scholarly journals Preparation of CNF/PDMS Superhydrophobic Coatings with Good Abrasion Resistance Using a One-Step Spray Method

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5380
Author(s):  
Jingda Huang ◽  
Peihao Cai ◽  
Mengmeng Li ◽  
Qiang Wu ◽  
Qian Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Abrasion Resistance ◽  
Substrate Surface ◽  
Cellulose Nanofibers ◽  
Scratch Resistance ◽  
Water Contact ◽  
Preparation Methods ◽  
Superhydrophobic Coatings ◽  
Spray Method ◽  
Complex Preparation

Complex preparation methods and weak mechanical properties of superhydrophobic coatings hinder their applicability. To address these problems, cellulose nanofibers (CNFs) were used as structural materials to augment the roughness properties, while polydimethylsiloxane (PDMS) was used as the adhesive. Based on the results of previous studies, superhydrophobic coatings with good mechanical properties can be prepared by spraying the mixture onto a substrate surface; herein, the mixture comprised modified CNFs and PDMS. The resulting coating possessed excellent superhydrophobicity, which allowed a maximum water contact angle (WCA) of 158°. Furthermore, it exhibited great knife-scratch-resistance properties and good abrasion performance, which was evaluated by abrading with 800-grit sandpaper for 19 cycles (abrasion length of 380 cm) under a 100 g load. Based on the simple operation and abrasion resistance, the coating shows great potential for practical application.

scholarly journals The influence of surface finishing of Paulownia Siebold et Zucc. on the mechanical properties of lacquered surface

2010 ◽  
pp. 7-23
Author(s):  
Milan Jaic ◽  
Jovan Dobic ◽  
Tanja Palija
Keyword(s):  
Mechanical Properties ◽  
Abrasion Resistance ◽  
Scratch Resistance ◽  
Surface Finishing ◽  
Coating Application ◽  
Acrylic Coating ◽  
Acrylic Coatings ◽  
Paulownia Fortunei ◽  
Free Falling ◽  
Paulownia Elongata

This paper presents the research of influence of sanding, staining and the use of polyurethane and acrylic coating on the adhesion, scratch resistance and abrasion resistance of the coating. Objective was to determine the most important mechanical properties of lacquered surfaces, considering the application of Paulownia elongata and Paulownia fortunei, by using different systems of surface finishing. Cross cut method was used for measurement of adhesion. More accurate view of coating adhesion was obtained by measuring the scratch resistance. Abrasion resistance was tested by the method of free falling of abrasive particles. The applied system of sanding had no effect on the examined mechanical properties. Stained samples lacquered with PU coating showed better adhesion to the non-stained samples. Impact of staining on scratch resistance is not established. Stained samples showed greater resistance to abrasion for both wood species. Samples lacquered with PU coating showed the higher values of mechanical properties compared with samples lacquered with UV acrylic coating. Application of PU coating for surface finishing of Paulownia elongata and Paulownia fortunei is more adequate than the application of UV acrylic coatings, from the point of scratch resistance and abrasion resistance.

scholarly journals The impact of the top coating on the mechanical properties of lacquered wood surfaces

2012 ◽  
pp. 87-100
Author(s):  
Milan Jaic ◽  
Tanja Palija
Keyword(s):  
Mechanical Properties ◽  
Wood Species ◽  
Abrasion Resistance ◽  
Direct Contact ◽  
Quercus Robur ◽  
Scratch Resistance ◽  
Indentation Hardness ◽  
Polyurethane Coating ◽  
The Impact ◽  
Wood Surfaces

This paper investigates the impact of the top coating on the basic mechanical properties of a lacquered surface, including indentation hardness, scratch resistance and abrasion resistance. Three types of the top coating were used, including a 2K polyurethane coating, a 2K acrylate-isocyanate coating and a 2K alkyd-urethane coating. Samples of two wood species, spruce (Picea abies Karst.) and oak (Quercus robur L.), were used in this study, in order to determine whether the wood species, which is not in direct contact with the top coating, has an impact on the mechanical properties of a lacquered surface. The samples coated with a 2K acrylate-isocyanate coating showed the highest values of indentation hardness, in the samples of both wood species (1.34 N for spruce; 1.4 N for oak). The samples coated with a 2K alkyd-urethane coating showed the highest values of scratch resistance (20 N for both wood species) and abrasion resistance (mass loss of 480 mg after 700 cycles for both wood species). The results have shown that the wood species does not affect the value of indentation hardness, scratch resistance and abrasion resistance of a lacquered surface.

scholarly journals Investigation of the Effects of Component Ratios on the Properties of Superhydrophobic Polyurethane/Fluorinated Acrylic Co-Polymer/SiO2 Nanocomposite Coatings

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 174
Author(s):  
Chong Ke ◽  
Zhongfa Li ◽  
Chenhua Zhang ◽  
Xinguo Wu ◽  
Zhiping Zhu ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Abrasion Resistance ◽  
Light Transmittance ◽  
Practical Application ◽  
Water Contact ◽  
Glass Substrates ◽  
Superhydrophobic Coatings ◽  
One Step ◽  
Good Transparency

In this work, polyurethane/fluorinated acrylic co-polymer/silicon dioxide (PU/FAP/SiO2) hybrid superhydrophobic coatings were fabricated on glass substrates via a simple one-step coating process. The effects of each coating component on the coating properties were systematically investigated. The optimized coating exhibits a water contact angle (WCA) of 159° and a rolling angle of 3°. Meanwhile, the coating has an optical light transmittance of 88%, indicating the good transparency of the coating. Besides, the coating demonstrates an adequate level of abrasion resistance. After a total abrasion distance of 300 cm against a piece of 800 mesh sand paper, the sample still kept a water contact angle of about 110°, showing its high abrasion resistance. Therefore, the optimized coating has a great potential for practical application.

scholarly journals Effect of pectin extraction method on properties of cellulose nanofibers isolated from sugar beet pulp

2021 ◽  
Author(s):  
Mohammad L Hassan ◽  
Linn Berglund ◽  
Wafaa S Elseoud ◽  
Enas A Hassan ◽  
Kristiina Oksman
Keyword(s):  
Mechanical Properties ◽  
Sugar Beet ◽  
Extraction Method ◽  
Cellulose Nanofibers ◽  
Contact Angles ◽  
Degree Of Polymerization ◽  
Sugar Beet Pulp ◽  
Cellulose Content ◽  
Water Contact ◽  
Beet Pulp

Abstract In this study, the effect of pectin extraction method on the properties of cellulose nanofibers (CNFs) isolated from sugar beet pulp (SBP) was studied. Pectin was extracted by the industrially practiced method by sulfuric acid hydrolysis or by enzymatic hydrolysis using a cellulase/xylanase enzymes mixture. The CNFs were then isolated by high-pressure homogenization and investigated in terms of their chemical composition, crystallinity, size, degree of polymerization, and re-dispersion in water after freeze-drying. The mechanical properties and surface characteristics of CNFs films were also studied. The results showed that fibrillation of the de-pectinated SBP was more efficient for the acid hydrolyzed SBP. CNFs from the acid-hydrolyzed SBP had a slightly wider diameter, higher crystallinity, viscosity, and α-cellulose content but a lower degree of polymerization than CNFs from the enzyme-hydrolyzed SBP. Owing to the presence of more residual hemicelluloses in the CNFs from the enzyme-hydrolyzed SBP, the CNFs had higher re-dispersion ability in water. CNFs films from enzyme-hydrolyzed SBP displayed slightly better mechanical properties and higher water contact angles than acid-hydrolyzed CNF films.

Effect of chemical modification on slip resistance and mechanical properties of rubber

2015 ◽  
Vol 35 (2) ◽  
pp. 119-125
Author(s):  
Ranganathan Mohan ◽  
Raja Sundaresan ◽  
Bhabendra Nath Das
Keyword(s):  
Mechanical Properties ◽  
Surface Modification ◽  
Photoelectron Spectroscopy ◽  
Abrasion Resistance ◽  
Material Design ◽  
Surface Modifications ◽  
Vertical Force ◽  
Water Contact ◽  
Slip Resistance ◽  
Surface Modified

Abstract Shoe sole material, design, tread pattern and surface modifications influence slip resistance while walking and running. Thermoplastic styrene-butadine-styrene rubber, commercially known as TPR, is one of the materials widely used as shoe soles. This type of sole is subjected to chemical treatment known as halogenation to increase adhesion characteristic with the upper. The coefficient of friction (COF) is the ratio between the horizontal force and the vertical force when tested with the help of slip resistance test equipment SATRA STM 603. It is also known that footwear outsole surface modification affects COF at the footwear floor interfaces. In this study, plain TPR shoe sole samples were surface modified by treating with 2.0 wt% trichloroisocyanuric acid (TCI) in methyl ethyl ketone (MEK). The effect of surface modifications was studied by water contact angle measurements, Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS), surface roughness and scanning electron microscopy (SEM). The surface modified sole samples were also tested for other mechanical properties such as tensile strength, elongation at break, hardness and abrasion resistance to find out the extent of changes in those essential functional properties. It was observed that surface modification of TPR sole increased COF and reduced strength, elasticity and abrasion resistance properties. However, there was no significant change in hardness.

scholarly journals Effect of pectin extraction method on properties of cellulose nanofibers isolated from sugar beet pulp

Cellulose ◽  
2021 ◽  
Author(s):  
Mohammad L. Hassan ◽  
Linn Berglund ◽  
Wafaa S. Abou Elseoud ◽  
Enas A. Hassan ◽  
Kristiina Oksman
Keyword(s):  
Mechanical Properties ◽  
Sugar Beet ◽  
Extraction Method ◽  
Cellulose Nanofibers ◽  
Degree Of Polymerization ◽  
Sugar Beet Pulp ◽  
Cellulose Content ◽  
Water Contact ◽  
Beet Pulp ◽  
Cnf Films

AbstractIn this study, the effect of pectin extraction method on the properties of cellulose nanofibers (CNFs) isolated from sugar beet pulp (SBP) was studied. Pectin was extracted by the industrially practiced method by sulfuric acid hydrolysis or by enzymatic hydrolysis using a cellulase/xylanase enzymes mixture. The CNFs were then isolated by high-pressure homogenization and investigated in terms of their chemical composition, crystallinity, size, degree of polymerization, and re-dispersion in water after freeze-drying. The mechanical properties and surface characteristics of CNF films were also studied. The results showed that fibrillation of the de-pectinated SBP was more efficient for the acid hydrolyzed SBP. CNFs from the acid-hydrolyzed SBP had a slightly wider diameter, higher crystallinity, viscosity, and α-cellulose content but a lower degree of polymerization than CNFs from the enzyme-hydrolyzed SBP. Owing to the presence of more residual hemicelluloses in the CNFs from the enzyme-hydrolyzed SBP, the CNFs had higher re-dispersion ability in water. CNF films from enzyme-hydrolyzed SBP displayed slightly better mechanical properties and higher water contact angle than acid-hydrolyzed CNF films. Graphic abstract

Characterization of “Green” Composites Reinforced by Cellulose Nanofibers

2007 ◽  
Vol 334-335 ◽  
pp. 389-392 ◽  
Author(s):  
Hitoshi Takagi ◽  
Akira Asano
Keyword(s):  
Mechanical Properties ◽  
Flexural Modulus ◽  
Cellulose Nanofibers ◽  
Molding Pressure ◽  
Green Composites ◽  
Mixing Process ◽  
Environment Friendly ◽  
Preparation Methods ◽  
Uniform Dispersion

Environment-friendly “green” composites were fabricated from a starch-based, dispersion-type biodegradable resin and cellulose nanofibers. The mixture of the dispersion-type biodegradable resin and cellulose nanofibers were blended well by using a home-use mixer and a stirrer, and then dried in air or in a vacuum. Composites were prepared by conventional hot pressing at a constant temperature of 140°C and at pressures from 10 to 50 MPa. Their flexural strength as well as flexural modulus increased with increasing the molding pressure, and were also affected by preparation methods and conditions. Their mechanical properties such as strength and modulus had a good correlation with their density. Especially it can be seen that there is significant effectiveness in a stirrer mixing process, which results in the improved uniform dispersion of nanofibers.

scholarly journals High Transmittance Superhydrophobic Coatings with Durable Self-Cleaning Properties

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 493
Author(s):  
Michele Ferrari ◽  
Paolo Piccardo ◽  
Justine Vernet ◽  
Francesca Cirisano
Keyword(s):  
Power Plants ◽  
Spray Coating ◽  
Dust Particles ◽  
Water Contact ◽  
Superhydrophobic Coatings ◽  
Spray Method ◽  
Coating Method ◽  
Solar Power Plants ◽  
Self Cleaning ◽  
The Impact

One of the most important factors determining a significant reduction in optical devices’ efficiency is the accumulation of soiling substances such as dust, which, especially in solar power plants, implies higher costs and materials ageing. The use of superhydrophobic (SH) coatings, water contact angle (CA) greater than 150°, represents a suitable solution to improve the self-cleaning action while at the same time providing high transmittance for energy conversion. A mixed organic–inorganic SH coating with surface roughness below 100 nm was prepared by an easily scalable spray method and employed, allowing us to modulate the covered area and transparency. The coating has been also investigated while simulating pollution agents like acid rain, harsh environments, and the impact of continuous water droplets and dust particles with different physicochemical properties. The spray coating method allows us to obtain a modulated SH and self-cleaning surface showing CA > 170°, high transmittance in UV-Vis range and the ability to completely restore its initial properties in terms of wettability and transmittance after durability and soiling tests.

Cellulose Nanofibrils-based Hydrogels for Biomedical Applications: Progresses and Challenges

2020 ◽  
Vol 27 (28) ◽  
pp. 4622-4646 ◽  
Author(s):  
Huayu Liu ◽  
Kun Liu ◽  
Xiao Han ◽  
Hongxiang Xie ◽  
Chuanling Si ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Metal Ion ◽  
Biomedical Applications ◽  
Biomedical Application ◽  
Cellulose Nanofibrils ◽  
Wound Dressings ◽  
Preparation Methods ◽  
Tissue Scaffold ◽  
Surface Areas ◽  
Mechanical Methods

Background: Cellulose Nanofibrils (CNFs) are natural nanomaterials with nanometer dimensions. Compared with ordinary cellulose, CNFs own good mechanical properties, large specific surface areas, high Young's modulus, strong hydrophilicity and other distinguishing characteristics, which make them widely used in many fields. This review aims to introduce the preparation of CNFs-based hydrogels and their recent biomedical application advances. Methods: By searching the recent literatures, we have summarized the preparation methods of CNFs, including mechanical methods and chemical mechanical methods, and also introduced the fabrication methods of CNFs-based hydrogels, including CNFs cross-linked with metal ion and with polymers. In addition, we have summarized the biomedical applications of CNFs-based hydrogels, including scaffold materials and wound dressings. Results: CNFs-based hydrogels are new types of materials that are non-toxic and display a certain mechanical strength. In the tissue scaffold application, they can provide a micro-environment for the damaged tissue to repair and regenerate it. In wound dressing applications, it can fit the wound surface and protect the wound from the external environment, thereby effectively promoting the healing of skin tissue. Conclusion: By summarizing the preparation and application of CNFs-based hydrogels, we have analyzed and forecasted their development trends. At present, the research of CNFs-based hydrogels is still in the laboratory stage. It needs further exploration to be applied in practice. The development of medical hydrogels with high mechanical properties and biocompatibility still poses significant challenges.

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