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Full-Text Articles in Physical Sciences and Mathematics
Chemical Approaches For Nanofabrication Based On Colloidal Lithography With Organosilanes, Nanoparticles And Nickel Films: The Role Of Water In Directing Surface Self-Assembly, Neepa Malsi Kumari Kuruppu Arachchige
Chemical Approaches For Nanofabrication Based On Colloidal Lithography With Organosilanes, Nanoparticles And Nickel Films: The Role Of Water In Directing Surface Self-Assembly, Neepa Malsi Kumari Kuruppu Arachchige
LSU Doctoral Dissertations
The capabilities for accomplishing fundamental surface studies with molecular systems are demonstrated in this dissertation using measurement and imaging modes of scanning probe microscopy. Model systems were chosen for investigations of surface self-assembly mechanisms, with an emphasis on understanding the role of interfacial water in surface reactivity. A key strategy for molecular level studies was to prepare nanostructures using protocols with colloidal lithography and scanning probe-based lithography (SPL). Nanofabricated samples were characterized ex situ with contact and tapping-mode atomic force microscopy (AFM) after key reaction steps, providing direct views of changes in surface morphology at the nanoscale. Magnetic sample modulation …
Nanopatterns Of Zinc Phthalocyanines, Gold Nanoparticles, And Porphyrins Prepared Using Particle Lithography: Characterization Of Patterning Steps With Scanning Probe Microscopy, Ashley Marie Taylor
Nanopatterns Of Zinc Phthalocyanines, Gold Nanoparticles, And Porphyrins Prepared Using Particle Lithography: Characterization Of Patterning Steps With Scanning Probe Microscopy, Ashley Marie Taylor
LSU Doctoral Dissertations
The growth and self-assembly of molecules on surfaces can be directly visualized at the molecular level using studies which combine nanoscale lithography and high-resolution imaging. Nanopatterning provides a unique and practical approach for direct views of surface changes after the key chemical steps of nanopatterning, providing landmarks and baselines for measuring growth in vertical and lateral dimensions. Controlling the arrangement of materials on surfaces at the nanoscale can be achieved using particle lithography. Arrays of well-defined nanostructures can be prepared with reproducible geometries and arrangement. Results for the preparation of nanopatterns produced with particle lithography are presented using high resolution …
Studies Of The Properties Of Designed Nanoparticles Using Atomic Force Microscopy, Steve Matthew Deese
Studies Of The Properties Of Designed Nanoparticles Using Atomic Force Microscopy, Steve Matthew Deese
LSU Doctoral Dissertations
The purpose of the research in this dissertation was to elucidate the intrinsic properties of how nanoparticles are different from bulk materials. This was done by mechanical and electronic studies of the properties of designed nanoparticles using advanced modes of atomic force microscopy. Information relating to the work functions, contact potential difference, Young’s Moduli, elasticity, and viscoelasticity can be investigated using state-of-the-art atomic force microscope (AFM) experiments. Subsurface imaging of polystyrene encapsulated cobalt nanoparticles was achieved for the first time using Force Modulation Microscopy (FMM) in conjunction with contact mode AFM. Previously prepared sample of polystyrene coated cobalt nanoparticles were …
Scanning Probe Investigations Of Nanopatterned And Thermo-Responsive Polypeptoids And The Design Of A Sample Stage For Force Modulation Microscopy, Lu Lu
LSU Doctoral Dissertations
Protocols for patterning nanostructures of polymers were developed to enable scanning probe microscopy (SPM) studies of surface properties at the molecular level. A chemically selective surface for patterning polymers was generated by combining particle lithography with organosilane immersion. Poly(N-allyl glycine), a biocompatible and backbone degradable polypeptoid, was grown on Si(111) at confined amine sites using surface-initiated polymerization (also known as the “graft from” approach). A thermo-responsive random copolypeptoid, poly[(N-ethyl glycine)32-r-(N-butyl glycine17)], was pre-synthesized and attached onto a patterned organosilane surface using a thiol-ene click reaction (“graft to” approach). The phase transitions of the copolypeptoid nanostructures in an aqueous environment was …
Application Of Scanning Probe Microscopy To Characterize Physical Properties Of Polymer Brushes, Photoactive Polymers And Rare Earth Oxide Nanostructures, Susan Denise Verberne-Sutton
Application Of Scanning Probe Microscopy To Characterize Physical Properties Of Polymer Brushes, Photoactive Polymers And Rare Earth Oxide Nanostructures, Susan Denise Verberne-Sutton
LSU Doctoral Dissertations
A sample stage for characterizing photoactive materials was developed for studies with scanning probe microscopy (SPM). A sample stage was designed that directs light from a solar simulator via a fiber optic cable to illuminate the sample. Current-sensing and photocurrent measurements can be acquired with a conductive tip. The designed photocurrent stage can be used for SPM systems with a tip-mounted scanner. Current-sensing measurements can be taken with or without illumination to measure the current produced from organic photovoltaic (OPV) or photoconductive samples. Topography, lateral force and current-sensing images are acquired simultaneously, providing information of how nanoscale morphology affects the …
Molecular-Level Investigations Combining Nanoscale Lithography And Atomic Force Microscopy, Chamarra Karmelia Saner
Molecular-Level Investigations Combining Nanoscale Lithography And Atomic Force Microscopy, Chamarra Karmelia Saner
LSU Doctoral Dissertations
In this dissertation, nanostructures of octadecyltrichlorosilane (OTS) and were prepared using particle lithography and evaluated using characterizations with atomic force microscopy (AFM). The nanostructures of OTS were used as a resist for patterning fibronectin, an extracellular matrix protein. Particle lithography provides a practical and reproducible approach to generate billions of nanostructures comprised of organic thin films or nanomaterials. A film of mesospheres can be applied as a surface mask to define the periodicity and size of nanopatterns using processes of self-assembly. A close-packed arrangement of mesospheres is produced spontaneously when monodisperse solutions of latex or silica are dried on a …
Fabrication Of Organosilane Nanostructures As Selective Sites For Surface Chemical Reactions, Kathie Lee Lusker
Fabrication Of Organosilane Nanostructures As Selective Sites For Surface Chemical Reactions, Kathie Lee Lusker
LSU Doctoral Dissertations
Naturally self-assembled mesospheres provide a practical route for controlling the arrangement of materials on surfaces at the nanoscale. Periodic arrays of well-defined nanostructures can be produced with different nanomaterials and interpattern spacings. Results presented in this dissertation demonstrate particle lithography methods developed for fabricating arrays of organosilane nanostructures. Surfaces were designed for the selective deposition of polymers and nanoparticles to produce multicomponent nanopatterns. The approaches for surface patterning provide new directions for studying surface chemistry at the molecular-level, and have practical application for emerging photovoltaic thin film technologies. Atomic force microscopy (AFM) provides unique capabilities for molecular visualization and ultrasensitive …
Dynamic Measurements With Scanning Probe Microscopy: Surface Studies Using Nanostructured Test Platforms Of Metalloporphyrins, Nanoparticles And Amyloid Fibrils, Wilson K. Serem
LSU Doctoral Dissertations
A hybrid imaging mode for characterization of magnetic nanomaterials has been developed, using atomic force microscopy (AFM) combined with electromagnetic sample actuation. Instead of using a coated AFM probe as a magnetic sensor; our strategy is to use a nonmagnetic probe with contact mode AFM to characterize the vibration of magnetic and superparamagnetic nanomaterials responding to the flux of an AC electromagnetic field. We refer to the hybrid imaging mode as magnetic sample modulation (MSM-AFM). An oscillating magnetic field is produced by applying an AC current to a wire coil solenoid placed under the sample stage for tuning selected parameters …
Investigation Of The Structure In Electrodeposited Nanostructured Co/Cu Alloys, Multilayers, And Cofe/Cu Multilayered Nanowires, Erick Jamal Lawson
Investigation Of The Structure In Electrodeposited Nanostructured Co/Cu Alloys, Multilayers, And Cofe/Cu Multilayered Nanowires, Erick Jamal Lawson
LSU Master's Theses
Since the discovery of giant magnetoresistance (GMR) in electrodeposited nanostructured magnetic multilayers and multilayered nanowires, there has been interest throughout the scientific world in the fabrication and characterization of these materials. Magnetic multilayers in the form of thin films can be used as magnetoresistive sensors in the magnetic data storage industry. Arrays of nanowires have the potential for applications in perpendicular ultra-high density data storage and biosensors. Wire-shaped magnetic multilayered nanowires have been shown to exhibit GMR in the so called “current perpendicular-to plane” configuration (CPP-GMR). GMR of multilayers and multilayered nanowires have been investigated in several systems that include …
Shear Induced Orientation In Polymer-Clay Solutions And Their Influence On The Structure In Multilayered Films, Matthew Michael Malwitz
Shear Induced Orientation In Polymer-Clay Solutions And Their Influence On The Structure In Multilayered Films, Matthew Michael Malwitz
LSU Doctoral Dissertations
The influence of shear on viscoelastic solutions of poly(ethylene oxide) (PEO) and clay (Cloisite, CNA) was investigated by rheology and small angle neutron scattering (SANS) under shear. These measurements determined the shear-induced orientation of the clay and the polymer as well as their relaxation behavior after cessation of shear. Comparison of PEO-CNA solutions (~100 nm diameter platelets) to previously studied PEO-Laponite gels (~30 nm diameter platelets) found that the orientation of CNA platelets occurs at much lower shear rates. Additionally, the relaxation times were much longer for CNA platelets than for Laponite platelets. From these solutions and gels, multilayered nanocomposite …