scholarly journals Tuning the Electrochemical Properties of Novel Asymmetric Integral Sulfonated Polysulfone Cation Exchange Membranes

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 265
Author(s):  
Ahmet Halil Avci ◽  
Cédric Van Goethem ◽  
Timon Rijnaarts ◽  
Sergio Santoro ◽  
Marco Aquino ◽  
...  

In this study, novel asymmetric integral cation exchange membranes were prepared by the wet phase inversion of sulfonated polysulfone (SPSf) solutions. SPSf with different degrees of sulfonation (DS) was synthesized by variation in the amount of chlorosulfonic acid utilized as a sulfonating agent. The characterization of SPSf samples was performed using FTIR and 1H-NMR techniques. SPSf with a DS of 0.31 (0.67 meq/g corresponding ion exchange capacity) was chosen to prepare the membranes, as polymers with a higher DS resulted in poor mechanical properties and excessive swelling in water. By a systematic study, the opportunity to tune the properties of SPSf membranes by acting on the composition of the polymeric solution was demonstrated. The effect of two different phase inversion parameters, solvent type and co-solvent ratio, were investigated by morphological and electrochemical characterization. The best properties (permselectivity of 0.86 and electrical resistance of 6.3 Ω∙cm2) were obtained for the membrane prepared with 2-propanol (IPA):1-Methyl-2-pyrrolidinone (NMP) in a 20:80 ratio. This membrane was further characterized in different solution concentrations to estimate its performance in a Reverse Electrodialysis (RED) operation. Although the estimated generated power was less than that of the commercial CMX (Neosepta) membrane, used as a benchmark, the tailor-made membrane can be considered as a cost-effective alternative, as one of the main limitations to the commercialization of RED is the high membrane price.

2006 ◽  
Vol 45 ◽  
pp. 209-217
Author(s):  
Tatsuya Kodama ◽  
Nobuyuki Gokon ◽  
Sridhar Komarneni

This paper reviews synthesis, characterization and cation exchange properties of a novel swelleing mica "Na-4-mica" and their synthetic analogues with a high layer charge denisty. Na-4-mica (Na4Mg6Al4Si4O20F4) of a synthetic brittle mica has a very high Al(III) content and but exhibits unusual swelling behavior and selective cation exchange properties potentially useful in hazardous cation separations from solutions. Although normal brittle micas do not swell in water at all, this synthetic mica can readily become hydrated upon contact with water or even in moist air. This mica has a theoretical cation-exchange capacity of 468 milli-equivalents per 100 g on an anhydrous basis. The present authors found a simple and cost-effective preparation process of micro- or nano-crystallites of this mica from naturally occurring clay kaolinite. The fine mica is a selective exchanger for Sr, Ba, Ra, Pb, Cu, or Zn. The modified micas, such as "Na-3-mica" and "Na-2-mica" were also synthesized by the similar syntehtic processes. Na-3-mica improved the cation exchange kinetics and capacity for Sr. These micas also exhibited extremely low cation leachability once dehydrated at room temperature or moderate temperatures, and, hence, are expected to be useful for radioactive strontium or radium removal followed by its immobilization for safe disposal.


2020 ◽  
pp. 1192-1198
Author(s):  
M.S. Mohammad ◽  
Tibebe Tesfaye ◽  
Kim Ki-Seong

Ultrasonic thickness gauges are easy to operate and reliable, and can be used to measure a wide range of thicknesses and inspect all engineering materials. Supplementing the simple ultrasonic thickness gauges that present results in either a digital readout or as an A-scan with systems that enable correlating the measured values to their positions on the inspected surface to produce a two-dimensional (2D) thickness representation can extend their benefits and provide a cost-effective alternative to expensive advanced C-scan machines. In previous work, the authors introduced a system for the positioning and mapping of the values measured by the ultrasonic thickness gauges and flaw detectors (Tesfaye et al. 2019). The system is an alternative to the systems that use mechanical scanners, encoders, and sophisticated UT machines. It used a camera to record the probe’s movement and a projected laser grid obtained by a laser pattern generator to locate the probe on the inspected surface. In this paper, a novel system is proposed to be applied to flat surfaces, in addition to overcoming the other limitations posed due to the use of the laser projection. The proposed system uses two video cameras, one to monitor the probe’s movement on the inspected surface and the other to capture the corresponding digital readout of the thickness gauge. The acquired images of the probe’s position and thickness gauge readout are processed to plot the measured data in a 2D color-coded map. The system is meant to be simpler and more effective than the previous development.


2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Mardi Wibowo

Since year 1977 until 2005, PT. ANTAM has been exploited nickel ore resources at Gebe Island – Center ofHalmahera District – North Maluku Province. Mining activity, beside give economically advantages also causedegradation of environment quality espicially land quality. Therefore, it need evaluation activity for change ofland quality at Gebe Island after mining activity.From chemical rehabilitation aspect, post mining land and rehabilitation land indacate very lack and lackfertility (base saturated 45,87 – 99,6%; cation exchange capacity 9,43 – 12,43%; Organic Carbon 1,12 –2,31%). From availability of nutrirnt element aspect, post mining land and rehabilitation land indicate verylack and lack fertility (nitrogen 0,1 – 1,19%). Base on that data, it can be concluded that land reclamationactivity not yet achieve standart condition of chemical land.Key words : land quality, post mining lan


Alloy Digest ◽  
1980 ◽  
Vol 29 (11) ◽  

Abstract JS777 is a high-alloy, fully austenitic stainless steel developed for applications where corrosive conditions are too severe for the standard grades of stainless steel. It also provides a cost-effective alternative to more expensive nickel-base and titanium-base alloys. It has relatively high resistance to stress-corrosion cracking and to intergranular corrosion. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SS-377. Producer or source: Jessop Steel Company.


Alloy Digest ◽  
2009 ◽  
Vol 58 (11) ◽  

Abstract Ancorsteel 4300 alloy ferrous powder simulates wrought steel compositions and is a cost-effective alternative to alloys requiring secondary processing. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as fracture toughness. It also includes information on heat treating and powder metal forms. Filing Code: SA-611. Producer or source: Hoeganaes Corporation.


Author(s):  
Geraldo R. Zuba Junio ◽  
Regynaldo A. Sampaio ◽  
Altina L. Nascimento ◽  
Luiz A. Fernandes ◽  
Natália N. de Lima ◽  
...  

ABSTRACTThis study aimed to evaluate the chemical attributes of an Inceptisol cultivated with castor bean (Ricinus communis L.), variety ‘BRS Energia’, fertilized with sewage sludge compost and calcium (Ca) and magnesium (Mg) silicate. The experiment was conducted at the ICA/UFMG, in a randomized block design, using a 2 x 4 factorial scheme with three replicates, and the treatments consisted of two doses of Ca-Mg silicate (0 and 1 t ha-1) and four doses of sewage sludge compost (0, 23.81, 47.62 and 71.43 t ha-1, on dry basis). Soil organic matter (OM), pH, sum of bases (SB), effective cation exchange capacity (CEC(t)), total cation exchange capacity (CEC(T)), base saturation (V%) and potential acidity (H + Al) were evaluated. There were no significant interactions between doses of sewage sludge compost and doses of Ca-Mg silicate on soil attributes, and no effect of silicate fertilization on these attributes. However, fertilization with sewage sludge compost promoted reduction in pH and increase in H + Al, OM and CEC. The dose of 71.43 t ha-1 of sewage sludge compost promoted the best soil chemical conditions.


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