Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Growing Embossed Nanostructures of Polymer Brushes on Wet-Etched Silicon Templated via Block Copolymers.

ABSTRACT: Block copolymer nanolithography has attracted enormous interest in chip technologies, such as integrated silicon chips and biochips, due to its large-scale and mass production of uniform patterns. We further modified this technology to grow embossed nanodots, nanorods, and nanofingerprints of polymer brushes on silicon from their corresponding wet-etched nanostructures covered with pendent SiHx (X?=?1-3) species. Atomic force microscopy (AFM) was used to image the topomorphologies, and multiple transmission-reflection infrared spectroscopy (MTR-IR) was used to monitor the surface molecular films in each step for the sequential stepwise reactions. In addition, two layers of polymethacrylic acid (PMAA) brush nanodots were observed, which were attributed to the circumferential convergence growth and the diffusion-limited growth of the polymer brushes. The pH response of PMAA nanodots in the same region was investigated by AFM from pH 3.0 to 9.0.

SUBMITTER: Lu X

PROVIDER: S-EPMC4740862 | biostudies-other | 2016

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Responsive Adsorption of N-Isopropylacrylamide Based Copolymers on Polymer Brushes.

Project description:We investigate the adsorption of pH- or temperature-responsive polymer systems by ellipsometry and neutron reflectivity. To this end, temperature-responsive poly (N-isopropylacrylamide) (PNIPAM) brushes and pH-responsive poly (acrylic acid) (PAA) brushes have been prepared using the "grafting onto" method to investigate the adsorption process of polymers and its reversibility under controlled environment. To that purpose, macromolecular brushes were designed with various chain lengths and a wide range of grafting density. Below the transition temperature (LCST), the characterization of PNIPAM brushes by neutron reflectivity shows that the swelling behavior of brushes is in good agreement with the scaling models before they collapse above the LCST. The reversible adsorption on PNIPAM brushes was carried out with linear copolymers of N-isopropylacrylamide and acrylic acid, P(NIPAM-co-AA). While these copolymers remain fully soluble in water over the whole range of temperature investigated, a quantitative adsorption driven by solvophobic interactions was shown to proceed only above the LCST of the brush and to be totally reversible upon cooling. Similarly, the pH-responsive adsorption driven by electrostatic interactions on PAA brushes was studied with copolymers of NIPAM and N,N-dimethylaminopropylmethacrylamide, P(NIPAM-co-MADAP). In this case, the adsorption of weak polycations was shown to increase with the ionization of the PAA brush with interactions mainly located in the upper part of the brush at pH 7 and more deeply adsorbed within the brush at pH 9.

| S-EPMC7022643 | biostudies-literature

Surface-Induced ARGET ATRP for Silicon Nanoparticles with Fluorescent Polymer Brushes.

Project description:Well-defined polymer brushes attached to nanoparticles offer an elegant opportunity for surface modification because of their excellent mechanical stability, functional versatility, high graft density as well as controllability of surface properties. This study aimed to prepare hybrid materials with good dispersion in different solvents, and to endow this material with certain fluorescence characteristics. Well-defined diblock copolymers poly (styrene)-b-poly (hydroxyethyl methyl acrylate)-co-poly (hydroxyethyl methyl acrylate- rhodamine B) grafted silica nanoparticles (SNPs-g-PS-b-PHEMA-co-PHEMA-RhB) hybrid materials were synthesized via surface-initiated activators regenerated by electron transfer atom transfer radical polymerization (SI-ARGET ATRP). The SNPs surfaces were modified by 3-aminopropyltriethoxysilane (KH-550) firstly, then the initiators 2-Bromoisobutyryl bromide (BIBB) was attached to SNPs surfaces through the esterification of acyl bromide groups and amidogen groups. The synthetic initiators (SNPs-Br) were further used for the SI-ARGET ATRP of styrene (St), hydroxyethyl methyl acrylate (HEMA) and hydroxyethyl methyl acrylate-rhodamine B (HEMA-RhB). The results indicated that the SI-ARGET ATRP initiator had been immobilized onto SNPs surfaces, the Br atom have located at the end of the main polymer chains, and the polymerization process possessed the characteristic of controlled/"living" polymerization. The SNPs-g-PS-b-PHEMA-co-PHEMA-RhB hybrid materials show good fluorescence performance and good dispersion in water and EtOH but aggregated in THF. This study demonstrates that the SI-ARGET ATRP provided a unique way to tune the polymer brushes structure on silica nanoparticles surface and further broaden the application of SI-ARGET ATRP.

| S-EPMC6680766 | biostudies-literature

Composite block polymer-microfabricated silicon nanoporous membrane.

Project description:Block polymers offer an attractive route to densely packed, monodisperse nanoscale pores. However, their fragility as thin films complicates their use as membranes. By integrating a block polymer film with a thin (100 microm) silicon substrate, we have developed a composite membrane providing both nanoscale size exclusion and fast transport of small molecules. Here we describe the fabrication of this membrane, evaluate its mechanical integrity, and demonstrate its transport properties for model solutes of large and small molecular weight. The ability to block large molecules without hindering smaller ones, coupled with the potential for surface modification of the polymer and the microelectromechanical system style of support, makes this composite membrane an attractive candidate for interfacing implantable sensing and drug-delivery devices with biological hosts.

| S-EPMC2772169 | biostudies-literature

Macroscopic Alignment of Block Copolymers on Silicon Substrates by Laser Annealing.

Project description:Laser annealing is a competitive alternative to conventional oven annealing of block copolymer (BCP) thin films enabling rapid acceleration and precise spatial control of the self-assembly process. Localized heating by a moving laser beam (zone annealing), taking advantage of steep temperature gradients, can additionally yield aligned morphologies. In its original implementation it was limited to specialized germanium-coated glass substrates, which absorb visible light and exhibit low-enough thermal conductivity to facilitate heating at relatively low irradiation power density. Here, we demonstrate a recent advance in laser zone annealing, which utilizes a powerful fiber-coupled near-IR laser source allowing rapid BCP annealing over a large area on conventional silicon wafers. The annealing coupled with photothermal shearing yields macroscopically aligned BCP films, which are used as templates for patterning metallic nanowires. We also report a facile method of transferring laser-annealed BCP films onto arbitrary surfaces. The transfer process allows patterning substrates with a highly corrugated surface and single-step rapid fabrication of multilayered nanomaterials with complex morphologies.

| S-EPMC7497666 | biostudies-literature

Fabrication of Ultrafine, Highly Ordered Nanostructures Using Carbohydrate-Inorganic Hybrid Block Copolymers.

Project description:Block copolymers (BCPs) have garnered considerable interest due to their ability to form microphase-separated structures suitable for nanofabrication. For these applications, it is critical to achieve both sufficient etch selectivity and a small domain size. To meet both requirements concurrently, we propose the use of oligosaccharide and oligodimethylsiloxane as hydrophilic and etch-resistant hydrophobic inorganic blocks, respectively, to build up a novel BCP system, i.e., carbohydrate-inorganic hybrid BCP. The carbohydrate-inorganic hybrid BCPs were synthesized via a click reaction between oligodimethylsiloxane with an azido group at each chain end and propargyl-functionalized maltooligosaccharide (consisting of one, two, and three glucose units). In the bulk state, small-angle X-ray scattering revealed that these BCPs microphase separated into gyroid, asymmetric lamellar, and symmetric lamellar structures with domain-spacing ranging from 5.0 to 5.9 nm depending on the volume fraction. Additionally, we investigated microphase-separated structures in the thin film state and discovered that the BCP with the most asymmetric composition formed an ultrafine and highly oriented gyroid structure as well as in the bulk state. After reactive ion etching, the gyroid thin film was transformed into a nanoporous-structured gyroid SiO2 material, demonstrating the material's promising potential as nanotemplates.

| S-EPMC9144075 | biostudies-literature

Core-shell Structure and Aggregation Number of Micelles Composed of Amphiphilic Block Copolymers and Amphiphilic Heterografted Polymer Brushes Determined by Small-Angle X-ray Scattering.

Project description:A large group of functional nanomaterials employed in biomedical applications, including targeted drug delivery, relies on amphiphilic polymers to encapsulate therapeutic payloads via self-assembly processes. Knowledge of the micelle structures will provide critical insights into design of polymeric drug delivery systems. Core-shell micelles composed of linear diblock copolymers poly(ethylene glycol)-b-poly(caprolactone) (PEG-b-PCL), poly(ethylene oxide)-b-poly(lactic acid) (PEG-b-PLA), as well as a heterografted brush consisting of a poly(glycidyl methacrylate) backbone with PEG and PLA branches (PGMA-g-PEG/PLA) were characterized by dynamic light scattering (DLS) and small angle X-ray scattering (SAXS) measurements to gain structural information regarding the particle morphology, core-shell size, and aggregation number. The structural information at this quasi-equilibrium state can also be used as a reference when studying the kinetics of polymer micellization.

| S-EPMC5749421 | biostudies-literature

Polymer Brushes via Surface-Initiated Electrochemically Mediated ATRP: Role of a Sacrificial Initiator in Polymerization of Acrylates on Silicon Substrates.

Project description:Silicon wafers as semiconductors are essential components of integrated circuits in electronic devices. For this reason, modification of the silicon surface is an important factor in the manufacturing of new hybrid materials applied in micro- and nanoelectronics. Herein, copolymer brushes of hydrophilic poly(2-hydroxyethyl acrylate) (PHEA) and hydrophobic poly(tert-butyl acrylate) (PtBA) were grafted from silicon wafers via simplified electrochemically mediated atom transfer radical polymerization (seATRP) according to a surface-initiated approach. The syntheses of PHEA-b-PtBA copolymers were carried out with diminished catalytic complex concentration (successively 25 and 6 ppm of Cu). In order to optimize the reaction condition, the effect of the addition of a supporting electrolyte was investigated. A controlled increase in PHEA brush thickness was confirmed by atomic force microscopy (AFM). Various other parameters including contact angles and free surface energy (FSE) for the modified silicon wafer were presented. Furthermore, the effect of the presence of a sacrificial initiator in solution on the thickness of the grafted brushes was reported. Successfully fabricated inorganic-organic hybrid nanomaterials show potential application in biomedicine and microelectronics devices, e.g., biosensors.

| S-EPMC7475859 | biostudies-literature

Polymer tube nanoreactors via DNA-origami templated synthesis.

Project description:We describe the stepwise synthesis of precise polymeric objects programmed by a 3D DNA tube transformed from a common 2D DNA tile as a precise biotemplate for atom transfer radical polymerization. The catalytic interior space of the DNA tube was utilized for synthesizing a bio-inspired polymer, polydopamine.

| S-EPMC5885267 | biostudies-other

Quantifying Strain via Buckling Instabilities in Surface Modified Polymer Brushes.

Project description:A compressive strain applied to bilayer films (e.g. thin film adhered to a thick substrate) can lead to buckled or wrinkled morphologies, which has many important applications in stretchable electronics, anti-counterfeit technology, and high-precision micro and nano-metrology. A number of buckling-based metrology methods have been developed to quantify the residual stress and viscoelastic properties of polymer thin films. However, in some systems (e.g. solvent-induced swelling or thermal strain), the compressive strain is unknown or difficult to measure. We present a quantitative method of measuring the compressive strain of wrinkled polymer films and coatings with knowledge of the "skin" thickness, wrinkle wavelength, and wrinkle amplitude. The derived analytical expression is validated with a well-studied model system, e.g., stiff, thin film (PS) bonded to a thick, compliant substrate (PDMS). After validation, we use our expression to quantify the applied swelling strain of previously reported wrinkled poly(styrene-alt-maleic anhydride) brush surfaces. Finally, the applied strain is used to rationalize the observed persistence length of aligned wrinkles created during atomic force microscopy (AFM) lithography and subsequent solvent exposure.

| S-EPMC7580055 | biostudies-literature

Antifouling Polymer Brushes via Oxygen-Tolerant Surface-Initiated PET-RAFT.

Project description:This work presents a new method for the synthesis of antifouling polymer brushes using surface-initiated photoinduced electron transfer-reversible addition-fragmentation chain-transfer polymerization with eosin Y and triethanolamine as catalysts. This method proceeds in an aqueous environment under atmospheric conditions without any prior degassing and without the use of heavy metal catalysts. The versatility of the method is shown by using three chemically different monomers: oligo(ethylene glycol) methacrylate, N-(2-hydroxypropyl)methacrylamide, and carboxybetaine methacrylamide. In addition, the light-triggered nature of the polymerization allows the creation of complex three-dimensional structures. The composition and topological structuring of the brushes are confirmed by X-ray photoelectron spectroscopy and atomic force microscopy. The kinetics of the polymerizations are followed by measuring the layer thickness with ellipsometry. The polymer brushes demonstrate excellent antifouling properties when exposed to single-protein solutions and complex biological matrices such as diluted bovine serum. This method thus presents a new simple approach for the manufacturing of antifouling coatings for biomedical and biotechnological applications.

| S-EPMC7191748 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data