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

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.

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.


2017 ◽  
Vol 89 (3) ◽  
pp. 401-410 ◽  
Author(s):  
Yongqiang Li ◽  
Chao Zou ◽  
Jianzhong Shao ◽  
Ya’nan Li

Cotton fabric is commonly used in daily life, but it is easily wetted and contaminated by liquid. Herein, we present a simple and environmentally friendly plasma technology for hydrophobic modification of cotton fabric. In order to endow superhydrophobicity to cotton fabric, helium plasma inducing graft polymerization of 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane (D4Vi) was utilized to wrap SiO2 particles on cotton fabrics. Cotton fabrics were successively dipped in silica sol and D4Vi, then treated by plasma. Cotton fabrics before and after modification were characterized by using field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and water contact angle measurement. The experimental results showed that the cotton-SiO2-D4Vi consisted of nanoscale SiO2 protrusions and low-surface-energy film polymerized by D4Vi. In addition, the one wrapped SiO2 of 161 nm presented excellent hydrophobicity, washing durability, and repellency toward different types of liquids with a water contact angle of 152°.


1993 ◽  
Vol 20 (4) ◽  
pp. 297-305 ◽  
Author(s):  
C. O'Kane ◽  
R. G. Oliver ◽  
R. E. Blunden

Surface characteristics that are considered important for bacterial attachment to thirteen orthodontic bonding composite cements and one glass ionomer cement were examined in vitro before and after toothbrush abrasion. The surface roughness and contact angle measurements were found to be statistically significantly different between the materials, both before and after brushing, and there were also statistically significant changes within materials after brushing. There were low correlation coefficients between surface roughness and contact angle for both pre-and post-brushed materials.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ahmed S. Belal ◽  
Jehan El Nady ◽  
Azza Shokry ◽  
Shaker Ebrahim ◽  
Moataz Soliman ◽  
...  

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.


2011 ◽  
Vol 306-307 ◽  
pp. 25-30 ◽  
Author(s):  
Ping Luo ◽  
Zhan Yun Huang ◽  
Di Hu Chen

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.


Author(s):  
He Xu ◽  
Yan Xu ◽  
Peiyuan Wang ◽  
Hongpeng Yu ◽  
Ozoemena Anthony Ani ◽  
...  

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.


Author(s):  
Lixin Wang ◽  
Pan Pan ◽  
Shixing Yan ◽  
Shiyun Dong

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.


2004 ◽  
Vol 274 (2) ◽  
pp. 637-644 ◽  
Author(s):  
Tammar S. Meiron ◽  
Abraham Marmur ◽  
I.Sam Saguy

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