal doses for reducing the zeta potentials were found to be 0.008 mg PEI/mg solids; 0.005 mg PAM/mg solids and 0.03 mg PDADMAC/mg solids, respectively. The anionic polyelectrolyte PAA and nonionic polymer PEO were found to be ineffective for modifying the zeta potential of the biosolids. The changes in particle size distributions of the biosolids using the three cationic polyelectrolytes were determined by dynamic light scattering (DLS) measurements. Of the three cationic polyelectrolytes, only PDADMAC was found to increase the biosolids particle size from average size of 340 nm to 3600 nm with 240 min contact time. This indicates the potential for PDADMAC as an amendment for improving the biosolids drying process as it was able to decrease the number of fines and increase the “green” biosolids pellet size.

Burgeoning fields of nanomedicine and theranostics are propelled forward by the creative and systematic design of synthetic polymers. Cationic polyelectrolytes, comprising covalently-linked cations within each repeat unit, have drawn particular interest for their ability to bind nucleic acids and permeate cell membranes. Expanding the design space of these systems, we introduced a new family of polyelectrolytes based on the carbon-centered cyclopropenium cation. Cyclopropenium is a modular, aromatic building block with unique structural and electronic properties and, when coupled with modern living polymerization techniques, can be incorporated into macromolecules with precise size, shape, and composition. This thesis describes the translation of cationic polyelectrolytes based on cyclopropenium to biomedical applications and is structured into three parts. The first part evaluates cyclopropenium polymers as candidate non- viral vectors for gene therapy and demonstrates that some derivatives are both biocompatible and efficacious transfection agents. In the second part, nanoparticles comprising cyclopropenium are exploited as live-cell image contrast agents and evolved into potentially theranostic tools. The final part describes a facile route to a novel class of cyclopropenium-based polymers. Together, this thesis illustrates that cyclopropenium is a versatile component of polyelectrolytes, poised to address leading biological challenges.

DNA condensates have attracted the attention of biophysicists, biochemists and polymer physicists for more than thirty years. In the biological community, the quest to understand DNA toroid formation has been motivated by its relevance to gene packing in certain viruses and by the potential use of DNA toroids in artificial gene delivery (e.g. gene therapy). In the physical sciences, DNA toroids are appreciated as a superb model system for studying particle formation by the collapse of a semiflexible, polyelectrolyte polymer. The thesis includes an analysis of the kinetic and thermodynamic factors governing DNA condensate morphology in solution, and discusses implications for future applications of DNA condensation in vitro as a model system for testing theories of polyelectrolyte collapse. In addition, DNA condensation by folded bovine protamine, a naturally occurring multivalent oligopeptide responsible for packing genomic DNA in bovine sperm cells, has been studied as well. The analysis of morphology, size, DNA strand packing density, and the stability of structural integrity of DNA condensates obtained with folded bovine protamines suggests that we have reconstituted native sperm cell chromatin. The results of this study were used to model the local structure of bovine sperm cell chromatin.

Thesis (Ph. D.)--Florida State University, 2002. / Advisor: Dr. Joseph B. Schlenoff, Florida State University, College of Arts and Sciences, Dept. of Chemistry. Title and description from dissertation home page (viewed Sept. 29, 2003). Includes bibliographical references.

x, 131 leaves : photos., graphs, tables ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physical and Inorganic Chemistry, 1979

Dissertation (Ph. D.)--University of Akron, Dept. of Polymer Engineering, 2007. / "December, 2007." Title from electronic dissertation title page (viewed 01/30/2008) Advisor, Kyonsuku Min; Committee members, Mark Soucek, Kevin A. Cavicchi, Gary R. Hamed, Michael H. Cheung; Department Chair, Sadhan C. Jana; Dean of the College, Stephen Z. D. Cheng; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.

Thesis (Ph.D.) -- University of Adelaide, Dept. of Physical and Inorganic Chemistry, 1979.

Thesis (Ph. D.)--Michigan State University. Chemistry, 2008. / Title from PDF t.p. (Proquest, viewed on Aug. 17, 2009) Includes bibliographical references. Also issued in print.

Dissertation (Ph.D.)--Worcester Polytechnic Institute. / Keywords: Fuel Cells, Polymer, Composite, High Temperature, Nafion. Includes bibliographical references. (leaves p.).

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