scholarly journals Effect of Ionic Radius in Metal Nitrate on Pore Generation of Cellulose Acetate in Polymer Nanocomposite

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 981
Author(s):  
Woong Gi Lee ◽  
Younghyun Cho ◽  
Sang Wook Kang
Keyword(s):  
Cellulose Acetate ◽  
Ionic Radius ◽  
Water Pressure ◽  
Water Flux ◽  
Atomic Radius ◽  
Ionic Species ◽  
Metal Nitrate ◽  
Hydraulic Pressure ◽  
Physical Force ◽  
Nitrate Salts

To prepare a porous cellulose acetate (CA) for application as a battery separator, Cd(NO3)2·4H2O was utilized with water-pressure as an external physical force. When the CA was complexed with Cd(NO3)2·4H2O and exposed to external water-pressure, the water-flux through the CA was observed, indicating the generation of pores in the polymer. Furthermore, as the hydraulic pressure increased, the water-flux increased proportionally, indicating the possibility of control for the porosity and pore size. Surprisingly, the value above 250 LMH (L/m2h) observed at the ratio of 1:0.35 (mole ratio of CA: Cd(NO3)2·4H2O) was of higher flux than those of CA/other metal nitrate salts (Ni(NO3)2 and Mg(NO3)2) complexes. The higher value indicated that the larger and abundant pores were generated in the cellulose acetate at the same water-pressure. Thus, it could be thought that the Cd(NO3)2·4H2O salt played a role as a stronger plasticizer than the other metal nitrate salts such as Ni(NO3)2 and Mg(NO3)2. These results were attributable to the fact that the atomic radius and ionic radius of the Cd were largest among the three elements, resulting in the relatively larger Cd of the Cd(NO3)2 that could easily be dissociated into cations and NO3− ions. As a result, the free NO3− ions could be readily hydrated with water molecules, causing the plasticization effect on the chains of cellulose acetate. The coordinative interactions between the CA and Cd(NO3)2·4H2O were investigated by IR spectroscopy. The change of ionic species in Cd(NO3)2·4H2O was analyzed by Raman spectroscopy.

Effect of the structure of cellulose acetate membranes on their permeability, electrical conductivity and rejection

1990 ◽  
Vol 55 (12) ◽  
pp. 2933-2939 ◽  
Author(s):  
Hans-Hartmut Schwarz ◽  
Vlastimil Kůdela ◽  
Klaus Richau
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Cellulose Acetate ◽  
Reverse Osmosis ◽  
Water Flux ◽  
Cellulose Acetate Membrane ◽  
Structure Parameters ◽  
Dc Electrical Conductivity ◽  
Cellulose Acetate Membranes

Ultrafiltration cellulose acetate membrane can be transformed by annealing into reverse osmosis membranes (RO type). Annealing brings about changes in structural properties of the membranes, accompanied by changes in their permeability behaviour and electrical properties. Correlations between structure parameters and electrochemical properties are shown for the temperature range 20-90 °C. Relations have been derived which explain the role played by the dc electrical conductivity in the characterization of rejection ability of the membranes in the reverse osmosis, i.e. rRO = (1 + exp (A-B))-1, where exp A and exp B are statistically significant correlation functions of electrical conductivity and salt permeation, or of electrical conductivity and water flux through the membrane, respectively.

scholarly journals Numerical Analysis to Assess the Vertical Drainage Within Flexible Pavement.

2018 ◽  
Vol 7 (4.20) ◽  
pp. 95
Author(s):  
Aqeel Al-Adili ◽  
Rasha H. Abdul-Amir ◽  
Osamah Hassan Chfat
Keyword(s):  
Cross Section ◽  
Rainfall Intensity ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Water Flux ◽  
Flexible Pavement ◽  
Laboratory Model ◽  
Typical Structure ◽  
Rainy Period ◽  
Vertical Drainage

In this research the work methodology include the software program SEEP/W routine of the GEOSLOPE 2012; which was used to simulate and analyze the vertical drainage of the pavement cross section using steady-state and transient analysis. A laboratory model consisting of typical structure layers of flexible pavement was considered in this research with a 2% slope with the influence of three different rain intensities (30mm/min, 60mm/min and 90mm/min); in which each one has a duration differs from the other. The results indicated that the value of the pore-water pressure in the surface layer resulting from 90 mm/min rainfall intensity is 83.65% greater than the pressure generated by the 60mm/min intensity of rain and 91.076% greater than the pressure produced from 30mm/min intensity. The average of accumulation water produced by the 30mm/min rainfall intensity in the pavement structure is 44.73 % greater than the average of accumulation of water from the 60mm/min intensity and 77.85% higher than the 90mm/min intensity of rain. The water flux through the pavement cross section during the rainy period of 30 mm/min was 8.42% higher than the water flux of 60 mm/min and 49.82% of the water flux of 90 mm/min intensity of rain.  

scholarly journals Water Transport in Unsaturated Cracked Concrete under Pressure

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Yuanzhu Zhang ◽  
Siming Zhang ◽  
Gang Wei ◽  
Xinjiang Wei ◽  
Liqiao Jin ◽  
...  
Keyword(s):  
Water Transport ◽  
Driving Force ◽  
Crack Width ◽  
Water Pressure ◽  
Theoretical Models ◽  
Double Porosity ◽  
Hydraulic Pressure ◽  
Pressure Potential ◽  
Cracked Concrete ◽  
Concrete Permeability

In order to analyze the process of hydraulic water infiltrating cracked concrete of underwater tunnels, the equation of water transport in unsaturated cracked concrete under pressure was proposed according to the double-porosity medium model. Penetration tests on prefabricated cracked concrete blocks were conducted, and then the influence of hydraulic pressure, initial saturation, and crack width on water transport was studied. The results show that the larger the water pressure, the lower the initial saturation, and the wider the crack width, then the greater the penetration depth, which can be reasonably explained according to water motion theoretical models in this study. Moreover, the TOUGH2 software was used to simulate the change and distribution of saturation, driving potential, and water velocity of unsaturated cracked concrete, which further proved the experimental results and theoretical analysis. It reflects that both pressure potential and matric potential are the driving force of water transport in underwater cracked concrete, and the driving force will be converted with the change of concrete saturation. In addition, crack width is positively correlated with concrete permeability.

scholarly journals INCORPORATION OF IMPRINTED-ZEOLITE TO POLYETHERSULFONE/CELLULOSE ACETATE MEMBRANE FOR CREATININE REMOVAL IN HEMODIALYSIS TREATMENT

2019 ◽  
Vol 81 (3) ◽  
Author(s):  
Yanuardi Raharjo ◽  
Mochamad Zakki Fahmi ◽  
Siti Wafiroh ◽  
Alfa Akustia Widati ◽  
Eviomitta Rizki Amanda ◽  
...  
Keyword(s):  
Cellulose Acetate ◽  
Pure Water ◽  
Water Flux ◽  
Hollow Fibre ◽  
Mixed Matrix Membranes ◽  
Mixed Matrix Membrane ◽  
Cellulose Acetate Membrane ◽  
Zeolite A ◽  
Mixed Matrix ◽  
Water Contact

Polyethersulfon (PES) membrane has been widely used in the biomedical field especially in hemodialysis application. Many modifications of membranes have been applied into hemodialysis such as diffusion, adsorption, and mixed-matrix membrane. The main problem of those membranes is less selectivity to attract the uremic toxins. In this study, we report the modification of PES mixed with cellulose acetate (PES/CA) membrane as mixed-matrix membrane (MMM) using imprinted-zeolite (PES/CA/IZC) in order to increase the selectivity for targeted analyte. The hollow fibre membranes (HFM) were fabricated by dry-wet spinning technique. The successful zeolite A synthesised and was characterised by x-ray diffraction (XRD). The mixed-matrix membranes were characterised in terms of morphology using scanning electron microscopy (SEM), water contact angle (WCA), pure water flux (PWF), clearance of creatinine (CC), and BSA adsorption. In accordance with the results of characterisation, the synthesis of zeolite A, and imprinted-zeolite creatinine was successfully fabricated. The SEM results showed that the PES/CA/IZC membrane has uniform pores and fingerlike structure. The same result was obtained for PES/CA membrane, but not for PES/CA/ZA membrane. The WCA of the PES/CA; PES/CA/ZA; and PES/CA/IZC were 85.63; 84.98; and 77.53 (o), respectively. While the PWF were 22.84; 27.57, and 40.52 (Lm-2h-1), respectively. The addition of imprinted-zeolite into the membrane improved creatinine removal up to 74.99%. It showed that PES/CA/IZC has succeeded in increasing the selectivity of membranes to attract the creatinine as target analyte. Compared to the PES/CA, the creatinine clearance of membranes improved and increased up to 5.2%. For protein rejection, the PES/CA/IZC rejected 79.05% of bovine serum albumin (BSA). Based on these results, it can be concluded that PES/CA/IZC can be considered as hemodialysis membranes.

scholarly journals Liquid Crystalline Mesophases of Pluronics (L64, P65, and P123) and Transition Metal Nitrate Salts ([M(H2O)6](NO3)2)

Langmuir ◽  
2005 ◽  
Vol 21 (9) ◽  
pp. 4156-4162 ◽  
Author(s):  
A. Faik Demirörs ◽  
Bekir E. Eser ◽  
Ömer Dag
Keyword(s):  
Transition Metal ◽  
Liquid Crystalline ◽  
Metal Nitrate ◽  
Nitrate Salts

Evaluating the Potential for Damaging Hydraulic Pressure in the Concrete Tie Rail Seat

2010 ◽  
Author(s):  
John C. Zeman ◽  
J. Riley Edwards ◽  
David A. Lange ◽  
Christopher P. L. Barkan
Keyword(s):  
Surface Water ◽  
Effective Stress ◽  
Water Pressure ◽  
Hydraulic Pressure ◽  
Vertical Load ◽  
Critical Problem ◽  
Surface Geometry ◽  
State Of Stress ◽  
Pore Water Pressures ◽  
Prestressed Beam

Rail seat deterioration (RSD) is the most critical problem with concrete tie performance on North American freight railroads. Currently, the problem is not sufficiently understood to allow for effective solutions. RSD is considered to have up to five potential mechanisms, and this paper investigates one of them: hydraulic pressure cracking. A model of the effective stress in a concrete tie rail seat — considering the contributions of a uniform vertical load, a uniform lateral load, a prestressed beam on an elastic foundation, and pore pressure to the state of stress — was created to determine what surface water pressures at the rail seat could lead to damaging pore water pressures in the concrete. A laboratory test setup and procedure were devised to measure the surface water pressure in a laboratory rail seat using tie pads of differing material composition and geometry. Results show that the magnitude of the pressure generated and the rate of pressure dissipation with many load cycles depends on the pad material and surface geometry. Comparing the effective stress model and the measured surface pressures, hydraulic pressure cracking appears to be a feasible mechanism for RSD given the correct combination of dynamic rail seat loads, sufficient moisture, and a tie pad surface that develops high pressure.

Correlation between the pore resistance and water flux of the cellulose acetate membrane

2017 ◽  
Vol 3 (6) ◽  
pp. 1037-1041 ◽  
Author(s):  
Cheng Yin ◽  
Shuai Wang ◽  
Yongjing Zhang ◽  
Zhe Chen ◽  
Zhidong Lin ◽  
...  
Keyword(s):  
Theoretical Calculation ◽  
Cellulose Acetate ◽  
Inverse Relationship ◽  
Water Flux ◽  
Cellulose Acetate Membrane

An inverse relationship between the pore resistance and water flux was found by theoretical calculation and confirmed by the corresponding experiment.

Thermodynamic Modeling of Apparent Molal Volumes of Metal Nitrate Salts with Pitzer Model

2015 ◽  
Vol 60 (3) ◽  
pp. 856-859 ◽  
Author(s):  
Mouad Arrad ◽  
Mohammed Kaddami ◽  
Hannu Sippola ◽  
Pekka Taskinen
Keyword(s):  
Thermodynamic Modeling ◽  
Pitzer Model ◽  
Metal Nitrate ◽  
Apparent Molal Volumes ◽  
Nitrate Salts ◽  
Molal Volumes
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