scholarly journals An Investigation on the Application of Pulsed Electrodialysis Reversal in Whey Desalination

2019 ◽  
Vol 20 (8) ◽  
pp. 1918 ◽  
Author(s):  
Arthur Merkel ◽  
Amir M. Ashrafi
Keyword(s):  
Contact Angle ◽  
Anion Exchange ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Anion Exchange Membranes ◽  
Sem Images ◽  
Short Pulses ◽  
Back Transfer

Electrodialysis (ED) is frequently used in the desalination of whey. However, the fouling onto the membrane surface decreases the electrodialysis efficiency. Pulsed Electrodialysis Reversal (PER), in which short pulses of reverse polarity are applied, is expected to decrease the fouling onto membrane surface during ED. Three (PER) regimes were applied in the desalination of acid whey (pH ≤ 5) to study their effects on the membrane fouling and the ED efficiency. The PER regimes were compared to the conventional ED as the control. For each regime, two consecutive runs were performed without any cleaning step in-between to intensify the fouling. After the second run, the membranes were subjected to the Scanning electron microscope (SEM) imaging and contact angle measurement to investigate the fouling on the membrane surface in different regimes. The ED parameters in the case of conventional ED were almost the same in the first and the second runs. However, the parameters related to the ED efficiency including ED capacity, ash transfer, and ED time, were deteriorated when the PER regimes were applied. The contact angle values indicated that the fouling on the diluate side of anion exchange membranes was more intensified in conventional ED compared to the PER regimes. The SEM images also showed that the fouling on the diluate side of both cation and anion exchange membranes under PER regimes was reduced in respect to the conventional ED. However, the back transfer to the diluate compartment when the reverse pulse was applied is dominant and lowers the ED efficiency slightly when the PER is applied.

scholarly journals Influential Mechanism of Natural Organic Matters with Calcium Ion on the Anion Exchange Membrane Fouling Behavior via xDLVO Theory

Membranes ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 968
Author(s):  
Zhun Ma ◽  
Lu Zhang ◽  
Ying Liu ◽  
Xiaosheng Ji ◽  
Yuting Xu ◽  
...  
Keyword(s):  
Organic Matter ◽  
Interaction Energy ◽  
Anion Exchange ◽  
Natural Organic Matter ◽  
Calcium Ions ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Anion Exchange Membrane ◽  
Anion Exchange Membranes ◽  
Exchange Membrane

The fouling mechanism of the anion exchange membrane (AEM) induced by natural organic matter (NOM) in the absence and presence of calcium ions was systematically investigated via the extended Derjaguin–Landau–Verwey–Overbeek (xDLVO) approach. Sodium alginate (SA), humic acid (HA), and bovine serum albumin (BSA) were utilized as model NOM fractions. The results indicated that the presence of calcium ions tremendously aggravated the NOM fouling on the anion exchange membrane because of Ca-NOM complex formation. Furthermore, analysis of the interaction energy between the membrane surface and foulants via xDLVO revealed that short-range acid–base (AB) interaction energy played a significant role in the compositions of interaction energy during the electrodialysis (ED) process. The influence of NOM fractions in the presence of calcium ions on membrane fouling followed the order: SA > BSA > HA. This study demonstrated that the interaction energy was a dominating indicator for evaluating the tendency of anion exchange membranes fouling by natural organic matter.

Oxygen Cold Plasma Treatment to Improve Hydrophilicity of HDPE Pellets

2013 ◽  
Vol 747 ◽  
pp. 210-213 ◽  
Author(s):  
Mintra Meemusaw ◽  
Rathanawan Magaraphan
Keyword(s):  
Contact Angle ◽  
Plasma Treatment ◽  
Cold Plasma ◽  
Treatment Time ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Polar Component ◽  
Sem Images ◽  
Cross Sectional ◽  
Polar Polymer

We demonstrated the environmentally friendly method, Cold Plasma treatment with oxygen plasma gas, in order to introduce the polar groups into non-polar polymer. HDPE pellets were treated with cold plasma under the mixture of plasma gas and air at atmospheric pressure. After that, the treated samples were immediately subjected into the twin-screw extruder. Plasma treatment time, 30 seconds, 1 and 2 minutes, was studied. From the contact angle measurement, all treated samples showed lower contact angle value than the neat HDPE from 96.83° to 80.84° - 84.53° suggesting that the hydrophilicity of all treated samples were improved. The polar part of surface free energy (γsp) of all treated samples increased from the neat HDPE from almost zero to 13.34-21.88 mN/m. ATR-FTIR results confirmed the increasing of γsp value. It was due to the new oxygenated functional groups which were introduced into the non-polar polymer. Lastly, from SEM images, the roughness of cross-sectional area increased after plasma treatment which attributed to the incompatible between the polar component and the non-polar component.

Fabrication of Super-Hydrophobic Membrane with Hydrophilic Polyethersulphone

2011 ◽  
Vol 396-398 ◽  
pp. 361-366
Author(s):  
Guang Fen Li ◽  
Xu Dong Sun ◽  
Yu Zhong Zhang
Keyword(s):  
Contact Angle ◽  
Sol Gel ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Hydrophobic Membrane ◽  
Sem Images ◽  
Simple Method ◽  
Membrane Surfaces ◽  
Sol Gel Process ◽  
Experimental Parameters

Here a simple method was developed to fabricate super-hydrophobic membrane with hydrophilic Polyethersulphone (PES) via a sol-gel process. The influences of experimental parameters i.e. the precursor treated time, the baking temperature of the membrane, and the fluorinated time on the hydrophobicity of the membranes were extensively investigated. The correspondent hydrophobicity was crosschecked by the contact angle measurement. For the optimum condition, the contact angle of the resulted super-hydrophobic membrane can be increased to 156°. The FTIR analysis confirmed that the membrane surfaces were covered by hydrophobic functional groups, which resulted in both higher surface roughness and higher heterogeneity, and therefore higher hydrophobicity. The micro/nano-meter crater-like protrusions on the membrane surfaces were observed from the images obtained from both AFM and SEM measurements. Moreover, the spongy holes and the finger-like holes were observed in cortex and intermediate layer respectively, from the cross-section of the SEM images.

scholarly journals Superhydrophobic functionalized cellulosic paper by copper hydroxide nanorods for oils purification

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ahmed S. Belal ◽  
Jehan El Nady ◽  
Azza Shokry ◽  
Shaker Ebrahim ◽  
Moataz Soliman ◽  
...  
Keyword(s):  
Contact Angle ◽  
Filter Paper ◽  
Separation Efficiency ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Absorption Capacity ◽  
Morphological Properties ◽  
Copper Hydroxide ◽  
Immersion Method ◽  
Water Contact

AbstractOily water contamination has been sighted as one of the most global environmental pollution. Herein, copper hydroxide nanorods layer was constructed onto cellulosic filter paper surface cured with polydopamine, Ag nanoparticles, and Cu NPs through immersion method. This work has been aimed to produce a superhydrophobic and superoleophilic cellulosic filter paper. The structure, crystalline, and morphological properties of these modified cellulosic filter paper were investigated. Scanning electron microscope images confirmed that the modified surface was rougher compared with the pristine surface. The contact angle measurement confirmed the hydrophobic nature of these modified surfaces with a water contact angle of 169.7°. The absorption capacity was 8.2 g/g for diesel oil and the separation efficiency was higher than 99%. It was noted that the flux in the case of low viscosity solvent as n-hexane was 9663.5 Lm−2 h−1, while for the viscous oil as diesel was 1452.7 Lm−2 h−1.

Preparation and the Blood Compatibility of Titanium Oxide Nanorod Arrays

2011 ◽  
Vol 306-307 ◽  
pp. 25-30 ◽  
Author(s):  
Ping Luo ◽  
Zhan Yun Huang ◽  
Di Hu Chen
Keyword(s):  
Contact Angle ◽  
Surface Morphology ◽  
Titanium Oxide ◽  
Tin Oxide ◽  
Growth Parameters ◽  
Blood Compatibility ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Nanorod Arrays ◽  
Wetting Properties

In this work, titanium oxide nanorod arrays were fabricated by using the hydrothermal method on fluorine-doped tin oxide (FTO) coated glass. The diameter of the nanorods could be controlled from 150 nm to 30 nm by changing the growth parameters. The surface morphology and the structure of the samples were characterized by SEM and XRD. The wetting properties were identified by contact angle measurement. Platelet attachment was investigated to evaluate the blood compatibility of the samples with different nanoscale topographies. Results show that the nanotopographical surfaces perform outstanding blood compatibility, and the adhering platelet decreased with the increasing diameter of the nanorods.

Measurement of wheel-terrain contact angle for WMRs on rough terrain using laser scanning sensor

2017 ◽  
Vol 44 (6) ◽  
pp. 798-807 ◽  
Author(s):  
He Xu ◽  
Yan Xu ◽  
Peiyuan Wang ◽  
Hongpeng Yu ◽  
Ozoemena Anthony Ani ◽  
...  
Keyword(s):  
Contact Angle ◽  
Laser Scanning ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Rough Terrain ◽  
Wheeled Mobile Robots ◽  
Wheel Slip ◽  
Content Type ◽  
Terrain Model ◽  
Measurement Approach

Purpose The purpose of this paper is to explore a novel measurement approach for wheel-terrain contact angle using laser scanning sensors based on near-terrain perception. Laser scanning sensors have rarely been applied to the measurement of wheel-terrain contact angle for wheeled mobile robots (WMRs) in previous studies; however, it is an effective way to measure wheel-terrain contact angle directly with the advantages of simple, fast and high accuracy. Design/methodology/approach First, kinematics model for a WMR moving on rough terrain was developed, taking into consideration wheel slip and wheel-terrain contact angle. Second, the measurement principles of wheel-terrain contact angle using laser scanning sensors was presented, including “rigid wheel - rigid terrain” model and “rigid wheel - deformable terrain” model. Findings In the proposed approach, the measurement of wheel-terrain contact angle using laser scanning sensors was successfully demonstrated. The rationality of the approach was verified by experiments on rigid and sandy terrains with satisfactory results. Originality/value This paper proposes a novel, fast and effective wheel-terrain contact angle measurement approach for WMRs moving on both rigid and deformable terrains, using laser scanning sensors.

Contact Angle of Nepenthes alata Slippery Zone: Results from Measurement and Model Analysis

2021 ◽  
pp. 1-7
Author(s):  
Lixin Wang ◽  
Pan Pan ◽  
Shixing Yan ◽  
Shiyun Dong
Keyword(s):  
Contact Angle ◽  
Hierarchical Structures ◽  
Model Analysis ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Structure Characteristic ◽  
Baxter Equation ◽  
Measured Contact Angle ◽  
The Relationship ◽  
Contact Angle Analysis

The slippery zone of Nepenthes alata depends on its highly evolved morphology and structure to show remarkable superhydrophobicity, which has gradually become a biomimetic prototype for developing superhydrophobic materials. However, the mechanism governing this phenomenon has not been fully revealed through model analysis. In this paper, the superhydrophobicity of slippery zone is studied by contact angle measurement, morphology/structure examination and model analysis. The slippery zone causes ultrapure water droplet to produce a considerably high contact angle (155.11–158.30°), and has a micro-nano scale hierarchical structures consisting of lunate cells and wax coverings. According to the Cassie-Baxter equation and a self-defined infiltration coefficient, a model was established to analyze the effect of structure characteristic on the contact angle. Analysis result showed that the calculated contact angle (154.67–159.49°) was highly consistent with the measured contact angle, indicating that the established model can quantitatively characterize the relationship between the contact angle and the structure characteristic. Our study provides some evidences to further reveal the superhydrophobic mechanism of Nepenthes alata slippery zone, as well as inspires the biomimetic development of superhydrophobic surfaces.

Contact angle measurement on rough surfaces

2004 ◽  
Vol 274 (2) ◽  
pp. 637-644 ◽  
Author(s):  
Tammar S. Meiron ◽  
Abraham Marmur ◽  
I.Sam Saguy
Keyword(s):  
Contact Angle ◽  
Rough Surfaces ◽  
Contact Angle Measurement ◽  
Angle Measurement

Curing Time and Water Repellent Properties of Dammar-Titanium Dioxide Thin Film

2015 ◽  
Vol 1112 ◽  
pp. 359-362
Author(s):  
Aisyah Nor Hasnan ◽  
Azizah Hanom Ahmad
Keyword(s):  
Contact Angle ◽  
Titanium Dioxide ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Water Repellent ◽  
Coating System ◽  
Curing Time ◽  
Coating Surface ◽  
Natural Resin ◽  
Before And After

Dammar plant resin is a local natural resin that can be bled from Dipterocaupacea sp of tree. It can be found abundantly in Malaysia’s tropical forest especially in Sarawak. Dammar and Titanium Dioxide was mixed in a various wt% to produce Dammar-modified Titanium Dioxide coating system. The modified coating systems were then spin-coated onto Aluminium Q-panel as the substrate. Coated Q-panels were left to cure at room temperature. The curing time was evaluated using dust free stage. The addition of Titanium Dioxide into the coating system fastens the curing time taken for the coated Q-panel to be cure. It only took about 11-12 minutes to dry compared to the coating system before the addition of Titanium Dioxide where a quite long duration required, 32 minutes. Contact angle measurement was also carried out in order to determine the wettability of the coating system. The surface coated with dammar-modified titanium dioxide found to be hydrophobic where a quite large contact angle obtained for the sample with 3 wt% of Titanium Dioxide (PDT3). The water droplets actually rest on the coating surface without wetting the surface. Water absorption test was done to strengthen the contact angle results where coated substrate was soaked into distilled water for 24 hours and being weighed before and after soaking. The difference of before and after soaking weigh showed that the coating surface does not absorb that much water where only approximately 0.02% of water being absorbed by the coating system for 3 wt%. It proved that the coating systems applied are hydrophobic.

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