WorldCat Identities

Braun, P. V. (Paul V.)

Works: 102 works in 173 publications in 1 language and 1,139 library holdings
Genres: Conference papers and proceedings 
Roles: Editor
Publication Timeline
Most widely held works by P. V Braun
Nanocomposite science and technology by P. M Ajayan( Book )

22 editions published between 2002 and 2010 in English and held by 573 WorldCat member libraries worldwide

In recent years, nanocomposites have captured and held the attention and imagination of scientists and engineers alike. Based on the simple premise that by using a wide range of building blocks with dimensions in the nanosize region, it is possible to design and create new materials with unprecedented flexibility and improvements in their physical properties. This book contains the essence of this emerging technology, the underlying science and motivation behind the design of these structures and the future, particularly from the perspective of applications. It is intended to be a reference handbook for future scientists and hence carries the basic science and the fundamental engineering principles that lead to the fabrication and property evaluation of nanocomposite materials in different areas of materials science and technology
Nanomaterials and their optical applications : 5-7 August 2003, San Diego, California, USA( )

13 editions published in 2003 in English and held by 140 WorldCat member libraries worldwide

Tuning the optical response of photonic bandgap structures : 4-5 August, 2004, Denver, Colorado, USA by Philippe Max Fauchet( )

10 editions published in 2004 in English and held by 104 WorldCat member libraries worldwide

Tuning the optical response of photonic bandgap structures II : 31 July-1 August, 2005, San Diego, California, USA( )

10 editions published in 2005 in English and held by 98 WorldCat member libraries worldwide

Tuning the optic response of photonic bandgap structures III : 14 August 2006, San Diego, California, USA( )

17 editions published between 2004 and 2006 in English and held by 93 WorldCat member libraries worldwide

Three-dimensional nano- and microphotonics( )

1 edition published in 2007 in English and held by 9 WorldCat member libraries worldwide

Synthesis and evaluation of quadruple hydrogen-bonding modules for smart materials applications by Cyrus A Anderson( )

1 edition published in 2011 in English and held by 2 WorldCat member libraries worldwide

The research described herein pertains to the design, synthesis and evaluation of DNA base pair mimics for supramolecular and materials chemistry applications. Recently, the ureido-7-deazaguanine (DeUG) and 2,7-diamidonaphthyridine (DAN) H-bonding modules have been shown to form a highly stable complex (Kassoc = 10^8 M^⁰́₃1) in chloroform solution. Use of these units in applications requires derivatives that can be incorporated into polymers and onto surfaces. A method for the synthesis of non-symmetric diamidonaphthyridines from bromonaphthyridines using copper catalysis with aqueous ammonia at ambient temperature and pressure is detailed in chapter two. Chapter three relates several general strategies for the preparation of functional DeUG derivatives. The chemistry described in the first two chapters allows the synthesis of DAN and DeUG units featuring vinyl monomers, azide, alkyne, and other reactive groups for various coupling chemistries. Evaluation of the DAN and DeUG pair as a coupling agent for improving the interfacial adhesion between styrene and glass is explored in chapter four. Potential applications include advanced adhesives and coatings. Incorporation of the DAN unit into polystyrene via C⁰́₃H activation and Suzuki-Miyaura coupling and functionalization of glass substrates with organosilanes are reported. Materials characterization and mechanical test results are consistent with the recognition units playing a role in the improved adhesive response as compared to an unmodified system. Progress toward a photoresponsive bisureidonaphthyridine H-bonding unit is disclosed in chapter 5. The photoresponsive naphthyridine is designed to allow reversible, light-driven modulation of the binding between the naphthyridine and DeUG. Synthetic results are discussed and binding data for bisureidonaphthyridine and DeUG are reported. The conformational change required of bisureidonaphthyridine prior to complexation with DeUG results in a smaller association constant as compared to the DAN·DeUG system, which does not require reorganization prior to binding. The binding properties of the DAN·DeUG and bisuredionaphthyridine-DeUG units allow complexation induced control over the conformational preference of bisureidonaphthyridine
Three-dimensional photonic crystal optoelectronics by Erik C Nelson( )

1 edition published in 2011 in English and held by 2 WorldCat member libraries worldwide

Photonic crystals are a class of synthetic materials which can control the absorption, emission and propagation of light to an unprecedented degree. In order to fully utilize their properties defect must be added to photonic crystals to direct the flow of light, and light emitting structures must be incorporated that have the ability to be electrically pumped. In pursuit of these goals, the coupling of photons into 3D photonic crystals was studied for template-based fabrication methods. A complete lack of coupling was demonstrated for frequencies within and around the photonic band gap due to a surface resonance. The cause of this behavior was studied using experiment and finite-difference time-domain calculations, and a solution developed. The incorporation of defects was studied next and advanced to allow for simultaneous imaging and defect writing using a fluorescent dye and two-photon sensitive photoinitiator. Complete spatial alignment of defects with respect to photonic crystal lattice was achieved using this method. While fabrication techniques such as phase mask lithography may be used to create a large variety of 3D structures, they are typically formed in SU-8 photoresist which cannot survive high temperature processes such as chemical vapor deposition. In order to make these structures accessible for future photonic crystal research a technique was developed to impart thermal stability to polymer templates using ceramic coatings deposited by atomic layer deposition and subsequent high-temperature growth of silicon was performed on the templates. Finally, a method was developed to create 3D photonic crystals from III-V semiconductors using a template based approach and metal-organic vapor phase epitaxy. The result of this work was the fabrication of 3D photonic crystals from high-quality GaAs and the demonstration of the first electrically driven 3D photonic crystal LED
Direct-write assembly of 3D microperiodic scaffolds for tissue engineering applications by Sara T Parker( )

1 edition published in 2010 in English and held by 2 WorldCat member libraries worldwide

Theoretical and experimental studies of bending/stretching of inorganic electronic materials printed on plastic substrates and their practical applications by Sang Il Park( )

1 edition published in 2010 in English and held by 2 WorldCat member libraries worldwide

Flexible electronics based on inorganic devices has attracted increasing interest in versatile applications, from commercial systems, such as flat panel displays, to new possible systems, such as paperlike display, sensors, and medical devices, due to its many potential advantages including established electrical performance in comparison with organic based devices. However, the behavior of inorganic materials on plastic substrate by bending has been not studied well and the degree of bendability has simply defined by the bend radius at which the strain reaches some substantial fraction of a fracture strain (e.g., ~1 %) in a typical inorganic film. This thesis has been focused on the fundamental scientific studies necessary to establish the accurate bending induced mechanics of these systems and demonstration of various new inorganic based applications with high bendable and stretchable properties. Firstly, comprehensive experimental and theoretical studies of bending in flexible inorganic electronics on plastic substrates enable to understand the limits of flexibility and, moreover, improve this property of inorganic electronics on plastic substrate. Secondly, based on these studies, the focus of this thesis has been on the developments of highly bendable arrays of single crystalline silicon solar cells on plastic and highly bendable, stretchable, and deformable III-V compound semiconductor inorganic light emitting diodes (ILEDs) display as practical applications
Amino acid N-carboxyanhydrides and polypeptides: Controlled polymerization, properties and applications by Hua Lu( )

1 edition published in 2011 in English and held by 2 WorldCat member libraries worldwide

Unconventional structured semiconductors and their applications in optoelectronics and photovoltaics by Xiaoying Guo( )

1 edition published in 2010 in English and held by 2 WorldCat member libraries worldwide

Introducing Defects in 3D Photonic Crystals: State of the Art( Book )

2 editions published in 2006 in English and held by 2 WorldCat member libraries worldwide

3D photonic crystals (PhCs) and photonic bandgap (PBG) materials have attracted considerable scientific and technological interest. In order to provide functionality to PhCs, the introduction of controlled defects is necessary; the importance of defects in PhCs is comparable to that of dopants in semiconductors. Over the past few years, significant advances have been achieved through a diverse set of fabrication techniques. While for some routes to 3D PhCs, such as conventional lithography, the incorporation of defects is relatively straightforward; other methods, for example, self-assembly of colloidal crystals (CCs) or holography, require new external methods for defect incorporation. In this review, we will cover the state of the art in the design and fabrication of defects within 3D PhCs. The figure displays a fluorescence laser scanning confocal microscopy image of a y-splitter defect formed through two-photon polymerization within a CC
Optomechanics of two- and three-dimensional soft photonic crystals by Dwarak Krishnan( )

1 edition published in 2011 in English and held by 2 WorldCat member libraries worldwide

Soft photonic crystals are a class of periodic dielectric structures that undergo highly nonlinear deformation due to strain or other external stimulus such as temperature, pH etc. This can in turn dramatically affect optical properties such as light transmittance. Moreover certain classes of lithographically fabricated structures undergo some structural distortion due to the effects of processing, eventually affecting the optical properties of the final photonic crystal. In this work, we study the deformation mechanics of soft photonic crystal structures using realistic physics-based models and leverage that understanding to explain the optomechanics of actual 2-D and 3-D soft photonic crystals undergoing similar symmetry breaking nonlinear deformations. We first study the optomechanics of two classes of 3-D soft photonic crystals: (1) hydrogel and (2) elastomer based material systems. The hydrogel based inverse face-centered-cubic structure undergoes swelling with change in pH of the surrounding fluid. The inverse structure is a network of bulky domains with thin ligament-like connections, and it undergoes a pattern transformation from FCC to L11 as a result of swelling. A continuum scale poroelasticity based coupled fluid-diffusion FEM model is developed to accurately predict this mechanical behavior. Light transmittance simulation results qualitatively explain the experimentally observed trends in the optical behavior with pH change. The elastomer based, lithographically fabricated material experiences shrinkage induced distortion upon processing. This behavior is modeled using FEM with the material represented by a neo-Hookean constitutive law. The light transmittance calculations for normal incidence are carried out using the transfer matrix method and a good comparison is obtained for the positions of first and second order reflectance peaks. A unit cell based approach is taken to compute the photonic bandstructure to estimate light propagation through the structure for other angles of light incidence. To obtain a detailed picture of the change in optical properties due to a pattern transformation, we study simple 2-D elastomer photonic crystals which undergo an interesting structural pattern transformation from simple circular holes to alternately oriented ellipses in a square lattice due to uniaxial compression. The incident light does not have any effect on the properties of the elastomer material. A decomposition of the deformation gradient quickly shows that the pattern transformation is induced by alternating rotations of the interstitial regions and the bending of interconnecting ligaments. Numerical simulations of light transmittance using vector element based FEM analysis of Maxwells equations shows changes in the light energy localization within the material especially in the high energy/low wavelength regions of the spectra. Additionally, with bandstructure calculations on a unit cell of the structure, the optomechanical behavior is completely explained. Finally, computational evidence is provided for a hypothetical 2-D photonic crystal made of a light-sensitive material, which undergoes a structural pattern transformation primarily due to the effect of incident light. The model takes into account the order kinetics of optically induced isomerization (of trans to cis configuration) in the azobenzene-liquid crystal elastomer to compute the transformational strain. This strain, in turn, deforms the structure and hence changes its periodicity and dielectric properties and thus affects the manner in which light gets localized within the material system. This consequently changes the profile of the imposed transformational strain on the deformed structure. The macroscopic strain history shows that prior to the mechanical instability that causes the pattern transformation, there is a period of structural relaxation which initiates the pattern transformation. After the symmetry breaking pattern transformation, the photonic bandstructure is altered significantly. Light does not get localized in the spot regions anymore and stress relaxation dominates. Due to this, the compressive macroscopic strain of the pattern transformed structure starts to decrease indicating a possible cyclical behavior
MRS Workshop Explores the Diversity of 3D Multifunctional Ceramic Composites( Book )

2 editions published in 2005 in English and held by 2 WorldCat member libraries worldwide

The MRS Workshop on Three-Dimensional Multifunctional Ceramic Composites was held at the Beckman Institute on the campus of the University of Illinois at Urbana-Champaign (UIUC) October 3-5, 2005. Organized by Paul V. Braun of UIUC, C. Jeffrey Brinker of the University of New Mexico and Sandia National Laboratories, and Shanhui Fan of Stanford University, the workshop reached an audience of about 100 attendees from academic institutions, government laboratories, and private industry. The scientific and technical underpinnings of self-assembly and properties of self-assembled 3D ceramic, composite and semiconductor structures were emphasized. The technical program consisted of invited presentations from renowned experts, along with selected contributed presentations, posters, and hands-on tutorials given by expert faculty. The topics explored included new developments in 3D photonic crystals, chemical and biological sensors, nanoparticle assemblies, rapid fabrication techniques, active membranes, 3D holographic patterning, and modeling and theory of 3D optical devices
Polymers as directing agents for motions of chemical and biological species by Nihan Yonet Tanyeri( )

1 edition published in 2011 in English and held by 2 WorldCat member libraries worldwide

This thesis involves descriptions of solid surface modifications with various polymeric materials which were used as a guiding agent for motion of chemical and biological species. Quasi-two dimensional poly(oligoethylene glycol) acrylate polymer brush based molecular conduits have been designed with the goal of regulating and controlling the diffusive transport of molecular, e.g. organic dyes, and ionic species, e.g. AuCl4-, and Cu2+ ions, along predefined 2-D pathways. The transport of these chemical species has been examined by both fluorescence and dark field microscopy. The polymer brushes were formed through microcontact printing of an initiator, followed by surface-initiated Atom Transfer Radical Polymerization (SI-ATRP). SI-ATRP enables both 2-D patterning with a resolution of about 1 micrometer, and control over the resultant polymer brush thickness (which was varied from 10-100 nm). A hydrophilic poly(oligoethylene glycol) acrylate brushe was selected because of its potential to dissolve a wide range of hydrophilic species. The transport of fluorescent species can be directly followed. A non-lithographic fabrication method was developed for microfluidic devices used in the diffusion studies. Singular channel microfluidic device was utilized to study the directed organic dye diffusion. The AuCl4-, and Cu2+ ion transport was studied by designing molecular devices with two microfluidic channels. We have demonstrated that the various species of interest diffuse much more rapidly along the predefined pathway than along the bare (polymer brush free) regions of the substrate, demonstrating that diffusive conduits for molecular transport can indeed be formed. The protein resistance of poly(N-isopropylacrylamide) (PNIPAM) brushes grafted from silicon wafers was investigated as a function of the chain molecular weight, grafting density, and temperature. Above the lower critical solution temperature (LCST) of 32°C, the collapse of the water swollen chains, determined by ellipsometry, depends on the grafting density and molecular weight. Ellipsometry, radio assay, and fluorescence imaging demonstrated that, below the LCST, the brushes repel protein as effectively as oligoethylene oxide terminated monolayers. Above 32°C, very low levels of protein adsorb on densely grafted brushes, and the amounts of adsorbed protein increase with decreasing brush grafting densities. Brushes that do not exhibit a collapse transition also bind protein, even though the chains remain extended above the LCST. These findings suggest possible mechanisms underlying protein interactions with end-grafted PNIPAM brushes. 3D porous materials on solid surfaces were built to mimic the corneal basement membrane so that we can monitor direction of the corneal epithelia cells behaviors as the surface topography changes. We have used colloidal crystal templating approach to build the 3D porous structures. Polystyrene (PS) colloids were crystallized in a flow cell. The crystals were filled with acrylamide precursor (including photoinitiator, crosslinker) in the oxygen free aqueous solution. After polymerization of acrylamide under UV exposure, PS colloids were dissolved in chloroform. Thus, 3D porous polyacrylamide hydrogels have been fabricated. The various pore sizes at the 3D porous surface have been obtained by using PS colloids with the colloid diameters ranging from 450 nm to 4000 nm. Human corneal epithelial cell growth, morphology change and adhesion studies have been conducted on the porous polyacrylamide scaffolds. The effect of pore size on human corneal epithelial cell function has been investigated
Development of polymeric drug delivery vehicles for targeted cancer therapy by Rong Tong( )

1 edition published in 2010 in English and held by 2 WorldCat member libraries worldwide

The aim of my Ph. D. thesis is to generalize a method for targeted anti-cancer drug delivery. Hydrophilic polymer-drug conjugates involve complicated synthesis; drug-encapsulated polymeric nanoparticles limit the loading capability of payloads. This thesis introduces the concept of nanoconjugates to overcome difficulties in synthesis and formulation. Drugs with hydroxyl group are able to initiate polyester synthesis in a regio- and chemo- selective way, with the mediation of ligand-tunable Zinc catalyst. Herein, three anti-cancer drugs are presented to demonstrate the high efficiency and selectivity in the method (Chapter 2-4). The obtained particles are stable in salt solution, releasing drugs over weeks in controlled manner. With the conjugation of aptamer, particles are capable to target prostate cancer cells in vitro. These results open the gateway to evaluate the in vivo efficacy of nanoconjugates for target cancer therapy (Chapter 5). Mechanism study of the polymerization leads to the discovery of chemosite selective synthesis of prodrugs with acrylate functional groups. Functional copolymer-drug conjugates will expand the scope of nanoconjugates (Chapter 6). Liposome-aptamer targeting drug delivery vehicle is well studied to achieve reversible cell-specific delivery of non-hydoxyl drugs e.g. cisplatin (Chapter 7). New monomers and polymerization mechanisms are explored for polyester in order to synthesize nanoconjugates with variety on properties (Chapter 8). Initial efforts to apply this type of prodrugs will be focused on the preparation of hydrogels for stem cell research (Chapter 9)
Nanoparticle transport via holographic photopolymerization by John D Busbee( )

1 edition published in 2010 in English and held by 2 WorldCat member libraries worldwide

Engineering and characterizing light-matter interactions in photonic crystals by Andrew Brzezinski( )

1 edition published in 2010 in English and held by 2 WorldCat member libraries worldwide

Photonic crystals can affect the behavior of visible light, and other electromagnetic waves, in ways that are not possible by other means. The propagation of photons can be completely forbidden or the the light can be made to follow a well- defined path. Fluorescent emission can be enhanced for some wavelengths or completely shut off for others, and it is possible to do all this simultaneously in a single structure. However, photonic crystals are very difficult to fabricate as they require precision patterning at sub-micron length scales. This fabrication difficulty has resulted in many of the potential applications for photonic crystals to currently be unrealized. Similarly, there is an abundance of opportunities to explore the workings of photonic crystals and also to develop exciting new methods for their fabrication. The content of this dissertation explores some methods for fabricating photonic crystals, including direct laser writing, interference lithography, colloidal deposition, and chemical vapor deposition. The angle-resolved characterization of photonic crystals is performed on fluorescent photonic crystals that exhibit uniquely photonic effects, which are explained with a simplified model of the electromagnetic wave-functions. Another model is shown to well-explain the emission from fluorescent photonic crystals that are not of sufficient quality to exhibit truly photonic effects. The ability to perform angle- resolved optical characterization is improved with a commercial 4-circle diffractometer. A method to determination the resulting structure of conformal deposition processes proves useful as a tool for the design, modeling, and characterization of photonic crystals. Finally, attempts are made to radically alter the emission of light from rare earth emitters embedded inside photonic crystals
Interference lithography for optical devices and coatings by Abigail T Juhl( )

1 edition published in 2011 in English and held by 2 WorldCat member libraries worldwide

Interference lithography can create large-area, defect-free nanostructures with unique optical properties. In this thesis, interference lithography will be utilized to create photonic crystals for functional devices or coatings. For instance, typical lithographic processing techniques were used to create 1, 2 and 3 dimensional photonic crystals in SU8 photoresist. These structures were in-filled with birefringent liquid crystal to make active devices, and the orientation of the liquid crystal directors within the SU8 matrix was studied. Most of this thesis will be focused on utilizing polymerization induced phase separation as a single-step method for fabrication by interference lithography. For example, layered polymer/nanoparticle composites have been created through the one-step two-beam interference lithographic exposure of a dispersion of 25 and 50 nm silica particles within a photopolymerizable mixture at a wavelength of 532 nm. In the areas of constructive interference, the monomer begins to polymerize via a free-radical process and concurrently the nanoparticles move into the regions of destructive interference. The holographic exposure of the particles within the monomer resin offers a single-step method to anisotropically structure the nanoconstituents within a composite. A one-step holographic exposure was also used to fabricate self- healing coatings that use water from the environment to catalyze polymerization. Polymerization induced phase separation was used to sequester an isocyanate monomer within an acrylate matrix. Due to the periodic modulation of the index of refraction between the monomer and polymer, the coating can reflect a desired wavelength, allowing for tunable coloration. When the coating is scratched, polymerization of the liquid isocyanate is catalyzed by moisture in air; if the indices of the two polymers are matched, the coatings turn transparent after healing. Interference lithography offers a method of creating multifunctional self-healing coatings that readout when damage has occurred
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Audience level: 0.67 (from 0.64 for Three-dime ... to 0.95 for MRS Worksh ...)

Nanocomposite science and technology
Nanomaterials and their optical applications : 5-7 August 2003, San Diego, California, USA
Alternative Names
Braun, P. V.

Braun, Paul

Braun, Paul V.

English (89)