Hydrophobisation of mechanical pulp fibres with sodium dodecyl sulphate functionalised layered double hydroxide particles

Holzforschung ◽  
2012 ◽  
Vol 66 (4) ◽  
Author(s):  
Carl Lange ◽  
Tom Lundin ◽  
Pedro Fardim

Abstract Hydrogen peroxide bleached spruce (Picea abies L.) made of thermo mechanical pulp (BTMP) fibres were modified with layered double hydroxides (LDH). The LDH particles were precipitated onto the BTMP fibre surfaces from aqueous solutions of urea and NaOH. The modified BTMP was further functionalised with sodium dodecyl sulphate (SDS) surfactant to produce pulp with hydrophobic character. The contact angle measurement with water on paper showed that the functionalisation with SDS was successful. The apparent contact angles varied in between the initial θ= 75° of the reference pulp up to θ= 135° of the SDS functionalised pulp. A hydrophobic surface was obtained already with 2.0% weight to weight ratio of SDS in pulp suspension. A high affinity between the LDH particles and the BTMP fibres was found as well. The investigated fibre modification route offers a new feasible tool in fibre surface treatment.

2020 ◽  
Vol 60 (1) ◽  
pp. 117
Author(s):  
Cut Aja Fauziah ◽  
Emad A. Al-Khdheeawi ◽  
Ahmed Barifcani ◽  
Stefan Iglauer

Wettability of rock–fluid systems is an important for controlling the carbon dioxide (CO2) movement and the capacities of CO2 geological trapping mechanisms. Although contact angle measurement is considered a potentially scalable parameter for evaluation of the wettability characteristics, there are still large uncertainties associated with the contact angle measurement for CO2–brine–rock systems. Thus, this study experimentally examined the wettability, before and after flooding, of two different samples of sandstone: Berea and Bandera grey sandstones. For both samples, several sets of flooding of brine (5 wt % NaCl + 1 wt % KCl in deionised water), CO2-saturated (live) brine and supercritical CO2 were performed. The contact angle measurements were conducted for the CO2–sandstone system at two different reservoir pressures (10 and 15 MPa) and at a reservoir temperature of 323 K. The results showed that both the advancing and receding contact angles of the sandstone samples after flooding were higher than that measured before flooding (i.e. after CO2 injection the sandstones became more CO2-wet). Moreover, the Bandera grey samples had higher contact angles than Berea sandstone. Thus, we conclude that CO2 flooding altered the sandstone wettability to be more CO2-wet, and Berea sandstone had a higher CO2 storage capacity than Bandera grey sandstone.


2008 ◽  
Vol 47-50 ◽  
pp. 173-176 ◽  
Author(s):  
Tao Liu ◽  
Kin Tak Lau ◽  
Shou Gang Chen ◽  
Sha Cheng ◽  
Yan Sheng Yin

A novel super-hydrophobic film was prepared by myristic acid (CH3(CH2)12COOH) chemically adsorbed onto the polyethyleneimine (PEI) coated Fe3Al-type intermetallic wafer. The film character and structure were probed with contact angle measurement, scanning electron microscopy (SEM) and atomic force microscope (AFM). The results suggest that the structure of the film is similar to lotus and the seawater contact angle is larger than 150◦. Moreover, the corrosion resistances of untreated and modified samples in seawater were investigated by electrochemical impedance spectroscopy (EIS). Experimental results show that the corrosion rate of Fe3Al-type intermetallic with super-hydrophobic surface decreases dramatically because of its special microstructure.


2017 ◽  
Vol 381 ◽  
pp. 3-7
Author(s):  
Ko Shao Chen ◽  
Shao Hsuan Tsao ◽  
Rui Wen Sung ◽  
Ying Chen Ye ◽  
Bo Han Zeng ◽  
...  

Thermoplastic urethane (TPU) nonwoven is characterized by high elasticity, tensile strength, large elongation and structural stability and widely used in biomaterial. However, the hydrophobic nature of TPU nonwoven restricts its application. To improve surface hydrophilicity and hydrophobicity, the surface modification of materials is carried out by plasma treatment or ion-beam irradiation. According to the wettability treatment experiences that substrate usually using two processing or more to get one side hydrophilic and another side hydrophobic. In this study, use of cold plasma treatment in enhancing surface wettability of TPU nonwoven was studied. The surface properties of plasma treated films are characterized by Atomic Force Microscope (AFM), water contact angle measurement, and scanning electron microscopy (SEM). This study has demonstrated that Argon plasma treatment produces hydrophobic or hydrophilic surface on the TPU nonwoven. The method is performed by first placing a hydrophobic material on one side of substrate and bring this side to face the lower electrode. By controlling the RF power of the reactor, hydrophilic or hydrophobic surface can be prepared on the other side. This technique can be applied to wound dressing.


1998 ◽  
Vol 204 (2) ◽  
pp. 342-349 ◽  
Author(s):  
Z.A. Zhou ◽  
Hish Hussein ◽  
Zhenghe Xu ◽  
Jan Czarnecki ◽  
Jacob H. Masliyah

2014 ◽  
Vol 680 ◽  
pp. 93-96
Author(s):  
Muhammad Hafiz Ab Aziz ◽  
Zaliman Sauli ◽  
Vithyacharan Retnasamy ◽  
Wan Mokhdzani Wan Norhaimi ◽  
Steven Taniselass ◽  
...  

This paper reports on the contact angle measurement analysis on a glass based surface for anodic bonding process cleaned by three distinct cleaning processes. The three types of glass based surface used were silica, pyrex, and soda lime glass. The three cleaning solutions tested in this experiment were RCA, piranha and acetone. Water Droplet Test (WDT) was done to analyze the contact angle of micro droplet on sample surface. It can be done by dropping a droplet of water in constant volume at the fixed height and angle. Only RCA process constantly decreases the contact angle value after cleaning. The compilations of data strongly proved that all samples become hydrophilic after RCA cleaning process. The solid surface is considered hydrophilic when water contact angle is smaller than 90°, and hydrophobic profile if the water contact angle is larger than 90°. Samples which undergo piranha and acetone cleaning did not prove any characteristic of hydrophilic or hydrophobic surface after cleaning.


2013 ◽  
Vol 446-447 ◽  
pp. 360-365
Author(s):  
Pusita Kuchaiyaphum ◽  
Takeshi Yamauchi ◽  
Ruangsri Watanesk ◽  
Surasak Watanesk

Eco-friendly films have been prepared using various biopolymers and their properties have been improved in order to meet the requirements for appropriate applications. However, the frequently encountered weakness of the properties of most biopolymer film is its water solubility. In this study, the polyvinyl alcohol/rice starch/silk fibroin (PVA/RS/SF) films were modified by the addition of glycerol aiming to increase the hydrophobicity of the films. Some properties of the modified films including water contact angle, degree of swelling and water solubility were compared with the unmodified PVA/RS/SF film. Results from the contact angle measurement showed that the films with glycerol could be transformed to be hydrophobic after soaking in ethanol medium. The increase in soaking time tends to increase the hydrophobicity of the films. However, at about 60 min soaking, the water contact angles on the films were quite constant with the values of about 107.9±5.2º comparing with 65.3±2.4º of the ethanol-untreated PVA/RS/SF films. In addition, the ethanol-treated glycerol-modified films also show higher degree of swelling with constant solubility and better mechanical properties.


Author(s):  
P. Zhang ◽  
W.M. Tan ◽  
B.K. Tay

Amorphous silicon-carbon films have been successfully deposited by the filtered cathodic vacuum arc techniques. One set of films was deposited from varying silicon-carbon composition in the targets and another set of films was deposited at different various substrate bias voltages from 5 at.% silicon target. The properties of the film were investigated by using atomic force microscopy (AFM), Raman spectroscopy, x-ray photoelectron spectroscopy (XPS) and contact angle measurement. The first set of the samples exhibit atomic smooth surface morphology with RMS roughness below 0.26 nm. The silicon composition in the films determined by XPS varies from 0 to 61 at.%. The Raman results show that at low silicon composition, the G peak position of C-C bond shifts to a low wavenumber, that demonstrates the silicon atom predominantly substitutes for the carbon atom. As the silicon composition increase, the G peak disappeared and a strong broad peak corresponding to the amorphous silicon carbide cluster appears around 800 cm-1. For the second set, the Raman results show the ID/IG ratio increased from 0.24 to 0.67 with using the high bias voltages during the deposition. That indicates the disorder of C-C bond within the films increased. While, both the silicon concentration in the films and contact angles remain relatively constant with the change of bias voltage.


1974 ◽  
Vol 137 (3) ◽  
pp. 575-578 ◽  
Author(s):  
Geoffrey Allen

The extent of binding of sodium dodecyl sulphate to bovine serum albumin at high binding ratios was investigated by gel filtration. The weight ratio of bound sodium dodecyl sulphate to bovine serum albumin increases with the NaCl concentration, and, except at low salt concentrations, with the concentration of sodium dodecyl sulphate. In the presence of 1.0g of sodium dodecyl sulphate/l, the binding ratio varied from 1.0 (at 0.04m-Na+) to 2.2 (at 0.44m-Na+). In the presence of 0.24m-Na+, the binding ratio increased with sodium dodecyl sulphate concentration, from 0.9 (0.2g of sodium dodecyl sulphate/l) to 2.0 (5g of sodium dodecyl sulphate/l), at 26°C, in a dilute sodium phosphate buffer. No significant dependence of the binding ratio upon temperature in the range 26–45°C was observed. These results differ from those of Reynolds & Tanford (1970a) obtained by equilibrium dialysis.


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