scholarly journals EVALUATION OF THIN FILM COMPOSITE FORWARD OSMOSIS MEMBRANES: EFFECT OF POLYMER TYPE

2021 ◽  
Vol 25 (6) ◽  
pp. 65-73
Author(s):  
Aya M. Kadhum ◽  
◽  
Mustafa H. Al-Furaiji ◽  
Zaidun N. Abudi ◽  
◽  
...  
Keyword(s):  
Water Flux ◽  
Forward Osmosis ◽  
Test Results ◽  
Semipermeable Membranes ◽  
Sem Images ◽  
Force Microscopy ◽  
Atomic Force ◽  
Energy Dispersion Spectrometry ◽  
Membrane Contact ◽  
Polymer Type

In the forward osmosis (FO) processes, the semipermeable membranes are used. These membranes are prepared from several types of polymers. In this research, the characterizations of each polymer were studied to conversance the effect of polymer type on the efficiency of the forward osmosis process. The prepared membrane’s roughness was investigated using atomic force microscopy (AFM) and scanning electron microscopy (SEM) to compare the formation of the TFC polyamide selective layer on each polymer type. Also, SEM images showed the distribution of pores on the prepared membrane. Contact angle (CA) measurements explained the hydrophilic and hydrophobic properties of membrane types. Finally, Energy dispersion spectrometry (EDS) was tested to determine the type, amount, and distribution of atoms in the prepared membranes. All of these characterizations proved that the Polysulfone (PSU) polymer was the best choice in the FO process. It can be proved that by test results, the PSU membrane gave the optimal water flux and salt rejection.

scholarly journals EVALUATION OF BACTERIAL CELLULOSE-SODIUM ALGINATE FORWARD OSMOSIS MEMBRANE FOR WATER RECOVERY

2018 ◽  
Vol 80 (3-2) ◽  
Author(s):  
Ngan T. B. Dang ◽  
Liza B. Patacsil ◽  
Aileen H. Orbecido ◽  
Ramon Christian P. Eusebio ◽  
Arnel B. Beltran
Keyword(s):  
Contact Angle ◽  
Bacterial Cellulose ◽  
Sodium Alginate ◽  
Water Flux ◽  
Forward Osmosis ◽  
Composite Membranes ◽  
Membrane Thickness ◽  
Water Recovery ◽  
Sem Images ◽  
Salt Rejection

Water resources are very important to sustain life. However, these resources have been subjected to stress due to population growth, economic and industrial growth, pollution and climate change. With these, the recovery of water from sources such as wastewater, dirty water, floodwater and seawater is a sustainable alternative. The potential of recovering water from these sources could be done by utilizing forward osmosis, a membrane process that exploits the natural osmotic pressure gradient between solutions which requires low energy operation. This study evaluated the potential of forward osmosis (FO) composite membranes fabricated from bacterial cellulose (BC) and modified with sodium alginate. The membranes were evaluated for water flux and salt rejection. The effect of alginate concentrations and impregnation temperatures were evaluated using 0.6 M sodium chloride solution as feed and 2 M glucose solution as the draw solution. The membranes were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Contact Angle Meter (CAM). The use of sodium alginate in BC membrane showed a thicker membrane (38.3 μm to 67.6 μm), denser structure (shown in the SEM images), and more hydrophilic (contact angle ranges from 28.39° to 32.97°) compared to the pristine BC membrane (thickness = 12.8 μm and contact angle = 66.13°). Furthermore, the alginate modification lowered the water flux of the BC membrane from 9.283 L/m2-h (LMH) to value ranging from 2.314 to 4.797 LMH but the improvement in salt rejection was prominent (up to 98.57%).

scholarly journals Estimating Step Heights from Top-Down SEM Images

2019 ◽  
Vol 25 (4) ◽  
pp. 903-911 ◽  
Author(s):  
Kerim Tugrul Arat ◽  
Jens Bolten ◽  
Aernout Christiaan Zonnevylle ◽  
Pieter Kruit ◽  
Cornelis Wouter Hagen
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Semiconductor Industry ◽  
Step Edge ◽  
Step Height ◽  
Top Down ◽  
Sem Images ◽  
Force Microscopy ◽  
Atomic Force ◽  
Primary Electrons

AbstractScanning electron microscopy (SEM) is one of the most common inspection methods in the semiconductor industry and in research labs. To extract the height of structures using SEM images, various techniques have been used, such as tilting a sample, or modifying the SEM tool with extra sources and/or detectors. However, none of these techniques focused on extraction of height information directly from top-down images. In this work, using Monte Carlo simulations, we studied the relation between step height and the emission of secondary electrons (SEs) resulting from exposure with primary electrons at different energies. It is found that part of the SE signal, when scanning over a step edge, is determined by the step height rather than the geometry of the step edge. We present a way to quantify this, arriving at a method to determine the height of structures from top-down SEM images. The method is demonstrated on three different samples using two different SEM tools, and atomic force microscopy is used to measure the step height of the samples. The results obtained are in qualitative agreement with the results from the Monte Carlo simulations.

scholarly journals Fabrication of a novel cyanoethyl cellulose substrate for thin-film composite forward osmosis membrane

2019 ◽  
Vol 1 (1) ◽  
pp. 18-32 ◽  
Author(s):  
Ke Zheng ◽  
Shaoqi Zhou
Keyword(s):  
Thin Film ◽  
Water Flux ◽  
Forward Osmosis ◽  
Feed Solution ◽  
Salt Flux ◽  
Sem Images ◽  
Film Composite ◽  
Thin Film Composite ◽  
Reverse Salt Flux ◽  
Cyanoethyl Cellulose

Abstract In this study, cyanoethyl cellulose (CEC) was used as a membrane material, and polyvinylpyrrolidone (PVP) was used as pore-forming agent to prepare the substrates for the thin-film composite (TFC) forward osmosis (FO) membrane for the first time. The experimental results demonstrate that the properties of the substrates were significantly improved after PVP was added. The scanning electron microscope (SEM) images show that a two-sublayer structure, a fringe-like top sublayer and macrovoids with sponge-like wall bottom sublayer, were formed after the addition of PVP. These improvements contributed to improved membrane performance during FO tests. Meanwhile, after adding PVP, the TFC membranes exhibited good water flux, and excellent specific reverse salt flux. For instance, the TFC-M2 exhibited 9.10/20.67 LMH water flux, 1.35/2.24 gMH reverse salt flux, and 0.15/0.11 g/L specific reverse salt flux in FO/pressure-retarded osmosis mode while using 1 M NaCl as the draw solution and deionized (DI) water as the feed solution.

Structural and mechanical properties of tantalum thin films ected by nitrogen ion implantation

2020 ◽  
Vol 34 (15) ◽  
pp. 2050163 ◽  
Author(s):  
A. H. Ramezani ◽  
S. Hoseinzadeh ◽  
Zh. Ebrahiminejad
Keyword(s):  
Friction Coefficient ◽  
Wear Mechanism ◽  
Mechanism Study ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Force Microscopy ◽  
Atomic Force ◽  
Coefficient Measurement ◽  
Nitrogen Ions ◽  
Nitrogen Ion

Tantalum bulk were implanted with nitrogen ions at different dose of [Formula: see text] ions/cm2 to [Formula: see text] ions/cm2 and at a energy 30 keV. The implanted samples were characterized using X-ray diffraction (XRD), atomic force microscopy (AFM), microhardness testing, friction coefficient measurements and wear mechanism study. Scanning electron microscopy (SEM) images were used to analyze the friction of samples. The XRD results confirmed that the increasing dose affects the formation of the TaN phase. Based on AFM images, the morphology and surface roughness change proportionally to grain size after implantation. It was found that hardness increases as energy increases. From the friction coefficient measurement, this coefficient decreases as energy increases. For the un-implanted sample, the wear mechanism has abrasion, and with increasing the energy, it shifts to being flake and sticky.

Optical and Structural Properties of Fluorine Doped SnO2 on Si (100) for Photovoltaic Application

2018 ◽  
Vol 13 (10) ◽  
pp. 1522-1532 ◽  
Author(s):  
S. Nivetha ◽  
K. Kaviyarasu ◽  
A. Ayeshamariam ◽  
N. Punithavelan ◽  
R. Perumalsamy ◽  
...  
Keyword(s):  
Spray Pyrolysis Technique ◽  
Energy Difference ◽  
Vital Role ◽  
X Ray Diffraction ◽  
Energy Storage Devices ◽  
Sem Images ◽  
Storage Devices ◽  
Force Microscopy ◽  
Photovoltaic Application ◽  
Atomic Force

Photovoltaic material plays a vital role in the production of energy storage devices, more specifically in solar cell fabrications. In this work, ITO:F-doped materials were coated over the silicon substrate through spray pyrolysis technique. X-ray diffraction studies were conducted for porous silicon (PSi) coated with ITO:F structures formed at different current densities. This pore formation is evident from the broad peak at 69.9°, revealing an amorphous-like nature but at the same location where the single crystalline peak also is observed. These pores are explicitly shown in the SEM images in which very fine surface fragments are observed. At 20 mA/cm2, well-defined porous patterns that were uniformly distributed over the surface were observed. The microstructures observed via atomic force microscopy for these PSi coated with ITO:F structures are randomly aligned and almost evenly distributed over the entire surface of these nanorods, which are approximately 40 nm. Radiative recombination of electrons from a level in the conduction band or its subband to a level at an energy difference of greater than 1.7 eV in the valance band or its subband will emit visible light.

scholarly journals Self-Assembly of Rice Bran Globulin Fibrils in Electrostatic Screening: Nanostructure and Gels

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Lihua Huang ◽  
Yehui Zhang ◽  
Haibin Li
Keyword(s):  
Ionic Strength ◽  
Rice Bran ◽  
Self Assembly ◽  
Gel Properties ◽  
Sem Images ◽  
Force Microscopy ◽  
Atomic Force ◽  
Repulsive Forces ◽  
Low Ionic Strength ◽  
Kinetics Of

The effects of various ionic strengths and protein concentrations on the fibrils structure and gel properties of rice bran globulin (RBG) at pH 2.0 were investigated using atomic force microscopy (AFM), rheometer, and scanning electron microscope (SEM). AFM images showed the morphology of assembling RBG fibrils from strand beads to becoming branch clustered, when electrostatic repulsive forces attenuated gradually with increasing ionic strength. NaCl seems to accelerate the kinetics of fibrils formation, resulting in a significant increase in Th T fluorescence intensity. The increased ionic strengths promote particle size increasing and zeta potential decreasing synchronously. The percolation modelG'~C-Cpnbe used to calculate theoretical RBG gels concentration at various ionic strengths (0–500 mM), which decreased from 15.17 ± 0.63 to 2.26 ± 0.27 wt%. SEM images exhibited a granular mesh-like gel structure. A more homogenous structure occurred in low ionic strength. This study elucidates properties of RBG fibrils and gels as a bioactive material.

scholarly journals Structural and Morphological Properties of As-Deposited and Heat Treated Blended Graphene Oxide / Poly(3,4-Ethylenedioxythiophene)-Poly(Styrenesulfonate) Thin Films

2021 ◽  
pp. 4416-4424
Author(s):  
Saja Qasim ◽  
Ameer F. AbdulAmeer ◽  
Ali H A Jalaukhan
Keyword(s):  
Thin Films ◽  
Graphene Oxide ◽  
Xrd Analysis ◽  
Morphological Properties ◽  
Sem Images ◽  
Force Microscopy ◽  
Atomic Force ◽  
Heat Treated ◽  
Spin Coater

    In this study the as-deposited and heat treated at 423K of conductive blend graphene oxide (GO)/ poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) thin films was prepared with different PEDOT:PSS concentration (0, 0.25, 0.5, 0.75 and 1)w/w on pre-cleaned glass substrate by spin coater. The XRD analysis indicate the existence of the preffered peak (001) of GO around 2θ=8.24° which is domain in all GO/ PEDOT:PSS films characterized for GO, this result approve the good quality of the PEDOT:PSS dispersion in GO, this peak shifted to the lower 2θ with increasing PEDOT:PSS concentration and after annealing process. The scanning electron microscopy (SEM) images and atomic force microscopy (AFM) clearly show the GO flakes and go to disappear with increasing the PEDOT:PSS concentration. 

Synthesis and Characterization of CTA/CA-Based Forward Osmosis Membranes with Hydrophilic Nano-Titanium Dioxide

2016 ◽  
Vol 867 ◽  
pp. 127-131 ◽  
Author(s):  
Xiu Ju Wang ◽  
Xin Lian Shi ◽  
Shu Fang Hou ◽  
Jian Hua Yang ◽  
Kai Li Zhou ◽  
...  
Keyword(s):  
Pure Water ◽  
Water Flux ◽  
Forward Osmosis ◽  
Bath Temperature ◽  
High Water ◽  
Cellulose Triacetate ◽  
Sem Images ◽  
Salt Rejection ◽  
Pure Water Flux ◽  
Nano Titanium Dioxide

In this paper, a novel nanocomposite forward osmosis membrane (nTiO2-CTA/CA) was fabricated by introducing nanotitaniumdi oxide (nTiO2) into the cellulose triacetate/cellulose acetate (CTA/CA)-based casting solution using phase inversion methods. Casting composite and preparation--nTiO2 content, blend temperature and coagulating bath temperature--were tested for their effects on pure water flux and salt rejection of membranes. Results revealed that the FO membrane prepared under optimized composition showed excellent desalination performance (high water flux = 5.38 L/m2·h and salt rejection > 97 %). Moreover, SEM images showed that addition of nTiO2 resulted in nanocomposite forward osmosis membrane with a smoother surface. The contact angle of the membranes decreased from 76o to 51° with increase nTiO2 concentration from 0% to 0.10%.

Nanoscale Investigation of Nb-Doped CaCu3Ti4O12 Grains

2011 ◽  
Vol 364 ◽  
pp. 455-459 ◽  
Author(s):  
Muhammad Azwadi Sulaiman ◽  
Sabar Derita Hutagalung ◽  
Zainal Arifin Ahmad
Keyword(s):  
Domain Boundary ◽  
Domain Size ◽  
Solid State Reaction Method ◽  
Sem Images ◽  
Force Microscopy ◽  
Atomic Force ◽  
Device Applications ◽  
Nanoscale Imaging ◽  
High Dielectric ◽  
Sem Analyses

CaCu3Ti4O12 (CCTO) is a promising material for microelectronic and microwave device applications due to its unique properties that posses high dielectric constant in the wide temperature range. In this work, atomic force microscopy (AFM) and scanning electron microscopy (SEM) analyses were applied for nanoscale imaging of Nb-doped CCTO grains. The Nb-doped CCTO pellets (CaCu3Ti4-xNbxO12+x/2; x = 0, 0.01, 0.03, 0.05, 0.1) were prepared via solid state reaction method and thermally etched at 940°C for an hour. From AFM and SEM images found that tiny bumped as well as terrace type domains are distributed within a grain. The domain size is ranging from 20 to 180 nm measured by AFM. The existence of domains on grain will produce grain boundary and domain boundary resistance inside CCTO. Both domain and grain resistance are believed to strongly influence the electrical properties of CCTO.

scholarly journals Micro/Nanoscale Study on the Effect of Aging on the Performance of Crumb Rubber Modified Asphalt

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Lan Wang ◽  
Yang Liu ◽  
Le Zhang
Keyword(s):  
Molecular Dynamics ◽  
Crumb Rubber ◽  
Dynamics Simulation ◽  
Surface Microstructure ◽  
Test Results ◽  
Force Microscopy ◽  
Modified Asphalt ◽  
Atomic Force ◽  
Before And After ◽  
Microscopic Surface

In order to explore the variation of crumb rubber modified asphalt (CR) before and after aging at the micro- and nanoscales, the molecular dynamics simulation and atomic force microscopy (AFM) asphalt microstructure scanning were carried out on CR before and after aging. The molecular dynamics energy, radial distribution function (RDF), surface microstructure image, roughness, and other test results of the CR before and after aging were compared and analyzed. The results show that the molecular dynamic energy of the CR after aging increases; the asphaltene-asphaltene RDF is decreased after aging; and the AFM surface microstructure images of asphalt before and after aging do not change significantly, but quantitative analysis by roughness theory shows that aging makes the microscopic surface of the CR more uniform and gentle. By analyzing the changes of asphalt properties before and after aging at two scales, it can be found that there is a certain relationship between the properties obtained at different scales. The reasons and mechanisms for the influence of microstructure on aging are obtained by analyzing this relationship.

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