Top Layer Coating for Improving Superhydrophobic Property of Latex Cup

2017 ◽  
Vol 757 ◽  
pp. 52-56
Author(s):  
Sunisa Jindasuwan ◽  
Sitthisuntorn Supothina
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Field Test ◽  
Rubber Tree ◽  
Contact Angles ◽  
Economic Plant ◽  
Free Energy Surface ◽  
Immersion Method ◽  
Water Contact ◽  
Superhydrophobic Property

A latex cup is used to collect latex from a rubber tree which is an economic plant in Thailand. The fresh latex or crude rubber consists of organic compound and water which can wet and adhere to surface of the collecting cup. In this research, surface of the latex cup was treated with polymethylhydrogen siloxane-functionalized silica compound to improve hydrophobicity so that it could repel the dirt and latex, resulting in an anti-adhesion between the latex and the cup. Surface of the latex cup was etched with 10 % v/v hydrofluoric acid for 30 min before application of the siloxane coating which was performed by immersion in the solution, painting and spraying, respectively. The result revealed that the immersion method exhibited optimum property justified by high value of water contact angle, low surface free energy, surface roughness and the field test. At the optimum polymethylhydrogen siloxane : fumed silica ratio of 3 : 1 wt%, the treated sample had water contact angle of 139.24 ± 0.78 degrees and possessed surface energy of 1.07 mJ/m2. The field test conducted in the rubber field in Trang province revealed good durability of the coating. The water contact angles were 132.15 ± 2.05 and 129.20 ± 2.34 degrees after 2 weeks and 1 month, respectively, of the field service.

Fabrication and Characterization of a Superhydrophobic Low-Density Polyethylene Film

2012 ◽  
Vol 557-559 ◽  
pp. 1834-1837
Author(s):  
Jun Liang Wu ◽  
Hui Ping Zhang ◽  
Xu Nan Wang
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Energy Materials ◽  
Water Contact ◽  
Simple Method ◽  
Ldpe Film ◽  
Low Surface Energy ◽  
Special Surface ◽  
Superhydrophobic Property

A superhydrophobic LDPE film was obtained by a simple method in atmosphere without addition of low-surface-energy materials. The water contact angle of the superhydrophobic LDPE film are 155±1.9º. SEM shows that compared with common smooth LDPE film, a porous structure was obviously observed on the superhydrophobic LDPE film. Such a special surface microstructure may result in the superhydrophobic property. The effect of drying temperature and concentration on water contact angle were studied.

scholarly journals High Stability Performance of Superhydrophobic Modified Fluorinated Graphene Films on Copper Alloy Substrates

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Rafik Abbas ◽  
N. Elkhoshkhany ◽  
Ahmed Hefnawy ◽  
Shaker Ebrahim ◽  
Aya Rahal
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Sliding Angle ◽  
Water Contact ◽  
Stability Performance ◽  
Graphene Films ◽  
Superhydrophobic Property ◽  
Self Cleaning ◽  
Fluorinated Graphene ◽  
Highly Hydrophobic

A stable self-cleaning superhydrophobic modified fluorinated graphene surface with micro/nanostructure was successfully fabricated on copper substrates via drop coating process. Irregularly stacked island-like multilayered fluorinated graphene nanoflakes comprised the microstructure. The fabricated films exhibited outstanding superhydrophobic property with a water contact angle 167° and water sliding angle lower than 4°. The developed superhydrophobic surface showed excellent corrosion resistance with insignificant decrease of water contact angle 166° in 3.5 wt.% NaCl solution. This stable highly hydrophobic performance of the fluorinated graphene films could be useful in self-cleaning, antifogging, corrosion resistive coatings and microfluidic devices.

scholarly journals Strength and Water-Repelling Properties of Cement Mortar Mixed with Water Repellents

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5407
Author(s):  
Hyeju Kang ◽  
Sukpyo Kang ◽  
Byoungky Lee
Keyword(s):  
Contact Angle ◽  
Compressive Strength ◽  
Water Contact Angle ◽  
Cement Mortar ◽  
Contact Angles ◽  
Water Repellent ◽  
Water Contact ◽  
Rapid Hardening ◽  
Before And After ◽  
Large Water

In this study, the compressive strength and water contact angle of mortar specimens prepared by mixing two types of water repellent with ordinary Portland cement (OPC) and rapid-hardening cement mortar were measured before and after surface abrasion. In addition, the hydration products and chemical bonding of cement mortar with the repellents were examined using X-ray diffraction (XRD), thermogravimetry-differential thermal analysis (TG-DTA), and Fourier-transform infrared spectroscopy (FT-IR) to evaluate the performance of these cement mortar mixtures as repair materials. We found that the fast-hardening cement mortar mixture containing the oligomer water repellent showed the best performance with a high compressive strength and large water contact angle. With the oligomer water repellent, the rapid-hardening cement mortar mixture showed contact angles of 131° and 126° even after a 2 mm abrasion, thereby confirming that the water repellent secured hydrophobicity through strong bonding with the entire cement mortar as well as its surface. The compressive strengths were found to be 34.5 MPa at 3 h and 54.8 MPa at 28 days, confirming that hydration occurred well despite the addition of water repellent.

Water-Contact-Angle Studies of Fabrics Radiation-Grafted with Methylhydrogensiloxane

1977 ◽  
Vol 47 (2) ◽  
pp. 87-91 ◽  
Author(s):  
Shinko Nishide ◽  
Harumichi Shimizu
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Unit Area ◽  
Contact Angles ◽  
Radiation Grafting ◽  
Water Contact ◽  
Petroleum Solvent ◽  
Solvent Washing

The water-contact angles of the polymethylhydrogensiloxane (silicone)-grafted fabrics (wool, cotton, Vinylon, rayon, acetate, Tetoron, nylon, and silk) prepared by irradiation were measured and the results support the following conclusions: 1. For the same degree of grafting, the relation between the water-contact angles and the roughness factors (defined as the number of yarn crossover points per-unit-area) of various fabrics is linear. It is concluded that the surfaces of grafted fabrics are in the same state regardless of kinds of fabrics. 2. On fabrics of the same roughness the water-contact angles of grafted samples are greater by about 10° than those of the silicone-coated samples, which are padded with silicone, not irradiated, and heated. This fact can be explained by the hypothesis that the upheavals on the surface of a fabric are increased by radiation grafting. 3. By repeated washing with petroleum solvent, the water-contact angles of grafted fabrics decrease a few degrees after one washing and then do not change further even after repeated washing. This result suggests that the grafted silicone is “set” into a conformation which is not appreciably altered in spite of repeated solvent washing.

The Study on the Synthesis of Polyfluoroacrylate

2013 ◽  
Vol 395-396 ◽  
pp. 351-354
Author(s):  
Qin Huan Yang
Keyword(s):  
Contact Angle ◽  
Particle Size ◽  
Polymer Film ◽  
Water Contact Angle ◽  
Film Surface ◽  
Contact Angles ◽  
Fluoride Content ◽  
Water Contact ◽  
Copolymer Films ◽  
High Fluoride

Cationic polyfluoroacrylate has been synthesized in the dual presence of cationic and non-ionic emulsifiers. Optimization studies indicated that the optimal proportions of cationic emulsifier 1631 and non-ionic emulsifiers FSA and AEO-9 were 1.75%, 1.25%, and 0.08%, respectively. Under these conditions, the conversion to the polymer was 92.5%, the particle size was 142 nm, and the water contact angle on a polymer film surface was 94.0°. With increasing dosage of hydrocarbon emulsifier, the water contact angles of copolymer films decreased dramatically. The magnitude of this decrease for a polymer with low fluoride content was greater than that for a polymer with high fluoride content. The fluorinated emulsifier FSA behaved similarly to the hydrocarbon emulsifier.

scholarly journals Experimental approach towards the water contact angle value on the biomaterial alloy Ti6Al4V

2015 ◽  
Vol 70 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Margarita Hierro-Oliva ◽  
Amparo Maria Gallardo-Moreno ◽  
Abraham Rodríguez-Cano ◽  
Jose Morales Bruque ◽  
Maria Luisa González-Martín
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Contact Angles ◽  
Ti6al4v Alloy ◽  
Surrounding Water ◽  
Water Contact ◽  
Large Dispersion ◽  
Biomaterial Surface ◽  
Average Water ◽  
Orthopedic Applications

AbstractIn the biomedical field, water contact angle is a useful gauge to follow how a biomaterial surface would interact with the surrounding water-like physiological environment. Ti6Al4V alloy is widely used in orthopedic applications. Nevertheless, the values of its water contact angle reported in the literature show a large dispersion, from 40° up 80°. However, in addition to the expected dependence of the surface wettability on preliminary treatments, the values of the water contact angle on the pristine Ti6Al4V alloy suffers from an important variability and lack of reproducibility. The present research pays attention to this difficulty and proposes a simple experimental procedure to ensure adequate contact angle reproducibility. Controlled passivation growth in mild underwater conditions of freshly polished disks, followed by ultrasonic washing, avoiding the rubbing of the surface, gives average water contact angles of 80° with very low standard deviations also among samples from the same batch.

scholarly journals Fabrication of a Simultaneous Highly Transparent and Highly Hydrophobic Fibrous Films

2021 ◽  
Vol 11 (12) ◽  
pp. 5565
Author(s):  
Doo-Hyeb Youn ◽  
Kyu-Sung Lee ◽  
Sun-Kyu Jung ◽  
Mangu Kang
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Water Contact Angle ◽  
Electrospun Fiber ◽  
Contact Angles ◽  
Light Transmittance ◽  
Electrospun Fibers ◽  
Water Contact ◽  
Aligned Fibers ◽  
Highly Hydrophobic

This paper discusses the fabrication and characterization of electrospun nanofiber scaffolds made of polystyrene (PS). The scaffolds were characterized in terms of their basis material molecular weight, fiber diameter distribution, contact angles, contact angle hysteresis, and transmittance. We propose an aligned electrospun fiber scaffold using an alignment tool (alignment jig) for the fabrication of highly hydrophobic (θW > 125°) and highly transparent (T > 80.0%) films. We fabricated the alignment jig to align the electrospun fibers parallel to each other. The correlation between the water contact angles and surface roughness of the aligned electrospun fibers was investigated. We found that the water contact angle increased as the surface roughness was increased. Therefore, the hydrophobic properties of the aligned electrospun fibers were enhanced by increasing the surface roughness. With the change in the electrospinning mode to produce aligned fibers rather than randomly distributed fibers, the transmittance of the aligned electrospun fibers increased. The increase in the porous area, leading to better light transmittance in comparison to randomly distributed light scattering through the aligned electrospun fibers increased with the fibers. Through the above investigation of electrospinning parameters, we obtained the simultaneous transparent (>80%) and hydrophobic (θW > 140°) electrospun fiber scaffold. The aligned electrospun fibers of PS had a maximum transmittance of 91.8% at the electrospinning time of 10 s. The water contact angle (WCA) of the aligned electrospun fibers increased from 77° to 141° as the deposition time increased from 10 s to 40 s. The aligned fibers deposited at 40 s showed highly hydrophobic characteristics (θW > 140°).

Wetting Behaviors of an Underwater Oil Droplet on Structured Surfaces

MRS Advances ◽  
2016 ◽  
Vol 1 (10) ◽  
pp. 667-673 ◽  
Author(s):  
Shuai Chen ◽  
Jiadao Wang ◽  
Darong Chen
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Contact Angles ◽  
Silicon Surfaces ◽  
Water Contact ◽  
Structured Surfaces ◽  
Oil Droplet ◽  
Simulation Results ◽  
Dynamics Simulations ◽  
Wetting Behaviors

ABSTRACTIn this study, the wetting behaviors of an underwater oil droplet on structured surfaces were investigated using molecular dynamics simulations and experiments. The wetting states and contact angles of the underwater oil droplet on different hydrophobic surfaces were simulated. The simulation results showed that there were three kinds of equilibrium states on the pillar surfaces: the Wenzel, cross, and Cassie states. Moreover, the equilibrium state of the underwater oil droplet transformed from a Wenzel to Cassie state when the water contact angle decreased. The contact angle of the underwater oil droplet increased as the water contact angle decreased. Furthermore, the wetting behaviors of the underwater oil droplet on rough polytetrafluoroethylene and silicon surfaces were studied in experiments. The experimental results also indicated that the contact angle of the underwater oil droplet increased as the water contact angle decreased, which corresponded well with the simulation results.

scholarly journals Experimental Study of the Influence of the Adsorbate Layer Composition on the Wetting of Different Substrates with Water

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Michaela Heier ◽  
Rolf Merz ◽  
Stefan Becker ◽  
Kai Langenbach ◽  
Michael Kopnarski ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Contact Angles ◽  
Water Contact ◽  
X Ray ◽  
Cleaning Agents ◽  
Adsorbate Layer ◽  
Titanium Substrates ◽  
Layer Composition

Wetting is strongly influenced by adsorbate layers, which are omnipresent on surfaces. The influence of the composition and thickness of adsorbate layers on the water contact angle of sessile drops on different substrates was systematically investigated in the present work. Measurements were carried out for gold-sputtered substrates. These new results are compared to results from a previous study, in which corresponding measurements were carried out for technical steel and titanium substrates. In all experiments, different pretreatments of the samples were used to obtain variations of the adsorbate layer. The samples were either exposed to an oil bath or not, and different cleaning agents were used. The analysis of the adsorbate layer was carried out with X-ray photoelectron spectroscopy (XPS). The results for the different substrates reveal that the water contact angle depends mainly on the composition of the adsorbate layer. The substrate has only an indirect influence, as it influences the composition of the adsorbate layer. The thickness of the adsorbate layers was between 1.4 and 14 nm and was large enough to prevent a direct influence of the substrate on the water contact angle. It is shown that using the information on the adsorbate layer composition from XPS and the results for the water contact angle obtained for the gold samples alone, the water contact angles on the steel and titanium samples can be predicted.

Enhancing the Superhydrophobic Behavior of Electrospun Fibers via Graphene Addition and Heat Treatment

2010 ◽  
Author(s):  
M. Ceylan ◽  
R. Asmatulu
Keyword(s):  
Heat Treatment ◽  
Contact Angle ◽  
Water Contact Angle ◽  
Fiber Surface ◽  
Electrospun Nanofibers ◽  
Contact Angles ◽  
Polymeric Fibers ◽  
Electrospinning Technique ◽  
Water Contact ◽  
Nanocomposite Fibers

Polyvinyl chloride (PVC) fibers incorporated with graphene nanoflakes were produced using electrospinning technique, and then superhydrohobicity of the electrospun nanofibers were investigated as a function of inclusion and temperature. In the absence of graphene, water contact angle of the fibers is below 140°; however, the water contact angle values of 0.5, 1, 2 and 4% graphene in fibers become 142, 152, 165 and 166°, respectively. Using a heat treatment, the contact angle values of samples also increase up to glass transition temperature of PVC. This indicates that graphene inclusions in the polymeric fibers and temperature drastically change the surface morphology and chemistry, which results in higher contact angles. The reason behind this phenomena may be the formation of smaller nanosized graphene bumps on the fiber surface that make the contact area between the droplet and the fiber extremely small. As a result, this process minimizes attractive forces between the water molecules and surface atoms of the rough nanocomposite fibers to bead up and rolls off.

Sign in / Sign up

Export Citation Format

Share Document