Study on Structure and Properties of Polysulfone Membranes Using Ionic Liquid [n-C16mim][BF4] as a New Structure-Controlled Additive

2013 ◽  
Vol 561 ◽  
pp. 125-129 ◽  
Author(s):  
Ying Ying Ding ◽  
Ya Mei Zhao ◽  
Chang Zheng Zheng ◽  
Dong Huai Tu
Keyword(s):  
Ionic Liquid ◽  
Cross Sections ◽  
Retention Rate ◽  
Contact Angles ◽  
Asymmetric Structure ◽  
Polysulfone Membrane ◽  
Force Microscopy ◽  
Wet Phase Inversion ◽  
Surface Morphologies ◽  
Polysulfone Membranes

Introducing ionic liquid [n-C16mim][BF4] as a new structure-controlled additive, Polysulfone (PSf) membranes were prepared by the wet-phase-inversion using [n-C16mim][BF4] into the casting solution (PSf/NMP). The scanning electron microscope and the atomic force microscopy were utilized to visualize the cross-sections of the membranes to gain more better understanding the structure-controlled ability of [n-C16mim][BF4] and surface morphologies of the membrane. The results indicate that the structures of the membranes were typical bilayer asymmetric finger-pores structure. [n-C16mim][BF4] has stronger ability of the pore-forming. Especially, at the 4:76 ratio of [n-C16mim][BF4]/NMP in the polymer solution ,the membrane has the asymmetric structure and good separation properties of the solution flux. The PSf membrane has the 0.45~0.65μm dimpling close to surface layer, and the retention rate and solution flux of the prepared membrane are 95.2% and 137.5 L•h-1•m-2. Meanwhile, [n-C16mim][BF4] partially retained in the prepared Polysulfone membrane reduced the contact angles of Polysulfone membranes, improving the hydrophilic properties of the membranes.

Preparation of Polysulfone Membranes Using Ionic Liquid [C16mim][SCN] as a Pore-Former and Plasticizer

2009 ◽  
Vol 87-88 ◽  
pp. 74-79 ◽  
Author(s):  
Ya Mei Zhao ◽  
Xiao Ling Hu ◽  
Jin Yang Yu ◽  
Ping Guan
Keyword(s):  
Ionic Liquid ◽  
Surface Layer ◽  
Thermal Properties ◽  
Cross Sections ◽  
Phase Inversion ◽  
Retention Rate ◽  
Pore Former ◽  
Forming Mechanism ◽  
Wet Phase Inversion ◽  
Scanning Electron

Polysulfone (PSf) membranes were prepared by the wet-phase-inversion using 1-hexadecyl-3-methylimidazolium thiocyanate [C16mim][SCN] as an new additive. Scanning electron microscope was utilized to visualize cross-sections of the membranes to gain more better understanding the influence of [C16mim][SCN] on the pore-forming. Moreover, Membrane-forming mechanism using ionic liquid as a pore-former was also discussed. The results showed that ionic liquid [C16mim][SCN] had restrained the demixing of the casting solutions and has the ability of the pore-forming, higher than those of its analogues of PEG400. With increase of concentration of ionic liquid [C16mim][SCN] in casting solutions, the structures of the membranes changed from asymmetric finger pores to the spongy-finger-macrovoid structure of the pores. Compared with PEG400 as a pore-former,[C16mim][SCN] has the pore-forming ability to the membrane at lower concentration of [C16mim][SCN] in the casting solution. Especially, at the 4:76 ratio of [C16mim][SCN]/NMP, the prepared membrane has the asymmetric finger-pores structure, with the 2~6μm pores close to surface layer and the 10~24μm pore for its sublayer. Its retention rate of PEG10000 and solution flux are 97.1% and 48.7 L• h-1• m-2. Meanwhile, ionic liquid can be a plasticizer, according the thermal properties of the membranes.

Surface Modification of Asymmetric Polysulfone Membrane by UV Irradiation

2014 ◽  
Vol 70 (2) ◽  
Author(s):  
Sutthisa Konruang ◽  
Thawat Chittrakarn ◽  
Suksawat Sirijarukul
Keyword(s):  
Contact Angle ◽  
Surface Modification ◽  
Functional Groups ◽  
Uv Irradiation ◽  
Water Flux ◽  
Inversion Method ◽  
Asymmetric Structure ◽  
Polysulfone Membrane ◽  
Polar Functional Groups ◽  
Polysulfone Membranes

The effects of ultraviolet (UV) irradiation for surface modification of hydrophobic asymmetric polysulfone membranes have been investigated. The asymmetric polysulfone (PSF) membranes were prepared by phase inversion method using 19%-25% of PSF in two solvents, viz. dimethylacetamide (DMF) and Acetone (Ac) collectively. The surface of asymmetric polysulfone membranes were modified by UV ray with 254 and 312 nm wavelength. Chemical and physical properties of the untreated and the treated membranes were characterized. Scanning electron microscope (SEM) was used to determine asymmetric structure of polysulfone membranes. Contact angle device was used to analyzed the effected of UV ray treatment on hydrophilicity of membranes surface. Polar functional groups introduced by UV irradiation were examined using FTIR. The water flux was measured under a pressure of 500 kPa to 2,500 kPa with a feed temperature of 25°C. It was shown that asymmetric polysulfone membranes were produced and the UV ray treatment significantly alters the hydrophilicity of membranes surface indicated by the reduction of water contact angle with increasing treatment time. The FTIR analysis showed the formations of polar functional groups such as hydroxyl and carbonyl groups. Consequently, the surface of asymmetric polysulfone membranes was changed from hydrophobic to hydrophilic by UV irradiation leading to the enhancement of the water flux.

Multitechnique characterization of polysulfone gas permeation membranes

1995 ◽  
Vol 53 ◽  
pp. 504-505
Author(s):  
M. A. Behrens ◽  
Y. H. R. Jois ◽  
P. L. Dahlstrom
Keyword(s):  
Cross Sections ◽  
Photoelectron Spectroscopy ◽  
Membrane Surface ◽  
Glass Plate ◽  
Gas Permeation ◽  
Chemical Information ◽  
Skin Thickness ◽  
Force Microscopy ◽  
Wet Phase Inversion ◽  
Thin Skin

Integrally thin skinned asymmetric polysulfone membranes developed for gas separation applications were prepared by casting a dope solution on a glass plate. A dry/wet phase inversion process with a forced convective evaporation step is then used to form a skin. The membrane is immersed in water before undergoing a solvent exchange and drying process. The thin skin of these membranes allows gas to selectively diffuse through the membrane when the surface is without defects. The gas transport properties (selectivity and flux) are measured using standard techniques and are reported on Table II.Scanning electron microscopy is an important method of examining the cross-sections and surfaces of these membranes to determine the surface integrity, skin thickness, and porosity of the supporting substructure. The ideal integrally thin skin thickness is 1000 Å or less. We further characterized these membranes using Atomic Force Microscopy to image the membrane surface and X-ray Photoelectron Spectroscopy to obtain chemical information about the polysulfone surface.

scholarly journals Effect of water on the electroresponsive structuring and friction in dilute and concentrated ionic liquid lubricant mixtures

2020 ◽  
Vol 22 (48) ◽  
pp. 28191-28201
Author(s):  
Georgia A. Pilkington ◽  
Rebecca Welbourn ◽  
Anna Oleshkevych ◽  
Seiya Watanabe ◽  
Patricia Pedraz ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Ionic Liquid ◽  
Neutron Reflectivity ◽  
Force Microscopy ◽  
Liquid Lubricant ◽  
Effect Of Water ◽  
Atomic Force ◽  
Ambient Levels

The influence of ambient levels of water on the electroresponsive interfacial structuring and nanofriction of ionic liquid lubricant mixtures has been investigated by neutron reflectivity and atomic force microscopy.

Properties of Yttrium Oxide Thin Films on Silicon (100) Prepared by Evaporation of Yttrium in Atomic Oxygen

1994 ◽  
Vol 341 ◽  
Author(s):  
J. Hudner ◽  
H. Ohlsén ◽  
E. Fredriksson
Keyword(s):  
Atomic Oxygen ◽  
Oxygen Plasma ◽  
Rutherford Backscattering Spectrometry ◽  
Thin Layers ◽  
Force Microscopy ◽  
Intermediate Layers ◽  
Activated Reactive Evaporation ◽  
Film Substrate ◽  
Surface Morphologies ◽  
Substrate Temperatures

AbstractThin layers of Y2O3 have been prepared on silicon (100) by an activated reactive evaporation process involving evaporation of metal Y in an atomic oxygen plasma. The presence of the oxygen plasma was found to be crucial for the formation of homogeneous Y2O3 films on Si. The formation of Y2O3 films on Si (100) at different substrate temperatures was investigated. X-ray diffraction analysis showed that Y2O3 films formed between 300 °C and 650 °C were (111) textured while Y2O3 prepared at lower substrate temperatures (80 °C) exhibited mixed orientations. Rutherford backscattering spectrometry indicated that films were stoichiometric. No pronounced channeling was observed in films grown at 350 °C, suggesting polycrystalline film structures. Atomic force microscopy revealed very smooth surface morphologies with average surface roughness < 20 Å for films 700 Å thick deposited at 350 °C. Secondary ion mass spectroscopy indicated the abundance of intermediate layers in the film-substrate interface.

Mechanical Interlocking on Leadframe Surface for Bondability of Au Wedge Bond

2016 ◽  
Vol 857 ◽  
pp. 79-82
Author(s):  
Roslina Ismail ◽  
Fuaida Harun ◽  
Azman Jalar ◽  
Shahrum Abdullah
Keyword(s):  
Optical Microscope ◽  
Bonding Process ◽  
Mechanical Interlocking ◽  
Average Roughness ◽  
Force Microscopy ◽  
Atomic Force ◽  
Surface Morphologies ◽  
Scanning Electron ◽  
Effect Of Surface

This work is a contribution towards the understanding of wire bond integrity and reliability in relation to their microstructural and mechanical properties in semiconductor packaging.The effect of surface roughness and hardness of leadframe on the bondability of Au wedge bond still requires detail analysis. Two type of leadframes namely leadframe A and leadframe B were chosen and scanning electron microscope (SEM) and optical microscope were used to inspect the surface morphology of leadframes and the quality of created Au wedge bond after wire bonding process. It was found that there were significant differences in the surface morphologies between these two leadframes. The atomic force microscopy (AFM) which was utilized to measure the average roughness, Ra of lead finger confirms that leadframe A has the highest Ra with value of 166.46 nm compared to that of leadframe B with value of 85.89 nm. While hardness value of different lead finger from the selected leadframe A and B obtained using Vicker microhardness tester are 180.9 VH and 154.2VH respectively.

scholarly journals Synthesis of amphiphilic ABA triblock oligomer via ATRP and its surface properties

2017 ◽  
Vol 95 (5) ◽  
pp. 605-611 ◽  
Author(s):  
Lei Wang ◽  
Shaoqing Wen ◽  
Zhanxiong Li
Keyword(s):  
Photoelectron Spectroscopy ◽  
Microphase Separation ◽  
Gel Permeation Chromatography ◽  
Contact Angles ◽  
Chemical Compositions ◽  
Water Contact ◽  
Force Microscopy ◽  
Atomic Force ◽  
Poly Ethylene ◽  
Magnetic Resonances

A series of novel amphiphilic ABA-type poly(tridecafluorooctylacrylate)-poly(ethylene glycol)-poly(tridecafluorooctylacrylate) (henceforth referred to as p-TDFA-PEG-p-TDFA) triblock oligomers were successfully synthesized via atom transfer radical polymerization (ATRP) using well-defined Br-PEG-Br as macroinitiator and copper as catalyst. The block oligomers were characterized by Fourier transform infrared (FTIR) spectroscopy and 1H and 19F nuclear magnetic resonances (NMR). Gel permeation chromatography (GPC) showed that the block oligomers have been obtained with narrow molecular weight distributions of 1.22–1.33. X-ray photoelectron spectroscopy (XPS) was carried out to confirm the attachment of p-TDFA-PEG-p-TDFA onto the silicon substrate, together with the chemical compositions of p-TDFA-PEG-p-TDFA. The wetabilities of the oligomer films were measured by water contact angles (CAs). Water CAs of p-TDFA-PEG-p-TDFA film were measured and their morphologies were tested by atomic force microscopy (AFM). The result showed that the CAs of the oligomer films, which possess fluoroalkyl groups assembled on the outer surface, increase after heating due to the migration of fluoroalkyl groups and the resulted microphase separation of the p-TDFA-PEG-p-TDFA.

scholarly journals Atomic Force Microscopy Applied to Atopic Dermatitis Study

2021 ◽  
Vol 18 (4) ◽  
pp. 21-28
Author(s):  
Simona Maria Ţîrcă ◽  
Ion Ţîrcă ◽  
Marius Sorin Ciontea ◽  
Florin Dumitru Mihălţan
Keyword(s):  
Atomic Force Microscopy ◽  
Atopic Dermatitis ◽  
Structural Integrity ◽  
Clinical Investigation ◽  
Normal Skin ◽  
Skin Lesions ◽  
Force Microscopy ◽  
Atomic Force ◽  
Child Patient ◽  
Surface Morphologies

Abstract Atopic dermatitis (AD)-the commonest inflammatory skin disease affects up to 25% of children and 2% to 5% of adults. Methods of the diagnostic provide expanded recommendations founded on available evidence. Morphological evaluation remains a principal feature of clinical investigation and the main criteria of diagnosis. Methods. We collected normal and affected skin from a 6-month child patient who was diagnosed through dermatologic examination. Clinical characteristics and the diagnosis of atopic dermatitis were in accordance with Hanifin and Rajka criteria. Morphology and structural integrity were investigated by Atomic Force Microscopy. Results. Optical and topography images indicate that in the case of AD skin lesions the cuticle structure was severely damaged and distorted with the flattening and grading of the plates, which have an irregular appearance. From the surface morphologies of the samples, we demonstrate that the shape of the corneocytes, with granular and elongated appearance, specific to normal skin is transformed by AD into broken and collapsed plates with discontinuous appearance. Conclusions. In the initial diagnosis of AD changes of the skin properties can be an indicator. Hanifin and Rajka criteria together with Atomic Force Microscopy can be a useful and necessary technique diagnosing cases of atopic dermatitis.

scholarly journals Electroresponsive structuring and friction of a non-halogenated ionic liquid in a polar solvent: effect of concentration

2020 ◽  
Vol 22 (34) ◽  
pp. 19162-19171 ◽  
Author(s):  
Georgia A. Pilkington ◽  
Anna Oleshkevych ◽  
Patricia Pedraz ◽  
Seiya Watanabe ◽  
Milad Radiom ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Ionic Liquid ◽  
Solvent Effect ◽  
Polar Solvent ◽  
Neutron Reflectivity ◽  
Force Microscopy ◽  
Frictional Properties ◽  
Atomic Force

Neutron reflectivity and atomic force microscopy results reveal the electroresponsive interfacial structuring and nano-frictional properties of ionic liquid (IL) lubricant mixtures with a polar solvent are strongly dependent on bulk IL concentration.

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