scholarly journals Silica Based Superhydrophobic Nanocoatings for Natural Rubber Surfaces

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Veromee Kalpana Wimalasiri ◽  
Helapiyumi Uthpala Weerathunga ◽  
Nilwala Kottegoda ◽  
Veranja Karunaratne
Keyword(s):  
Natural Rubber ◽  
Imaging Techniques ◽  
Spray Coating ◽  
Surface Functional Groups ◽  
Sliding Angle ◽  
Water Contact ◽  
Force Microscopy ◽  
Superhydrophobic Coatings ◽  
Atomic Force ◽  
Coating Methods

Silica based nonfluorinated superhydrophobic coatings for natural rubber surfaces have been developed. The coating was synthesized using nanosilica dispersion and a polychloroprene type binder as a compatibilizer. This nanocoating of silica was applied on to the surface of finished natural rubber gloves, by spray coating or dipped coating methods. The nanocoating demonstrates a water contact angle of more than 150° and sliding angle of 7°. The morphological features of the coating have been studied using scanning electron microscopy and atomic force microscopy while Fourier transform infrared spectroscopy was used to understand the nature of surface functional groups. Both imaging techniques provided evidence for the presence of nanosized particles in the coating. Coated gloves demonstrated comparable mechanical properties and significantly better alcohol resistivity when compared to those of the uncoated gloves.

scholarly journals Dip-Coating Approach to Fabricate Durable PDMS/STA/SiO2 Superhydrophobic Polyester Fabrics

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 326
Author(s):  
Xiaoli Liu ◽  
Youcai Gu ◽  
Tengfei Mi ◽  
Xiaomei Wang ◽  
Xu Zhang
Keyword(s):  
Contact Angle ◽  
Textile Industry ◽  
Dip Coating ◽  
Water Contact ◽  
Force Microscopy ◽  
Superhydrophobic Coatings ◽  
Atomic Force ◽  
High Durability ◽  
Coating Method ◽  
Dip Coating Method

The facile, simple, highly efficient, and fluorine-free fabrication of superhydrophobic surfaces on fabrics with high durability has attracted considerable attention because of its urgent practical application. The simple dip-coating method was adopted to make a stable and durable polydimethylsiloxane/stearic acid/silica (PDMS/STA/SiO2) superhydrophobic fabric. The fabric’s surface morphology, roughness, and composition were analyzed by scanning electron microscopy, atomic force microscopy, and Fourier transform infrared spectroscopy, respectively. The PDMS/STA/SiO2-coated fabric: demonstrated strong superhydrophobicity (a water contact angle (WCA) of around 163°), efficiently repelled different liquids (milk, coffee, orange juice, Coca-Cola, and 1 M of HCl and NaOH) with a contact angle above 155°, had excellent self-cleaning performance, and retained superhydrophobicity with a WCA greater than 150° after 72 h of ultraviolet irradiation and 700 cycles of mechanical abrasion. The PDMS/STA/SiO2 coating had few influences on the color fastness of the fabric. Superhydrophobic coatings are expected to be practically applied in the textile industry.

scholarly journals Stable and Durable Conductive Superhydrophobic Coatings Prepared by Double-Layer Spray Coating Method

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1506
Author(s):  
Xiang Liu ◽  
Kai Chen ◽  
Dekun Zhang ◽  
Zhiguang Guo
Keyword(s):  
Composite Coating ◽  
Double Layer ◽  
Low Cost ◽  
Spray Coating ◽  
Sliding Angle ◽  
Water Contact ◽  
Superhydrophobic Coatings ◽  
Coating Method ◽  
Specialty Fields ◽  
Application Fields

Herein, a low cost, durable, and stable conductive superhydrophobic composite coating (CSC coating) was fabricated on a Q345 steel surface by simple double-layer spray coating. The water contact angle (WCA) of the CSC coating was 160° and the sliding angle (SA) was 3°. In addition to its excellent conductivity (3.10 × 103 Ω), the fabricated composite coating had good durability and wear resistance. After 10 sand-washing cycles, the CSC coating surface still exhibited stable superhydrophobicity (149° WCA, 9.5° SA). At 200 g pressure, the surface of the optimized CSC coating still maintained fine superhydrophobicity (150° WCA, 9.2° SA) and conductivity (1.86 × 104 Ω) after 10 abrasion cycles. In addition, it also exhibited fine adhesion (0.307 MPa) between the composite coating and the substrate. This functional superhydrophobic surface can be applied in specialty fields with harsh conditions such as coal mining and petrochemical activities. This new coating may also expand the application fields of superhydrophobic surfaces and have broad practical application prospects.

Development of leftover rice/gelatin interpenetrating polymer network films for food packaging

2021 ◽  
Vol 10 (1) ◽  
pp. 37-48
Author(s):  
Sijia Li ◽  
Chun Shao ◽  
Zhikun Miao ◽  
Panfang Lu
Keyword(s):  
Food Packaging ◽  
Polymer Network ◽  
Raw Material ◽  
Interpenetrating Polymer Network ◽  
Waste Biomass ◽  
Practical Application ◽  
Water Contact ◽  
Force Microscopy ◽  
Atomic Force ◽  
Morphology Of Films

Abstract Waste biomass can be used as a raw material for food packaging. Different concentrations of gelatin (GEL) were introduced into the leftover rice (LR) system to form an interpenetrating polymer network (IPN) for improving the properties of the films. The structure and morphology of films were evaluated by Fourier transform infrared, scanning electron microscopy, and atomic force microscopy, which showed good compatibility between LR and GEL. The moisture content and oil absorption rate of IPN films were down by 105% and 182%, respectively, which showed better water and oil resistance than the LR film. In addition, increasing GEL concentration led to enhancement in the tensile strength of films from 2.42 to 11.40 MPa. The water contact angle value of the IPN films (117.53°) increased by 147% than the LR film (47.56°). The low haze of IPN films was obtained with the increment of the mutual entanglement of LR and GEL. The 30–50% GEL addition improved the water vapor barrier and thermal stability properties of the IPN films. This study highlights that LR as waste biomass can have a practical application in food packaging.

scholarly journals Synthesis of amphiphilic ABA triblock oligomer via ATRP and its surface properties

2017 ◽  
Vol 95 (5) ◽  
pp. 605-611 ◽  
Author(s):  
Lei Wang ◽  
Shaoqing Wen ◽  
Zhanxiong Li
Keyword(s):  
Photoelectron Spectroscopy ◽  
Microphase Separation ◽  
Gel Permeation Chromatography ◽  
Contact Angles ◽  
Chemical Compositions ◽  
Water Contact ◽  
Force Microscopy ◽  
Atomic Force ◽  
Poly Ethylene ◽  
Magnetic Resonances

A series of novel amphiphilic ABA-type poly(tridecafluorooctylacrylate)-poly(ethylene glycol)-poly(tridecafluorooctylacrylate) (henceforth referred to as p-TDFA-PEG-p-TDFA) triblock oligomers were successfully synthesized via atom transfer radical polymerization (ATRP) using well-defined Br-PEG-Br as macroinitiator and copper as catalyst. The block oligomers were characterized by Fourier transform infrared (FTIR) spectroscopy and 1H and 19F nuclear magnetic resonances (NMR). Gel permeation chromatography (GPC) showed that the block oligomers have been obtained with narrow molecular weight distributions of 1.22–1.33. X-ray photoelectron spectroscopy (XPS) was carried out to confirm the attachment of p-TDFA-PEG-p-TDFA onto the silicon substrate, together with the chemical compositions of p-TDFA-PEG-p-TDFA. The wetabilities of the oligomer films were measured by water contact angles (CAs). Water CAs of p-TDFA-PEG-p-TDFA film were measured and their morphologies were tested by atomic force microscopy (AFM). The result showed that the CAs of the oligomer films, which possess fluoroalkyl groups assembled on the outer surface, increase after heating due to the migration of fluoroalkyl groups and the resulted microphase separation of the p-TDFA-PEG-p-TDFA.

scholarly journals Abrasion Resistance of Superhydrophobic Coatings on Aluminum Using PDMS/SiO2

Coatings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 414 ◽  
Author(s):  
Divine Sebastian ◽  
Chun-Wei Yao ◽  
Ian Lian
Keyword(s):  
Silica Nanoparticles ◽  
Abrasion Resistance ◽  
Functionalized Silica ◽  
Surface Chemical ◽  
X Ray ◽  
Force Microscopy ◽  
Surface Chemical Composition ◽  
Superhydrophobic Coatings ◽  
Atomic Force ◽  
High Contact Angle

Superhydrophobic coatings have shown tremendous improvement in the usability of metals such as aluminum. These coatings are capable of adding attractive features such as self-cleaning, anti-corrosion, and anti-biofouling to the array of diverse features that aluminum possesses, including lightweight and high ductility. For superhydrophobic surfaces, having considerable abrasion resistance is as important as achieving a high contact angle. In this work, two types of coatings have been prepared, each composed of functionalized silica nanoparticles along with polydimethylsiloxane (PDMS) dispersed in ethanol, and their superhydrophobicity and abrasion characteristics have been investigated. The same silica nanoparticles are present in each coating, but each has a different proportion of the PDMS base to its curing agent. The surface morphology of the coatings was studied with the aid of a scanning electron microscope (SEM) and an atomic force microscope (AFM). The surface chemical composition was characterized using an energy dispersive X-ray spectroscope (EDX). The prepared coatings were analyzed for their degree of superhydrophobicity, abrasion resistance and adhesion characteristics. In addition, atomic force microscopy was used to understand the adhesion characteristics of the coatings.

The Investigation of Thin Protecting Layers on Roughened Galvanized Steel Surfaces Produced by Different Coating Methods

2008 ◽  
Vol 589 ◽  
pp. 433-438 ◽  
Author(s):  
Péter Németh ◽  
Ágnes Csanády ◽  
Katalin Papp ◽  
Anna C. Pintér ◽  
László Szabó ◽  
...  
Keyword(s):  
Thickness Distribution ◽  
Thin Layers ◽  
Galvanized Steel ◽  
Photoemission Spectroscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Coating Methods ◽  
Chemical States ◽  
Steel Surfaces ◽  
Thickness Variations

Protective, chromate substitute thin layers on roughened galvanized surfaces produced at OCAS (Arcelor, Belgium) were characterized and compared using Scanning Electron Microscopy (SEM+EDS), Atomic Force Microscopy (AFM), Nanoindentation and X-ray Photoemission Spectroscopy (XPS). EDX maps, line scans and point analyses obtained at various places of the surfaces have shown differences between the CVD and silane nanolayers in the matter of thickness distribution and composition. At cross-section specimens the thickness of the layers could be shown. The hardness differences caused by layer thickness variations are hard to follow by nanoindentation as the penetration depth of the indenter is much larger than the thickness of the coatings. XPS measurements can distinguish between the chemical states of silicon in CVD and silane coatings.

scholarly journals Superhydrophilic Coating with Antibacterial and Oil-Repellent Properties via NaIO4-Triggered Polydopamine/Sulfobetaine Methacrylate Polymerization

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2008
Author(s):  
Hsiu-Wen Chien ◽  
Hong-Yu Lin ◽  
Chau-Yi Tsai ◽  
Tai-Yu Chen ◽  
Wei-Nian Chen
Keyword(s):  
Surface Modification ◽  
Photoelectron Spectroscopy ◽  
Deposition Process ◽  
Water Contact ◽  
Water Separation ◽  
Force Microscopy ◽  
Atomic Force ◽  
Oil Water Separation ◽  
One Step ◽  
Oil Repellent

Superhydrophilic coatings have been widely used for the surface modification of membranes or biomedical devices owing to their excellent antifouling properties. However, simplifying the modification processes of such materials remains challenging. In this study, we developed a simple and rapid one-step co-deposition process using an oxidant trigger to fabricate superhydrophilic surfaces based on dopamine chemistry with sulfobetaine methacrylate (SBMA). We studied the effect of different oxidants and SBMA concentrations on surface modification in detail using UV–VIS spectrophotometry, dynamic light scattering, atomic force microscopy, X-ray photoelectron spectroscopy, and surface plasmon resonance. We found that NaIO4 could trigger the rate of polymerization and the optimum ratio of dopamine to SBMA is 1:25 by weight. This makes the surface superhydrophilic (water contact angle < 10°) and antifouling. The superhydrophilic coating, when introduced to polyester membranes, showed great potential for oil/water separation. Our study provides a complete description of the simple and fast preparation of superhydrophilic coatings for surface modification based on mussel-inspired chemistry.

scholarly journals Silver Nanoparticles Embedded in Natural Rubber Films: Synthesis, Characterization, and Evaluation ofIn VitroToxicity

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Caroline S. Danna ◽  
Dalita G. S. M. Cavalcante ◽  
Andressa S. Gomes ◽  
Leandra E. Kerche-Silva ◽  
Eidi Yoshihara ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Natural Rubber ◽  
Chinese Hamster ◽  
Cell Lineage ◽  
Microscopic Analysis ◽  
Visible Spectrum ◽  
Electron Microscopic ◽  
Force Microscopy ◽  
Atomic Force

Natural rubber (NR) films can reduce silver metal ions forming embedded metal nanoparticles, a process that could be described as green synthesis. The NR films acting as a reactor generate and incorporate silver nanoparticles (AgNPs). Organic acids and amino acids play a crucial role in the formation of AgNPs. The plasmon extinction obtained in the UV-visible spectrum shows the presence of nanoparticles in the film after dipping the NR film into a solution of silver nitrate at 80°C. Electron microscopic analysis confirms the presence of AgNPs in the NR film and characterization by atomic force microscopy shows a change in the roughness of the NR film with AgNPs. In addition, our preliminary results fromin vitrotoxicity studies (MTT and comet assays) of the NR films and NR films with silver nanoparticles (NR/Ag) show that they are not toxic to cell lineage CHO-K1 (cells from the ovary of a Chinese hamster), an important result for potential medical applications.

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