Physical Sciences and Mathematics Commons^™

Self-Assembly And Ring-Opening Metathesis Polymerization Of A Bifunctional Carbonate–Stilbene Macrocycle, Yuewen Xu, Weiwei L. Xu, Mark D. Smith, Linda S. Shimizu

Faculty Publications

No abstract provided.

Rhodizonic Acid On Noble Metals: Surface Reactivity And Coordination Chemistry, Donna A. Kunkel, James Hooper, Scott Simpson, Sumit Beniwal, Katie L. Morrow, Douglas C. Smith, Kimberly Cousins, Stephen Ducharme, Eva Zurek, Axel Enders

Axel Enders

A study of the two-dimensional crystallization of rhodizonic acid on the crystalline surfaces of gold and copper is presented. Rhodizonic acid, a cyclic oxocarbon related to the ferroelectric croconic acid and the antiferroelectric squaric acid, has not been synthesized in bulk crystalline form yet. Capitalizing on surface-assisted molecular self-assembly, a two-dimensional analogue to the well-known solution-based coordination chemistry, two-dimensional structures of rhodizonic acid were stabilized under ultrahigh vacuum on Au(111) and Cu(111) surfaces. Scanning tunneling microscopy, coupled with first-principles calculations, reveals that on the less reactive Au surface, extended two-dimensional islands of rhodizonic acid are formed, in which the molecules …

Ligand-Receptor Interactions For Supramolecular Disassembly With Applications In Screening And Drug Delivery, Diego Amado Torres

Doctoral Dissertations

Proteins have the capacity to bind specific sets of compounds known as ligands, these are small molecules with a recurrent theme in their molecular design that is a characteristic exploited here to (i) identify particular affinities of small molecules for proteins with the aim of using them as ligands, inhibitors, or targeting moieties in more complex systems by means of a methodology that screens small molecules based on protein affinity; (ii) decorate a self-assembling supramolecular system at different positions, making it responsive to a complementary protein with the aim of exploring differences in disassembly and sensitivity of the release of …

Physical And Magnetic Properties Of Magnetic Nanoparticle Arrays, Abdul Rahman Mohtasebzadeh

Theses and Dissertations

Using Scanning Electron Microscope (SEM) , Atomic Force Microscope (AFM) and Vibrating Sample Magnetometer (VSM) I studied magnetic-field directed self-assembly of magnetic nanoparticles into patterned arrays on the surface of perpendicular magnetic recording media. A controllable machine was used to coat super paramagnetic nano particles onto the surface of perpendicular recording media for different time intervals. Self assembled nano particles on the surface of the media, were transferred to a polymer layer to observe physical properties. Results from imaging shows that the average width and height of arrays is increasing as a function of time. Width of arrays varies with …

Exponential Replication Of Patterns In The Signal Tile Assembly Model, Alexandra Keenan, Robert Schweller, Xingsi Zhong

Computer Science Faculty Publications and Presentations

Chemical self-replicators are of considerable interest in the field of nanomanufacturing and as a model for evolution. We introduce the problem of self-replication of rectangular two-dimensional patterns in the practically motivated Signal Tile Assembly Model (STAM) [9]. The STAM is based on the Tile Assembly Model (TAM) which is a mathematical model of self-assembly in which DNA tile monomers may attach to other DNA tile monomers in a programmable way. More abstractly, four-sided tiles are assigned glue types to each edge, and self-assembly occurs when singleton tiles bind to a growing assembly, if the glue types match and the glue …

Ligand-Receptor Interactions For Supramolecular Disassembly With Applications In Screening And Drug Delivery, Diego F. Amado Torres

Diego Amado Torres

Proteins have the capacity to bind specific sets of compounds known as ligands, these are small molecules with a recurrent theme in their molecular design that is a characteristic exploited here to (i) identify particular affinities of small molecules for proteins with the aim of using them as ligands, inhibitors, or targeting moieties in more complex systems by means of a methodology that screens small molecules based on protein affinity; (ii) decorate a self-assembling supramolecular system at different positions, making it responsive to a complementary protein with the aim of exploring differences in disassembly and sensitivity of the release of …

The Surface Chemistry Of Adatom Mediated Oligomers Of Aromatic Diisocyanides And Dithiols On Au(111) And Granular Films, John Kestell

Theses and Dissertations

Abstract

The Surface Chemistry of Adatom Mediated Oligomers

of Aromatic Diisocyanides and Dithiols on Au(111) and Granular Films

by

John D. Kestell

The University of Wisconsin-Milwaukee

Under the supervision of Professor W. T. Tysoe

Two seminal events are thought by many to be the birth of nanotechnology and molecular electronics. In 1959, Nobel Laureate Richard Feynman gave his famous "There's Plenty of Room at the Bottom" lecture to an American Physical Society meeting at Caltech. The transistor had been invented by Bell Laboratories in 1947, and already the race was on for device miniaturization. Feynman's lecture focused on some of …

Effect Of Nanoscale Confinement On Glass Transition Of Polystyrene Domains From Self-Assembly Of Block Copolymers, C. G. Robertson, T. E. Hogan, M. Rackaitis, Judit D. Puskas, X. Wang

Judit E. Puskas

The understanding of size-dependent properties is key to the implementation of nanotechnology. One controversial and unresolved topic is the influence of characteristic size on the glass transition temperature (T(g)) for ultrathin films and other nanoscale geometries. We show that T(g) does depend on size for polystyrene spherical domains with diameters from 20 to 70 nm which are formed from phase separation of diblock copolymers containing a poly(styrene-co-butadiene) soft block and a polystyrene hard block. A comparison of our data with published results on other block copolymer systems indicates that the size dependence of T(g) is a consequence of diffuse interfaces …

Fracture And Failure Of Nanoparticle Monolayers And Multilayers, Yifan Wang, Pongsakorn Kanjanaboos, Edward Barry Edward Barry, Sean P. Mcbride, Xiao-Min Lin, Heinrich M. Jaeger

Physics Faculty Research

We present an experimental investigation of fracture in self-assembled gold nanoparticle mono- and multilayers attached to elastomer substrates and subjected to tensile stress. Imaging the fracture patterns down to the scale of single particles provides detailed information about the crack width distribution and allows us to compare the scaling of the average crack spacing as a function of strain with predictions by shear-lag models. With increasing particle size, the fracture strength is found to increase while it decreases as the film thickness is built up layer by layer, indicating stress inhomogeneity in the thickness dimension.

Self-Assembled Nanocrystalline Zno Thin Film Transistor Performance Optimization For High Speed Applications, Burhan Bayraktaroglu, Kevin Leedy

Turkish Journal of Physics

ZnO nanocrystals grown at relatively low temperatures using various vacuum deposition techniques can yield semiconducting thin films of self-assembled nanocolumns 20-50 nm in diameter. Such films are suitable for the fabrication of high speed and transparent thin film transistors (TFTs). Unlike amorphous TFTs, the performance of ZnO transistors depends both on the crystal quality of nanocrystals and the electrical properties of boundary layers between them. We investigated the use of radio frequency sputtering, atomic layer deposition, and pulsed laser deposition techniques to fabricate self-assembled nanocrystalline thin films and determined the influence of deposition conditions on the performance of transistors. Device …

Nanosphere Lithography - Exploiting Self-Assembly On The Nanoscale For Sophisticated Nanostructure Fabrication, Eser Metin Akinoglu, Anthony John Morfa, Michael Giersig

Turkish Journal of Physics

We demonstrate the fabrication of sophisticated nanostructures using nanosphere lithography (NSL). These include periodic triangular and pyramidal islands as well as periodically perforated thin films and cavities on the nano- and microscale. Furthermore, periodic arrays of vertically standing multiwalled carbon nanotubes are grown by plasma enhanced chemical vapor deposition from catalyst islands that were prepatterned by NSL. Moreover, we discuss the applicability of NSL to rough surfaces and show that the ratio between nanosphere size and roughness is determinant of the resulting nanostructure produced. Excellent, limited, and bad applicability of NSL are shown for smooth, rough, and very rough surfaces, …

Linear Assembly And 3d Networks Of Peptide Modified Gold Nanoparticles, Şaban Kalay, Clement Blanchet, Mustafa Çulha

Turkish Journal of Chemistry

The charge and size of molecules chemically attached to nanoparticles (NPs) play an important role in their interaction behavior in suspensions. Gold nanoparticles (AuNPs) were modified systematically with peptides and the modification was verified with surface-enhanced Raman scattering (SERS). The behavior of the modified AuNPs in suspension and at the liquid--solid interface was monitored using small angle X-ray scattering (SAXS), UV/Vis spectroscopy and dynamic light scattering (DLS) in suspension, and atomic force microscopy (AFM) at the solid--liquid interface. It was found that while negatively charged peptide modified AuNPs behave very similar to citrate reduced AuNPs due to their negatively charged …

Synthesis And Characterization Of Coloumnar Mesophases Of Novel Substituted Dibenzanthracenes And Their Donor-Acceptor Mixtures, Katie M. Psutka

Theses and Dissertations (Comprehensive)

In this thesis, the synthesis and liquid crystalline properties of a series of novel dibenz[a,c]anthracenes are reported. Specifically, two dibenzanthracenecarboxylate derivatives were prepared and were found not to exhibit a mesophase. In contrast, a series of novel N-substituted dibenzanthracenedicarboximides was also synthesized and found to exhibit broad columnar temperature ranges. Several dibenzanthracenedicarboximides substituted with different alkyl chains on the nitrogen atom were prepared and their mesomorphic temperature ranges were characterized. In general, it was found that having a longer, more flexible alkyl chain on the nitrogen atom resulted in a broadening of the columnar temperature range via a lowering …