Physical Sciences and Mathematics Commons^™

Cationic Metallocene-Containing Polymers: From Synthesis To Applications, Jiuyang Zhang

Theses and Dissertations

Metallopolymers, with the combination of metals and polymeric framworks, have attracted a lot of attention during the past decades. The development of metallopolymers has been largely driven by the desire to combine the synthetic efficiency and versatility of an organic polymer framework with the unique redox, responsive and catalytic properties of inorganic metals. Among different kinds of metallopolymers, metallocene-containing polymers， have been widely utilized for applications ranging from electrochemical sensors to templates for advanced inorganic catalysts to battery materials, due to their unique physicochemical properties. In the first part of my thesis, we showed controlled/living polymerization strategies to prepare well-defined …

Coordination Nature Of 4-Mercaptoaniline To Sn(Ii) Ion: Formation Of A One Dimensional Coordination Polymer And Its Decomposition To A Mono Nuclear Sn(Iv) Complex, Eon S. Burkett, Tasneem A. Siddiquee

Chemistry Faculty Research

The coordination of the bifunctional ligand 4-mercaptoaniline with aqueo us tin(II) metal ion was studied. A coordination polymer was synthesized when an aqueous solution of SnCl2 was treated with 4-MA. The crystalline material is stable under atmospheric conditions retaining its oxidation state. However, when submerged in a solution saturated with oxygen, the compound oxidizes to a mononuclear tin(IV) complex. Both the compounds were characterized by single crystal X-ray diffraction studies. Although the structure of the tin(IV) complex was previously reported, crystal structure of this compound was redetermined.

Hi-Fidelity Simulation Of The Self-Assembly And Dynamics Of Colloids And Polymeric Solutions With Long Range Interactions, Mahdy Malekzadeh Moghani

Doctoral Dissertations

Modeling the equilibrium properties and dynamic response of the colloidal and polymeric solutions provides valuable insight into numerous biological and industrial processes and facilitates development of novel technologies. To this end, the centerpiece of this research is to incorporate the long range electrostatic or hydrodynamic interactions via computationally efficient algorithms and to investigate the effect of these interactions on the self-assembly of colloidal particles and dynamic properties of polymeric solutions. Specifically, self-assembly of a new class of materials, namely bipolar Janus nano-particles, is investigated via molecular dynamic simulation in order to establish the relationship between individual particle characteristics, such as …

Degradation Of Protective Glove Materials Exposed To Commercial Products: A Comparative Study Of Tensile Strength And Gravimetric Analyses, Todd B. Pelham

Electronic Theses, Projects, and Dissertations

ABSTRACT

Current glove guides attempt to assist in recommending which type of glove is appropriate for handling chemicals; however, they include information on less than 1% of the 89 million chemical products available today.

This study offers a solution by testing five durable polymer materials against 50 chemicals, using two rapid chemical degradation assessment techniques. The first technique involves gravimetric analysis of the weight change following constant immersion against the chemical mixture. The second method uses tensile strength to assess molecular changes in the polymer structure.

This study is focused on addressing three issues of concern. First, this study examines …

Surgical Adhesive From Mussel Mimetic Polymer, Jenna Desousa, Cori Jenkins, Jonathan Wilker

The Summer Undergraduate Research Fellowship (SURF) Symposium

Injuries involving damaged tissues are currently repaired through an invasive technique involving the use of screws, plates and sutures as support, which can damage these tissues. The biomedical field currently lacks an adhesive that can replace harmful implants. A surgical adhesive can provide a quick and easy alternative, which will minimize the risk of damaging healthy tissue in surgery. Inspiration for such materials can be found by looking at marine mussels as they are able to stick to nearly any surface, even in wet environments. Marine mussels affix themselves to different surfaces using adhesive plaques consisting of various proteins. Polymer …

Composition Dependence Of The Flory-Huggins Interaction Parameter In Polymer Blends: Structural And Thermodynamic Calculations, Travis H. Russell

Doctoral Dissertations

Flory-Huggins Theory has been the basis for understanding polymer solvent and blended polymer thermodynamics for much of the last 60 years. Within this theory, a parameter (χ) [chi] was included to quantify the enthalpic energy of dispersion between distinct components. Thin film self-assembly of polymer melts and block copolymers depends critically on this parameter, and in application, χ has generally been assumed to be independent of the concentrations of the individual components of the system. However, Small-Angle Neutron Scattering data on isotopic polymer blends, such as polyethylene and deuterated polyethylene, have shown a roughly parabolic concentration dependency for …

A Soft Condensed Matter Approach Towards Mathematical Modelling Of Mass Transport And Swelling In Food Grains, Michael Chapwanya, N. Misra

Articles

Soft condensed matter (SCM) physics has recently gained importance for a large class of engineering materials. The treatment of food materials from a soft matter perspective, however, is only at the surface and is gaining importance for understanding the complex phenomena and structure of foods. In this work, we present a theoretical treatment of navy beans from a SCM perspective to describe the hydration kinetics. We solve the transport equations within a porous matrix and employ the Flory–Huggin’s equation for polymer–solvent mixture to balance the osmotic pressure. The swelling of the legume seed is modelled as a moving boundary with …

Effects Of Varying The Cure Profiles Of An Epoxy-Amine System, Patrick W. Hollingsworth

Honors Theses

The cure of an epoxy prepolymer with an amine hardener induces stress in thermosetting systems. The extent of residual stresses in the cured epoxy-amine thermosets are dependent on several factors; one of which is the cure profile utilized. The effect of cure profile on cure induced stresses of an epoxy-amine thermoset was examined in the current study. A difunctional epoxide based on diglycidyl ether of bisphenol-A (DGEBA) and a tetrafunctional amine curative were used to conduct this study. Two cure profiles were selected to prepare samples of varying degrees of stress in the cured thermosets. The first was constant heating …

Investigation Of Energy Alignment Models At Polymer Interfaces, Wenfeng Wang

USF Tampa Graduate Theses and Dissertations

The presented study investigated the Induced Density of Interface States (IDIS) model at different polymer interfaces by using photoemission spectroscopy in combination with electrospray deposition.

In recent years, organic electronics have attracted considerable attention due to their advantages of low-cost and easy-fabrication. The performance of such devices crucially depends on the energy barrier that controls the interface charge transfer. A significant effort has been made to explore the mechanisms that determine the direction and magnitude of charge transfer barriers in these devices. As a result of this effort, the IDIS model was developed to predict the energy alignment at metal/organic …

Tensile Testing Of Individual Glassy, Rubbery And Hydrogel Electrospun Polymer Nanofibres To High Strain Using The Atomic Force Microscope, Adrian Gestos, Philip G. Whitten, Geoffrey M. Spinks, Gordon G. Wallace

Gordon Wallace

The production and use of polymer nanofibre assemblies prepared by electrospinning is now widespread. It is known that the tensile properties of electrospun polymer fibres can be different to those of bulk polymers. Here, we report a general method for measuring the tensile properties of individual electrospun nanofibres that employs a commercial atomic force microscope. Methods for preparing samples, force calibration and calculation of tensile stress and strain are described along with error estimation. By appropriate choice of AFM cantilever, it is shown that the tensile stress-strain curves can be measured for glassy, rubbery and gel polymer nanofibres. Testing can …

A Merocyanine-Based Conductive Polymer, Klaudia K. Wagner, Michele Zanoni, Anastasia Elliott, Pawel W. Wagner, Robert P. Byrne, Larisa Florea, Dermot Diamond, Keith Gordon, Gordon G. Wallace, David L. Officer

Gordon Wallace

We report the first example of a conducting polymer with a merocyanine incorporated into the polymer backbone by electropolymerisation of a spiropyran moiety covalently linked between two alkoxythiophene units. Utilising the known metal coordination capabilities of merocyanines, introduction of cobalt ions into the electropolymerisation led to an enhancement of the conductivity, morphology and optical properties of the polymer films.

Force Control Of A Tri-Layer Conducting Polymer Actuator Using Optimized Fuzzy Logic Control, Mehmet Itik, Mohammadreza Sabetghadam, Gursel Alici

Australian Institute for Innovative Materials - Papers

Conducting polymers actuators (CPAs) are potential candidates for replacing conventional actuators in various fields, such as robotics and biomedical engineering, due to their advantageous properties, which includes their low cost, light weight, low actuation voltage and biocompatibility. As these actuators are very suitable for use in micro-nano manipulation and in injection devices in which the magnitude of the force applied to the target is of crucial importance, the force generated by CPAs needs to be accurately controlled. In this paper, a fuzzy logic (FL) controller with a Mamdani inference system is designed to control the blocking force of a trilayer …

Optical And Electrochemical Methods For Determining The Effective Area And Charge Density Of Conducting Polymer Modified Electrodes For Neural Stimulation, Alexander R. Harris, Paul Molino, Robert M. I Kapsa, Graeme M. Clarke, Antonio Paolini, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

Neural stimulation is used in the cochlear implant, bionic eye, and deep brain stimulation, which involves implantation of an array of electrodes into a patient's brain. The current passed through the electrodes is used to provide sensory queues or reduce symptoms associated with movement disorders and increasingly for psychological and pain therapies. Poor control of electrode properties can lead to suboptimal performance; however, there are currently no standard methods to assess them, including the electrode area and charge density. Here we demonstrate optical and electrochemical methods for measuring these electrode properties and show the charge density is dependent on electrode …

The Synthesis Of Polyimides Containing Oxyalkylene Units, Kristy Wickman

Browse all Theses and Dissertations

A series of oxyalkylene containing diamines, 1,4-bis(2-(4-aminophenoxy)-ethoxy)benzene, 2,2-bis[4-(2-(4-nitrophenoxy)ethoxy)phenyl]hexafluoropropane, 9,9-bis(4-(2-(4-nitrophenoxy)ethoxy)phenyl)fluorene, and bis(4-(2-(4-nitrophenoxy)ethoxy)-phenyl)diphenylmethane, has been synthesized from the reduction of 1,4-bis(2-(4-nitrophenoxy)ethoxy)benzene, 2,2-bis[4-(2-(4-nitrophenoxy)ethoxy)phenyl]-hexafluoropropane, 9,9-bis(4-(2-(4-nitrophenoxy)ethoxy)phenyl)fluorene, bis(4-(2-(4-nitrophenoxy)ethoxy)phenyl)diphenylmethane, respectively. The diamine compounds were reacted reacted with 6FDA to obtain the corresponding polyimide. The polymerization was done in a one-pot reaction with m-cresol and isoquinoline. The polyimides displayed glass transition temperatures ranging from 186-231°C and thermal stability <400°C.

The Role Of Emissive Charge Transfer States In Two Polymer-Fullerene Organic Photovoltaic Blends: Tuning Charge Photogeneration Through The Use Of Processing Additives, Tracey M. Clarke, Jeff Peet, Christoph Lungenschmied, Nicolas Drolet, Xinhui Lu, Benjamin M. Ocko, Attila Mozer, Maria Antonietta Loi

Australian Institute for Innovative Materials - Papers

The role of charge transfer (CT) states in organic photovoltaic systems has been debated in the recent literature. In this paper the device performances of two structurally analogous polymers PDTSiTTz (also known as KP115) and PCPDTTTz blended with PCBM are investigated, focusing on the effect the processing additive diiodooctane (DIO) has on morphology, charge photogeneration, and, in particular, the CT state characteristics. While DIO has a considerable beneficial effect for PCPDTTTz:PCBM photovoltaic devices, negligible effects are observed for PDTSiTTz:PCBM devices. An emissive CT state able to be quenched by DIO was observed for PCPDTTTz:PCBM, despite relatively small morphological changes. This …

One-Step Synthesis Of Graphene/Polypyrrole Nanofiber Composites As Cathode Material For A Biocompatible Zinc/Polymer Battery, Sha Li, Kewei Shu, Chen Zhao, Caiyun Wang, Zaiping Guo, Gordon G. Wallace, Hua-Kun Liu

Australian Institute for Innovative Materials - Papers

The significance of developing implantable, biocompatible, miniature power sources operated in a low current range has become manifest in recent years to meet the demands of the fast-growing market for biomedical microdevices. In this work, we focus on developing high-performance cathode material for biocompatible zinc/polymer batteries utilizing biofluids as electrolyte. Conductive polymers and graphene are generally considered to be biocompatible and suitable for bioengineering applications. To harness the high electrical conductivity of graphene and the redox capability of polypyrrole (PPy), a polypyrrole fiber/graphene composite has been synthesized via a simple one-step route. This composite is highly conductive (141 S cm …

3-Dimensional (3d) Fabricated Polymer Based Drug Delivery Systems, Simon Moulton, Gordon G. Wallace

Australian Institute for Innovative Materials - Papers

Drug delivery from 3-dimensional (3D) structures is a rapidly growing area of research. It is essential to achieve structures wherein drug stability is ensured, the drug loading capacity is appropriate and the desired controlled release profile can be attained. Attention must also be paid to the development of appropriate fabrication machinery that allows 3D drug delivery systems (DDS) to be produced in a simple, reliable and reproducible manner. The range of fabrication methods currently being used to form 3D DDSs include electrospinning (solution and melt), wet-spinning and printing (3-dimensional). The use of these techniques enables production of DDSs from the …