Rapid Nano-patterning of Polymeric Thin Films with a GA+ Focused Ion Beam PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Rapid Nano-patterning of Polymeric Thin Films with a GA+ Focused Ion Beam PDF full book. Access full book title Rapid Nano-patterning of Polymeric Thin Films with a GA+ Focused Ion Beam by Yajing Liu. Download full books in PDF and EPUB format.
Author: Yajing Liu
Publisher:
ISBN:
Category :
Languages : en
Pages : 442
Get Book Here
Book Description
Author: Yajing Liu
Publisher:
ISBN:
Category :
Languages : en
Pages : 442
Get Book Here
Book Description
Author: Jian Li
Publisher:
ISBN:
Category :
Languages : en
Pages : 410
Get Book Here
Book Description
Author: Abhinav Rastogi
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
The ability to pattern functional polymers at different length scales is important for the advancement of modern science and technology. This dissertation mainly describes the work done on the high resolution patterning of polymer thin films that have a variety of potential uses. The nanoscale patterning of spun-coated polar polymers was demonstrated using environmentally benign supercritical carbon dioxide (scCO2) as a processing solvent. The use of scCO2 as a processing solvent has several technical advantages that help resolve some of the key problems faced in lithography. In addition, it helps reduce the energy and resource usage that can negatively affect the environment. scCO2 is generally a poor solvent for high molecular weight polymers that are used as standard photoresists. Chapter 2 describes a series of fluorinated quaternary ammonium salts that were synthesized and used as CO2 compatible additives to aid the dissolution of polar polymer photoresists in scCO2. Using these dissolution aids, patterns as small as 100 nm lines were obtained with scCO2 development. Chapters 3 and 4 focus on the patterning of high-tech thin polymer films referred to as polymer brushes. In these films the polymer chains are covalently attached to a surface. A direct method of patterning polymer brushes in a single step using electron beam lithography has been described. Polymer brushes of different structures such as poly(methyl methacrylate) (PMMA) brushes , poly(2-hydroxyethyl methacrylate) (PHEMA) brushes, poly(isobutyl methacrylate) (PIBMA) brushes, poly(neopentyl methacrylate) (PNPMA) brushes and poly(2,2,2-trifluoroethyl methacrylate) (PTFEMA) brushes were grown via atom transfer radical polymerization. These brushes were directly patterned using e-beam and their sensitivity to e-beam patterning has been compared and explained. This direct patterning approach produced polymer brush patterns down to 50 nm lines. Due to the number of advantages of using scCO2 as a processing solvent, the dry development of a directly patterned low surface energy coating composed of PTFEMA brushes in scCO2 has been demonstrated in Chapter 4. Using scCO2 as a developer, patterned PTFEMA brushes with 150 nm lines were obtained. Polymer brushes have been used to prepare biocompatible surfaces with reduced non-specific adsorption. Chapter 5 describes the synthesis of a new oligo(ethylene glycol) containing ATRP intiator to prevent non-specific adsorption of biomolecules on polymer brush coated gold electrodes. The adsorption of non-specific antibodies on modified gold electrodes was studied using cyclic voltammetry. Poly(acrylic acid) brushes grown using this new ATRP initiator showed reduced nonspecific binding of the gold electrodes. There has been a continuing need for developing new medical countermeasures for emerging infectious diseases. Chapter 6 describes the role of functionalized poly(acrylic acid) brushes in the development of a biosensor based on sensitive electrochemical detection of the intrinsic catalytic activity of antibodies. Poly(acrylic acid) brushes have been functionalized with 2,4-dinitrophenyl groups (model antigen) and Ni-NTA to immobilize specific antibodies on the sensor surface. The modification of gold surfaces with polymer brushes provides a bio- and electronically compatible substrate with high density of specific haptens with reduced non-specific adsorption.
Author: Xiaoteng Wang
Publisher:
ISBN:
Category : Nanocomposites (Materials)
Languages : en
Pages : 75
Get Book Here
Book Description
Polymer-nanoparticle (NP) composites have been studied extensively as a core material that exhibits advantageous optical, electrical and mechanical properties in nanotechnology. It has been well-established that a specific distribution state of nanoparticles in a polymer matrix is the key issue to optimize a desired polymer nanocomposite (PNC) property. However effective way of controlling the spatial distribution of nanoparticles is still a recurring challenge. Here we demonstrated facile processing approach to fabricate nanocomposite thin films with controlled nanoparticle dispersion state by exploiting the entropic interactions, thereby controlling the macroscopic performance of the material. The interactions of nanoparticles with polymers are mediated by the ligands attached to the nanoparticles. Location and dispersion of polystyrene grafted titanium dioxide (PS-g-TiO2) and hydroxyl-functionalized polyhedral oligomeric silsesquioxanes (DPOSS) molecular nanoparticles in homopolymer matrices under various annealing conditions were investigated. PS-g-TiO2 NP filled low molecular weight polystyrene thin films were thermally annealed under nanoscale pattern confinement, which was fabricated by imprinting digital recording media discs (DVD) pattern onto polydimethylsiloxane (PDMS). The NP dispersion changed from randomly distributed to aggregating at the elevated regions of the imprinted films due to the entropic interaction caused by the size difference between the particles and the matrix chains. DPOSS-PS is a type of giant shape amphiphiles which are built up by covalent bonding of molecular nanoparticles. When added to low molecular weight homopolymer matrices, DPOSS-PS nanoparticles exhibited better dispersion in PMMA than in PS matrix. Additionally, to understand the morphology transition and phase separation kinetics, various loading fraction of DPOSS-PS were incorporated into PMMA matrix. Phase separation at multiple length scales was observed when the composition of DPOSS-PS is in the range of 5% and 70%.
Author: Marvin Young Paik
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
Polymers have been used in thin film coatings as a way to produce tailor made surfaces. These thin films have been explored for use in a variety of applications to produce antifouling coatings, corrosion resistant coatings, biocompatible surfaces, and biomedical devices. Polymer brushes, polymer chains tethered to a substrate or surface, synthesized by surface-initiated polymerization have gained significant attention in recent years. As brushes offer a new pathway towards the preparation of functional surfaces and offer long term stability, even in adverse environments, they are attractive for use as high-tech coatings. Patterned polymer thin films have also seen growing interest for various applications. This dissertation will focus on the top-down direct patterning of polymer brushes and the bottom-up self-assembly of block copolymer thin films. A new approach to creating patterned polymer brushes is highlighted, which is a simpler approach than what is conventionally done. Various polymer brushes were patterned directly using electron beam lithography to create high resolution patterned polymer brushes in a single step. This method was then used to demonstrate the unique ability to create sub-surface patterns within the brush. Additionally, direct patterning was used to create high resolution patterned binary polymer brushes of PMMA and PEGMA. With this binary patterned surface, a surface that responds to its local environment was created. This thesis also details characterization techniques used in probing polymer thin films to better understand how to improve block copolymer self-assembly. By using a powerful technique called grazing incidence small angle X-ray scattering (GISAXS) on solvent vapor annealed block copolymer thin films while monitoring the solvent vapor swollen film thickness and controlling the film swelling with a nitrogen counterflow, the work presented demonstrates how to accurately determine the processing conditions necessary for the annealing process to take place. This process also provides information as to what changes are occurring during the annealing process. Another characterization technique known as near edge X-ray absorption fine structure (NEXAFS) is also highlighted. A more exact calculation of the electron escape depth (EED) for NEXAFS is done using polymer brushes as the calibration sample. With this information, we can do composition depth profiling on our polymer thin films to identify what is at the surface.
Author: Joshua Max Katzenstein
Publisher:
ISBN:
Category :
Languages : en
Pages : 460
Get Book Here
Book Description
Polymer thin films are ubiquitous in a variety of everyday applications from cookware to packaging. Light can be used to both probe and manipulate the mobility of polymers in thin films. The first project involves the self-diffusion of poly(isobutyl methacrylate) (PiBMA) in thin films using fluorescence recovery after patterned photobleaching (FRAPP). PiBMA is an ideal polymer for this study because it exhibits a film thickness-independent glass transition temperature (Tg) on silicon oxide substrates in film thicknesses down to 14 nm. Since the diffusion coefficient of a polymer depends on the proximity of the experimental temperature to its Tg, nanoconfined diffusion can be measured without superimposed influence from Tg nanoconfinement effects. In this study, self-diffusion of PiBMA parallel to the confining interfaces was found to be film thickness independent to ~30 nm. The reason for the film thickness independence of the Tg of PiBMA is the balance between enhanced mobility at the free interface and hydrogen bonding with the substrate. However, when hydroxyls on the substrate are masked, the Tg of PiBMA decreases with decreasing film thickness. In this case, the diffusion coefficient increases with decreasing film thickness in a way consistent with additional distance from Tg. The second project involves a new approach for creating topographic patterns in thin films via the Marangoni effect, which describes how small variations in surface energy can promote dramatic movement of fluids. Topographic patterns created using this method are potentially useful in a variety of applications, such as the creation of soft lithography stamps. Using a photomask, surface energy gradients can be patterned into solid polymer films. Upon heating the polymer film to a liquid state the Marangoni effect causes the polymer to flow creating three-dimensional topography. This technique was first demonstrated in polystyrene, which undergoes a partial dehydrogenation of the polymer backbone upon photoexposure. However, as exposed and unexposed regions inter-diffuse the topographic features decay. A solution to this problem is to use two orthogonally acting photosensitizers in the polymer film, one for topography creation, and the other for cross-linking which stabilizes the topography at high temperature.
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 568
Get Book Here
Book Description
Author: Zhiming M. Wang
Publisher: Springer Science & Business Media
ISBN: 331902874X
Category : Technology & Engineering
Languages : en
Pages : 536
Get Book Here
Book Description
FIB Nanostructures reviews a range of methods, including milling, etching, deposition, and implantation, applied to manipulate structures at the nanoscale. Focused Ion Beam (FIB) is an important tool for manipulating the structure of materials at the nanoscale, and substantially extends the range of possible applications of nanofabrication. FIB techniques are widely used in the semiconductor industry and in materials research for deposition and ablation, including the fabrication of nanostructures such as nanowires, nanotubes, nanoneedles, graphene sheets, quantum dots, etc. The main objective of this book is to create a platform for knowledge sharing and dissemination of the latest advances in novel areas of FIB for nanostructures and related materials and devices, and to provide a comprehensive introduction to the field and directions for further research. Chapters written by leading scientists throughout the world create a fundamental bridge between focused ion beam and nanotechnology that is intended to stimulate readers' interest in developing new types of nanostructures for application to semiconductor technology. These applications are increasingly important for the future development of materials science, energy technology, and electronic devices. The book can be recommended for physics, electrical engineering, and materials science departments as a reference on materials science and device design.
Author:
Publisher: Academic Press
ISBN: 012812296X
Category : Technology & Engineering
Languages : en
Pages : 1881
Get Book Here
Book Description
Comprehensive Nanoscience and Technology, Second Edition, Five Volume Set allows researchers to navigate a very diverse, interdisciplinary and rapidly-changing field with up-to-date, comprehensive and authoritative coverage of every aspect of modern nanoscience and nanotechnology. Presents new chapters on the latest developments in the field Covers topics not discussed to this degree of detail in other works, such as biological devices and applications of nanotechnology Compiled and written by top international authorities in the field
Author:
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 2018
Get Book Here
Book Description
