scholarly journals Characterization of Strong and Crystalline Polyvinyl Alcohol/Montmorillonite Films Prepared by Layer-by-Layer Deposition Method

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
S. Gaidukov ◽  
I. Danilenko ◽  
G. Gaidukova
Keyword(s):  
Polyvinyl Alcohol ◽  
Thermal Studies ◽  
High Strength ◽  
Film Structure ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Atomic Force ◽  
Layer Deposition

The preparation of a high-strength and highly crystalline nanocomposite with a layered structure by the use of layer-by-layer deposition (LbL) method from polyvinyl alcohol (PVOH) and montmorillonite (MMT) platelets is reported. The crystallinity and interactions between the components were studied by the use of Fourier transform infrared spectroscopy (FT-IR), wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The nanocomposite film structure was investigated by the use of scanning electron microscope (SEM) and atomic force microscopy (AFM). The stiffness of the LbL PVOH/MMT film was significantly higher compared to pure PVOH and conventional PVOH/MMT nanocomposite. The structural and thermal studies on thin PVOH/MMT films indicated the enhanced crystallinity of the polymer.

scholarly journals Probing surface interactions of underwater oleophobic polyelectrolyte multilayers

2020 ◽  
Author(s):  
Kai Li ◽  
Wei Wang ◽  
Zhi-Peng Yu ◽  
Hang Jin ◽  
Yun-Tong Ge ◽  
...  
Keyword(s):  
Theoretical Calculations ◽  
Interaction Mechanism ◽  
Polyelectrolyte Multilayers ◽  
Layer By Layer ◽  
Surface Wetting ◽  
Force Microscopy ◽  
Atomic Force ◽  
Layer Deposition ◽  
Nacl Concentration ◽  
Force Curves

Abstract In the present work, the interaction mechanism of specific polyelectrolyte multilayers (PEMs), fabricated by layer-by-layer deposition of polydiallyldimethylammonium chloride (PDDA) and poly(sodium 4-styrenesulfonate) (PSS), is studied using atomic force microscopy. The underwater oil-repellency of PSS-capped PEMs was further explored by measuring the interaction forces between tetradecane droplets and PEMs-coated silica substrates under various salinities. The force curves were analyzed following the Stokes–Reynolds–Young–Laplace theoretical model. Desirable consistency was achieved between the experimental and theoretical calculations at low NaCl concentrations (0.1 mM and 1 mM); however, underestimation of the attractive force was found as the NaCl concentration increases to moderate (10 mM) and high (100 mM) levels. Discrepancy analyses and incorporated features toward a reduced surface charge density were considered based on the previous findings of the orientation of anionic benzenesulfonate moieties (Liu et al. in Angew Chem Int Ed 54(16):4851–4856, 2015. https://doi.org/10.1002/anie.201411992). Short-range steric hindrance interactions were further introduced to simulate “brush” effect stemming from nanoscale surface roughness. It is demonstrated in our work that the PSS-capped PEMs remains a stable underwater lipophobicity against high salinity, which renders it potential application in surface wetting modification and anti-fouling.

scholarly journals New thermoplastic poly(carbonate-urethane) elastomers

2011 ◽  
Vol 13 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Anna Kultys ◽  
Magdalena Rogulska
Keyword(s):  
Soft Segment ◽  
Tensile Tests ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Melt Polymerization ◽  
Atomic Force ◽  
Amorphous Structures ◽  
A Chain ◽  
Poly Carbonate

New thermoplastic poly(carbonate-urethane) elastomersTwo series of novel thermoplastic poly(carbonate-urethane) elastomers, with different hard-segment content (30 - 60 wt %), were synthesized by melt polymerization from poly(hexane-1,6-diyl carbonate) diol of Mn= 2000 as a soft segment, 4,4'-diphenylmethane diisocyanate (MDI) or hexane-1,6-diyl diisocyanate (HDI) and 6,6'-[methylenebis(1,4-phenylenemethylenethio)]dihexan-1-ol as a chain extender. The structure and basic properties of the polymers were examined by Fourier transform infrared spectroscopy, X-ray diffraction analysis, atomic force microscopy, differential scanning calorimetry, thermogravimetric analysis, Shore hardness and tensile tests. The resulting TPUs were colorless polymers, showing almost amorphous structures. The MDI-based TPUs showed higher tensile strengths (up to 21.3 MPa vs. 15.8 MPa) and elongations at break (up to 550% vs. 425%), but poorer low-temperature properties than the HDI-based analogs.

STUDIES ON SURFACE STRUCTURE, MORPHOLOGY AND COMPOSITION OF Co–W COATINGS ELECTRODEPOSITED WITH DIRECT AND PULSE CURRENT USING GLUCONATE BATH

2013 ◽  
Vol 20 (01) ◽  
pp. 1350006 ◽  
Author(s):  
PARTHASARATHI BERA ◽  
H. SEENIVASAN ◽  
K. S. RAJAM
Keyword(s):  
Photoelectron Spectroscopy ◽  
Pulse Current ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Force Microscopy ◽  
Dsc Studies ◽  
Atomic Force ◽  
Electrodeposited Coating

Co–W alloy coatings were deposited with direct current (DC) and pulse current (PC) electrodeposition methods using gluconate bath at pH5 and characterized by X-ray diffraction, field emission scanning electron microscopy, atomic force microscopy, differential scanning calorimetry (DSC) and X-ray photoelectron spectroscopy (XPS). DSC studies hint at the possibility of formation of metallic glasses. Detailed XPS studies of these alloy coatings have been carried out to compare elemental states and composition of Co and W in DC and PC electrodeposited alloys. DC-plated alloy has significant amount of Co and W metal along with their respective oxidized species. In contrast, mainly oxidized metals are present in the following layers of as-deposited coatings prepared with PC plating. Concentration of Co metal is observed to increase during sputtering, whereas there is no change in W6+ concentration. Microhardness measurement of all the Co–W coatings shows higher hardness compared to Co metal and 1:1 and 1:4 PC electrodeposited coatings show little higher hardness compared to 1:2 PC electrodeposited coating.

Characterization of nano-structured poly(ε-caprolactone) membranes with DNA-doped polypyrrole via sonication-induced layer-by-layer assembly

2018 ◽  
Vol 89 (7) ◽  
pp. 1267-1275
Author(s):  
Geon Jin Kim ◽  
Kee Jong Yoon ◽  
Ick Soo Kim ◽  
Kyu Oh Kim
Keyword(s):  
Contact Angle ◽  
Fiber Diameter ◽  
Good Survival ◽  
Cytotoxicity Test ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Layer By Layer Assembly ◽  
Layer Assembly

In this study, the formation of conductive nano-structured polypyrrole (PPy) on electrospun poly(ɛ-caprolactone) (PCL) nanofibers was successfully achieved using a DNA dopant (PCL/DNA-PPy) via sonication-induced layer-by-layer assembly. After PPy containing positive charges was accumulated on PCL, DNAs with negative charges deposited such that they were evenly distributed. The resulting PCL/DNA-PPy nanomembrane exhibited increased fiber diameter (PCL/DNA-PPy 5LBL: 328.11 ± 48 nm) and deformation morphology compared to pure PCL (average fiber diameter of 247.25 ± 32 nm, fibrous uniform morphology), as observed using scanning electron microscopy and atomic force microscopy. As the number of layers increased, the crystallinity of PCL/DNA–PPy nanomembranes decreased, as observed using X-ray diffraction. It was observed that the PPy-DNA deposited on the surface of PCL connected to form a nano-sheath and significantly increased the thermal stability of PCL. Moreover, the contact angle of the PCL/DNA-PPy nanomembrane (contact angle of pure PCL: 79.3 ± 1.2°) demonstrated its high hydrophilicity. The results indicate that the composites showed very good survival in a cytotoxicity test on U-118 glioma cells and excellent electrical conductivity (the highest value was 1.1 × 10−3 S/m). The manufactured PCL/DNA–PPy nanomembranes are considered to be promising materials for applications in the scaffold, sensor, and electronic fields.

scholarly journals Preparation of (Pb,Ba)TiO3 powders and highly oriented thin films by a sol-gel process

2004 ◽  
Vol 19 (5) ◽  
pp. 1492-1498 ◽  
Author(s):  
Stacey W. Boland ◽  
Suresh C. Pillai ◽  
Wein-Duo Yang ◽  
Sossina M. Haile
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Chelating Agent ◽  
Titanium Isopropoxide ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Molar Ratios ◽  
Atomic Force ◽  
Sol Gel Process

Solid solution Pb1-xBaxTiO3, with particular emphasis on Pb0.5Ba0.5TiO3, was prepared using a sol-gel process incorporating lead acetate trihydrate, barium acetate, and titanium isopropoxide as precursors, acetylacetone (2,4 pentanedione) as a chelating agent, and ethylene glycol as a solvent. The synthesis procedure was optimized by systematically varying acetylacetone: Ti and H2O:Ti molar ratios and calcination temperature. The resulting effects on sol and powder properties were studied using thermogravimetric analysis/differential scanning calorimetry, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller analysis, and x-ray diffraction (XRD). Crystallization of the perovskite structure occurred at a temperature as low as 450 °C. Thin films were prepared by spin coating on (100) MgO. Pyrolysis temperature and heating rate were varied, and the resultant film properties investigated using field-emission scanning electron microscopy, atomic force microscopy, and XRD. Under optimized conditions, highly oriented films were obtained at a crystallization temperature of 600 °C.

scholarly journals Epitaxial Stabilization of Single-Crystal Multiferroic YCrO3 Thin Films

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 2085
Author(s):  
Yogesh Sharma ◽  
Elizabeth Skoropata ◽  
Binod Paudel ◽  
Kyeong Tae Kang ◽  
Dmitry Yarotski ◽  
...  
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Magnetic Transition ◽  
Close Correlation ◽  
Layer By Layer ◽  
Epitaxial Thin Films ◽  
X Ray Diffraction ◽  
Magnetic Transition Temperature ◽  
Force Microscopy ◽  
Atomic Force

We report on the growth of stoichiometric, single-crystal YCrO3 epitaxial thin films on (001) SrTiO3 substrates using pulsed laser deposition. X-ray diffraction and atomic force microscopy reveal that the films grew in a layer-by-layer fashion with excellent crystallinity and atomically smooth surfaces. Magnetization measurements demonstrate that the material is ferromagnetic below 144 K. The temperature dependence of dielectric permittivity shows a characteristic relaxor-ferroelectric behavior at TC = 375–408 K. A dielectric anomaly at the magnetic transition temperature indicates a close correlation between magnetic and electric order parameters in these multiferroic YCrO3 films. These findings provide guidance to synthesize rare-earth, chromite-based multifunctional heterostructures and build a foundation for future studies on the understanding of magnetoelectric effects in similar material systems.

Preparation of (111)-Oriented Pt Electrode Films with Quasi-Monocrystal Properties on MgO/TiN Buffered Si(100) by PLD

2007 ◽  
Vol 280-283 ◽  
pp. 823-826 ◽  
Author(s):  
Tong Lai Chen ◽  
Xiao Min Li
Keyword(s):  
High Energy ◽  
Layer Growth ◽  
Atomic Scale ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Pt Electrode ◽  
Force Microscopy ◽  
Atomic Force

Atomic-scale smooth Pt electrode films have been deposited on MgO/TiN buffered Si (100) by the pulsed laser deposition (PLD) technique. The whole growth process of the multilayer films was monitored by using in-situ reflection high energy electron diffraction (RHEED) apparatus. The Pt/MgO/TiN/Si(100) stacked structure was also characterized by X-ray diffraction (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM). The HREED observations show that the growth mode of the Pt electrode film is 2D layer-by-layer growth. It is found that the (111)-oriented Pt electrode film has a crystallinity comparable to that of monocrystals. The achievement of the quasi-single-crystal Pt electrode film with an atomic-scale smooth surface is ascribed to the improved crystalline quality of the MgO film.

Nanoindention studies of DC sputtered Cu and Cu/Cr thin films

2001 ◽  
Vol 672 ◽  
Author(s):  
G. Wei ◽  
J. Du ◽  
A. Rar ◽  
J. A. Barnard
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Grain Size ◽  
Surface Morphology ◽  
Film Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Grain Size And Orientation

ABSTRACTThe nanoindentation behavior of DC magnetron sputtered 10 nm Cu and 10 nm Cu/2 nm Cr thin films deposited on Si (100) has been studied using a Hysitron nanomechanical system. X- ray diffraction and X-ray reflectivity were used to measure the film structure and film thickness, respectively. The grain size and orientation of Cu and Cu/Cr thin films were measured by TEM. Atomic force microscopy (AFM) was used to evaluate the surface morphology and roughness. At the same load, the nanoindentaion displacement of Cu/Cr is smaller than that for Cu, i.e., the 2nm thick Cr underlayer enhances the hardness of Cu. X-ray, TEM, and AFM results show that the grain size of Cu/Cr (< 15 nm) is actually larger than Cu (∼ 3 nm) indicating that the inverse Hall-Petch relationship may be operative.

Investigation of electrical properties of peald-deposited Ti/Al2O3/Al/Si MIM capacitors

2021 ◽  
pp. 2140045
Author(s):  
Sumit Patil ◽  
Viral Barhate ◽  
Ashok Mahajan ◽  
Haoyu Xu ◽  
Mohammad Rasadujjaman ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Atomic Layer ◽  
Stable Phase ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Layer Deposition ◽  
Current Voltage ◽  
Different Temperatures ◽  
Mim Capacitors

MIM devices fabricated with 10-nm thickness of Al2O3 high-[Formula: see text] thin film deposited using plasma-enhanced atomic layer deposition (PEALD) system on Al-coated Si substrate were investigated. The structural, morphological and electrical properties of Ti/Al2O3/Al/Si MIM capacitors as-deposited and post-deposition annealed (PDA) at different temperatures were studied and compared. Al2O3 thin films were investigated using atomic force microscopy (AFM) and X-ray diffraction (XRD) and Ti/Al2O3/Al/Si MIM capacitors were characterized by current–voltage ([Formula: see text]–[Formula: see text] and capacitance–voltage ([Formula: see text]–[Formula: see text] measurements. The stable phase formation of Ti/Al2O3/Al/Si MIM capacitor provides the lowest leakage current density in the range of nA/cm2 for as-deposited and annealed films.

Ultrathin Films of Oriented Bacteriorhodopsin: Nanostructured Films for Investigating the Primary Photoevent in Vision Processes

2001 ◽  
Vol 679 ◽  
Author(s):  
Rigoberto C. Advincula ◽  
Mi-kyoung Park
Keyword(s):  
Ultrathin Films ◽  
Supramolecular Assembly ◽  
Solid Substrate ◽  
Film Structure ◽  
Glass Electrode ◽  
Layer By Layer ◽  
Ph Change ◽  
Force Microscopy ◽  
Atomic Force ◽  
Substrate Surfaces

ABSTRACTIn this work, a protocol for investigating Bacteriorhodopsin (BR) biomimetic systems as ultrathin films is presented. BR is one of the most well studied proteins important for investigating the primary photo-event in vision processes. The use of macromolecular assembly approaches for deposition onto solid support substrates, e.g. SiOx, gold- or ITO-coated glass (electrode) provide advantages in that surface sensitive measurements can be used to correlate photocurrent generation, photoelectric response, pH change, chromophore behavior, etc. with protein orientation at interfaces. Membrane and protein morphology were correlated to measurements using surface sensitive techniques, such as atomic force microscopy (AFM), ellipsometry, quartz crystal microbalance (QCM), etc. on solid-substrate systems. These studies can lead to applications in optobioelectronic devices (biosensors) including patterning in transducer array configurations, where the film structure is important. Hybrid films are possible with supramolecular assembly approaches, e.g. adsorption of membrane with lipidbilayers. We report our initial results on highly ordered and oriented BR protein arrays of controlled thickness, layer order, and orientation. This was done primarily using the alternate polyelectrolyte deposition (APD) or layer-by-layer (LbL) approach to functionalize substrate surfaces.

Sign in / Sign up

Export Citation Format

Share Document