Preparation and Surface Modification of Poly(acrylonitrile-co-acrylic acid) Electrospun Nanofibrous Membranes

2008 ◽  
Vol 61 (6) ◽  
pp. 446 ◽  
Author(s):  
Ai-Fu Che ◽  
Xiao-Jun Huang ◽  
Zhen-Gang Wang ◽  
Zhi-Kang Xu

Poly(acrylonitrile-co-acrylic acid) (PANCAA) was synthesized and fabricated into nanofibrous membranes by an electrospinning technique. Scanning electron microscopy revealed that membranes composed of uniformly thin and smooth nanofibres were obtained under optimized processing parameters. Surface modification with chitosan on these nanofibrous membranes was accomplished by a coupling reaction between the carboxylic groups of PANCAA and the primary amino groups of chitosan. Fluorescent labelling, weight measurement, FT-IR/ATR spectroscopy, and X-ray photoelectron spectroscopy (XPS) were used to confirm the modification process and determine the immobilization degree of chitosan. Platelet adhesion experiments were further carried out to evaluate the hemocompatibility of the studied nanofibrous membranes. Preliminary results indicated that the immobilization of chitosan on the PANCAA nanofibrous membranes was favourable for platelet adhesion.

2011 ◽  
Vol 12 (12) ◽  
pp. 4348-4356 ◽  
Author(s):  
Wei-Hsuan Kuo ◽  
Meng-Jiy Wang ◽  
Hsiu-Wen Chien ◽  
Ta-Chin Wei ◽  
Chiapyng Lee ◽  
...  

2008 ◽  
Vol 9 (12) ◽  
pp. 3397-3403 ◽  
Author(s):  
Ai-Fu Che ◽  
Zhen-Mei Liu ◽  
Xiao-Jun Huang ◽  
Zhen-Gang Wang ◽  
Zhi-Kang Xu

2009 ◽  
Vol 57 (1-4) ◽  
pp. 250-256 ◽  
Author(s):  
Xiao-Jun Huang ◽  
An-Guo Yu ◽  
Jun Jiang ◽  
Chao Pan ◽  
Jing-Wen Qian ◽  
...  

RSC Advances ◽  
2014 ◽  
Vol 4 (77) ◽  
pp. 40892-40897 ◽  
Author(s):  
Zahed Shami ◽  
Naser Sharifi-Sanjani ◽  
Bafrin Khanyghma ◽  
Sadegh Farjpour ◽  
Azam Fotouhi

Well-ordered/dispersed exfoliated clay platelets aligned along as-electrospun PAA–PEO/Na–MMT composite nanofibrous membranes were synthesized successfully for the first time.


2013 ◽  
Vol 58 (1) ◽  
pp. 95-98 ◽  
Author(s):  
M. Zielinska ◽  
J. Sieniawski

Superalloy René 77 is very wide used for turbine blades, turbine disks of aircraft engines which work up to 1050°C. These elements are generally produced by the investment casting method. Turbine blades produced by conventional precision casting methods have coarse and inhomogeneous grain structure. Such a material often does not fulfil basic requirements, which concern mechanical properties for the stuff used in aeronautical engineering. The incorporation of controlled grain size improved mechanical properties. This control of grain size in the casting operation was accomplished by the control of processing parameters such as casting temperature, mould preheating temperature, and the use of grain nucleates in the face of the mould. For nickel and cobalt based superalloys, it was found that cobalt aluminate (CoAl2O4) has the best nucleating effect. The objective of this work was to determine the influence of the inoculant’s content (cobalt aluminate) in the surface layer of the ceramic mould on the microstructure and mechanical properties at high temperature of nickel based superalloy René 77. For this purpose, the ceramic moulds were made with different concentration of cobalt aluminate in the primary slurry was from 0 to 10% mass. in zirconium flour. Stepped and cylindrical samples were casted for microstructure and mechanical examinations. The average grain size of the matrix ( phase), was determined on the stepped samples. The influence of surface modification on the grain size of up to section thickness was considered. The microstructure investigations with the use of light microscopy and scanning electron microscopy (SEM) enable to examine the influence of the surface modification on the morphology of ’ phase and carbides precipitations. Verification of the influence of CoAl2O4 on the mechanical properties of castings were investigated on the basis of results obtained form creep tests.


2021 ◽  
Author(s):  
Ahmed Esmail Shalan ◽  
M. Afifi ◽  
M.M. El-Desoky ◽  
M.k Ahmed

Cellulose acetate nanofiber membranes containing hydroxyapatite co-doped with Ag/Fe were efficaciously attained through the electrospinning technique. Different molar ratio compositions of hydroxyapatite co-doped with Ag/Fe in the structure of the...


Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1601
Author(s):  
Jorge Contreras-Martínez ◽  
Carmen García-Payo ◽  
Mohamed Khayet

As a consequence of the increase in reverse osmosis (RO) desalination plants, the number of discarded RO modules for 2020 was estimated to be 14.8 million annually. Currently, these discarded modules are disposed of in nearby landfills generating high volumes of waste. In order to extend their useful life, in this research study, we propose recycling and reusing the internal components of the discarded RO modules, membranes and spacers, in membrane engineering for membrane distillation (MD) technology. After passive cleaning with a sodium hypochlorite aqueous solution, these recycled components were reused as support for polyvinylidene fluoride nanofibrous membranes prepared by electrospinning technique. The prepared membranes were characterized by different techniques and, finally, tested in desalination of high saline solutions (brines) by direct contact membrane distillation (DCMD). The effect of the electrospinning time, which is the same as the thickness of the nanofibrous layer, was studied in order to optimize the permeate flux together with the salt rejection factor and to obtain robust membranes with stable DCMD desalination performance. When the recycled RO membrane or the permeate spacer were used as supports with 60 min electrospinning time, good permeate fluxes were achieved, 43.2 and 18.1 kg m−2 h−1, respectively; with very high salt rejection factors, greater than 99.99%. These results are reasonably competitive compared to other supported and unsupported MD nanofibrous membranes. In contrast, when using the feed spacer as support, inhomogeneous structures were observed on the electrospun nanofibrous layer due to the special characteristics of this spacer resulting in low salt rejection factors and mechanical properties of the electrospun nanofibrous membrane.


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