Superhydrophobic paper coating containing nonconventional clay

TAPPI Journal ◽  
2010 ◽  
Vol 9 (11) ◽  
pp. 33-40 ◽  
Author(s):  
BEHUDIN (BEKO) MESIC ◽  
CHRISTIAN KUGGE ◽  
LARS JÄRNSTRÖM
Keyword(s):  
Water Absorption ◽  
Cross Sections ◽  
Transmission Rate ◽  
High Water ◽  
Contact Angles ◽  
Water Contact ◽  
Barrier Performance ◽  
Superhydrophobic Paper ◽  
Hydrophobic Clay ◽  
Scanning Electron

Hydrophobic clay fillers have not been widely used in dispersion coatings for linerboard because of the difficulty of dispersing them in water. This work investigated whether hydrophobic clay can be used as filler in barrier dispersion coatings. Hydrophobic clay was compared with conventional clay in terms of coating consolidation, structure, wetting, and barrier performance. All coatings were applied to linerboard sheets made using a laboratory dynamic sheet former. The coated linerboards were examined using scanning electron microscopy and Raman spectroscopy, and were characterized with respect to water absorption, vapor transmission rate, and contact angles. The results show that a coating containing hydrophobic clay provides a superhydrophobic character to paper; i.e., a high water contact angle (150°) and relatively low water absorption. Raman mapping of cross-sections revealed that the latex distribution is uniform in the presence of either conventional clay or hydrophobic clay, and that the distribution of hydrophobic clay tends to be more uniform than conventional clay, which might reflect good mixing and consolidation of hydrophobic clay.

Crosslinked waterborne polyurethane with high waterproof performance

2016 ◽  
Vol 7 (23) ◽  
pp. 3913-3922 ◽  
Author(s):  
Fangfang Yu ◽  
Liwei Cao ◽  
Zhaohui Meng ◽  
Naibo Lin ◽  
Xiang Yang Liu
Keyword(s):  
Thermal Properties ◽  
Water Absorption ◽  
Waterborne Polyurethane ◽  
High Water ◽  
Contact Angles ◽  
Water Contact ◽  
Fluorinated Acrylate ◽  
Waterborne Polyurethanes

Fluorinated acrylate and siloxane waterborne polyurethanes with crosslinked structure exhibit low water absorption, high water contact angles, and high mechanical/thermal properties.

scholarly journals Enhanced Anti-Mold Property and Mechanism Description of Ag/TiO2 Wood-Based Nanocomposites Formation by Ultrasound- and Vacuum-Impregnation

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 682
Author(s):  
Lin Lin ◽  
Jiaming Cao ◽  
Jian Zhang ◽  
Qiliang Cui ◽  
Yi Liu
Keyword(s):  
Electron Microscopy ◽  
Cell Walls ◽  
Mercury Intrusion Porosimetry ◽  
Water Source ◽  
Contact Angles ◽  
Vacuum Impregnation ◽  
Water Contact ◽  
Mercury Intrusion ◽  
Wood Surfaces ◽  
Scanning Electron

Ag/TiO2 wood-based nanocomposites were prepared by the methods of ultrasound impregnation and vacuum impregnation. The as-prepared samples were characterized by field emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), mercury intrusion porosimetry (MIP), and water contact angles (WCAs). The anti-mold properties of the Ag/TiO2 wood-based nanocomposites were improved by 14 times compared to those of the original wood. The nano-Ag/TiO2, which was impregnated in the tracheid and attached to the cell walls, was able to form a two-stage rough structure and reduce the number of hydroxyl functional groups on the wood surfaces. The resulting decline of wood hydrophobic and equilibrium moisture content (EMC) destroyed the moisture environment necessary for mold survival. Ag/TiO2 was deposited in the wood pores, which reduced the number and volume of pores and blocked the path of mold infection. Thus, the anti-mold properties of the Ag/TiO2 wood-based nanocomposite were improved by cutting off the water source and blocking the mold infection path. This study reveals the anti-mold mechanism of Ag/TiO2 wood-based nanocomposites and provides a feasible pathway for wood-based nanocomposites with anti-mold functions.

scholarly journals Polycaprolactone-Chitin Nanofibrous Mats as Potential Scaffolds for Tissue Engineering

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Min Sup Kim ◽  
Sang Jun Park ◽  
Bon Kang Gu ◽  
Chun-Ho Kim
Keyword(s):  
Electron Microscopy ◽  
Tissue Engineering ◽  
Contact Angles ◽  
Dermal Fibroblasts ◽  
Human Dermal Fibroblasts ◽  
Water Contact ◽  
Mean Diameter ◽  
Poly Caprolactone ◽  
Scanning Electron

We describe here the preparation of poly(caprolactone) (PCL)-chitin nanofibrous mats by electrospinning from a blended solution of PCL and chitin dissolved in a cosolvent, 1,1,1,3,3,3-hexafluoro-2-propanol and trifluoroacetic acid. Scanning electron microscopy showed that the neutralized PCL-chitin nanofibrous mats were morphologically stable, with a mean diameter of340.5±2.6 nm, compared with a diameter of524.2±12.1 nm for PCL mats. The nanofibrous mats showed decreased water contact angles as the proportion of chitin increased. However, the tensile properties of nanofibrous mats containing30~50% (wt/wt) chitin were enhanced compared with PCL-only mats.In vitrostudies showed that the viability of human dermal fibroblasts (HDFs) for up to 7 days in culture was higher on composite (OD value:1.42±0.09) than on PCL-only (0.51±0.14) nanofibrous mats, with viability correlated with chitin concentration. Together, our results suggest that PCL-chitin nanofibrous mats can be used as an implantable substrate to modulate HDF viability in tissue engineering.

scholarly journals Facile Approach to Develop Hierarchical Roughness fiber@SiO2 Blocks for Superhydrophobic Paper

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1393 ◽  
Author(s):  
Qing Wang ◽  
Jieyi Xiong ◽  
Guangxue Chen ◽  
Ouyang Xinping ◽  
Zhaohui Yu ◽  
...  
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Sol Gel ◽  
Sio2 Nanoparticles ◽  
Contact Angles ◽  
Preparation Process ◽  
Water Contact ◽  
Mechanical Durability ◽  
Complex Preparation ◽  
Superhydrophobic Paper

Papers with nanoscaled surface roughness and hydrophobically modification have been widely used in daily life. However, the relatively complex preparation process, high costs and harmful compounds have largely limited their applications. This research aims to fabricate superhydrophobic papers with low cost and nontoxic materials. The surface of cellulose fibers was initially coated with a film of SiO2 nanoparticles via sol-gel process. After papermaking and subsequent modification with hexadecyltrimethoxysilane through a simple solution-immersion process, the paper showed excellent superhydrophobic properties, with water contact angles (WCA) larger than 150°. Moreover, the prepared paper also showed superior mechanical durability against 10 times of deformation. The whole preparation process was carried out in a mild environment, with no intricate instruments or toxic chemicals, which has the potential of large-scale industrial production and application.

Supramolecular functionalized polybenzoxazines from azobenzene carboxylic acid/azobenzene pyridine complexes: synthesis, surface properties, and specific interactions

RSC Advances ◽  
2015 ◽  
Vol 5 (17) ◽  
pp. 12763-12772 ◽  
Author(s):  
Mohamed Gamal Mohamed ◽  
Chi-Hui Hsiao ◽  
Kuo-Chih Hsu ◽  
Fang-Hsien Lu ◽  
His-Kang Shih ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Surface Properties ◽  
High Water ◽  
Contact Angles ◽  
Supramolecular Complex ◽  
Specific Interactions ◽  
Water Contact ◽  
Pyridine Complexes

Supramolecular complex of azobenzene carboxylic acid/pyridine functionalized benzoxazine system featured significantly lower curing temperatures and maintain high water contact angles.

scholarly journals 698 PB 306 WETTABILITY AND SURFACE TENSION OF FRUIT SURFACES

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 533a-533 ◽  
Author(s):  
L. Cisneros-Zevallos ◽  
M. E. Saltveit ◽  
J. M Krochta
Keyword(s):  
Surface Tension ◽  
Water Repellency ◽  
High Water ◽  
Contact Angles ◽  
Stone Fruits ◽  
Water Contact ◽  
Wetting Behavior ◽  
Apple Cultivars ◽  
Chemical Groups ◽  
Apple Fruits

Nettability is an important factor to be considered in postharvest treatments such as washing, aqueous dippings, coatings, etc. Pome fruits (ten apple and four pear cultivars) and stone fruits (nectarine and plums) were evaluated for wetting behavior and surface tension at room temperature. Nettability was assessed by measuring contact angles of water. Surface tension was calculated by measuring contact angles of methylene iodide and water or by a series of pure surfactants using Zisman's method. Wetting behavior on apple fruits depended on cultivar, with water contact angles ranging from 75° to 131°. For pear fruits, wetting also depended on cultivar. Calculated surface tensions of pear fruits were in general higher than most apple cultivars tested. In stone fruits, plums presented a high water-repellency with a contact angle of 137°. The wetting of fruit surfaces seems to be governed by the nature of the chemical groups exposed on the surface of the cuticle and also by the surface roughness, as evidenced by tire high values of some contact angles.

scholarly journals Three-Dimensional Soft Material Micropatterning via Grayscale Photolithography for Improved Hydrophobicity of Polydimethylsiloxane (PDMS)

Micromachines ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 78
Author(s):  
Intan Sue Liana Abdul Hamid ◽  
Beh Khi Khim ◽  
Mohammad Faiz Mohamed Omar ◽  
Khairu Anuar Mohamad Zain ◽  
Nuha Abd Rhaffor ◽  
...  
Keyword(s):  
Pure Water ◽  
Three Dimensional ◽  
Surface Hydrophobicity ◽  
Contact Angles ◽  
Master Mold ◽  
Water Contact ◽  
Pdms Surface ◽  
Lithography Technique ◽  
Scanning Electron ◽  
Micropillar Arrays

In this present work, we aim to improve the hydrophobicity of a polydimethylsiloxane (PDMS) surface. Various heights of 3D PDMS micropillars were fabricated via grayscale photolithography, and improved wettability was investigated. Two approaches of PDMS replication were demonstrated, both using a single master mold to obtain the micropillar arrays. The different heights of fabricated PDMS micropillars were characterized by scanning electron microscopy (SEM) and a surface profiler. The surface hydrophobicity was characterized by measuring the water contact angles. The fabrication of PDMS micropillar arrays was shown to be effective in modifying the contact angles of pure water droplets with the highest 157.3-degree water contact angle achieved by implementing a single mask grayscale lithography technique.

scholarly journals Influence of Anodizing Parameters on Surface Morphology and Surface-Free Energy of Al2O3 Layers Produced on EN AW-5251 Alloy

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 695 ◽  
Author(s):  
Marek Bara ◽  
Mateusz Niedźwiedź ◽  
Władysław Skoneczny
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Cross Sections ◽  
Contact Angles ◽  
Oxide Layers ◽  
X Ray ◽  
Energy Value ◽  
Average Value ◽  
Energetic State ◽  
Scanning Electron

The paper presents the influence of the surface anodizing parameters of the aluminum alloy EN AW-5251 on the physicochemical properties of the oxide layers produced on it. Micrographs of the surface of the oxide layers were taken using a scanning electron microscope (SEM). The chemical composition of cross-sections from the oxide layers was studied using energy dispersive spectroscopy (EDS). The phase structure of the Al2O3 layers was determined by the pattern method using X-ray diffractometry (XRD). The nanomorphology of the oxide layers were analyzed based on microscopic photographs using the ImageJ 1.50i program. The energetic state of the layers was based on the surface-free energy (SFE), calculated from measurements of contact angles using the Owens-Wendt method. The highest surface-free energy value (49.12 mJ/m2) was recorded for the sample produced at 293 K, 3 A/dm2, in 60 min. The lowest surface-free energy value (31.36 mJ/m2) was recorded for the sample produced at 283 K, 1 A/dm2, in 20 min (the only hydrophobic layer). The highest average value nanopore area (2358.7 nm2) was recorded for the sample produced at 303 K, 4 A/dm2, in 45 min. The lowest average value nanopore area (183 nm2) was recorded for the sample produced at 313 K, 1 A/dm2, in 20 min.

scholarly journals Environment-Friendly and Two-Component Method for Fabrication of Highly Hydrophobic Wood Using Poly(methylhydrogen)siloxane

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 124
Author(s):  
Jie Gao ◽  
Wensheng Lin ◽  
Shumin Lin ◽  
Xinxiang Zhang ◽  
Wenbin Yang ◽  
...  
Keyword(s):  
Cross Sections ◽  
Contact Angles ◽  
Practical Application ◽  
Water Contact ◽  
Water Separation ◽  
Environment Friendly ◽  
Two Component ◽  
Oil Water Separation ◽  
Oil Water ◽  
Highly Hydrophobic

Practical application of wood remains a great challenge because of its highly hydrophilic property. In this work, highly hydrophobic wood was produced using an environment-friendly and two-component package method. Poly(methylhydrogen)siloxane (PMHS) and inhibitor played the key role in the hydrophobicity of wood and the assembly process. The two-component package mechanism was discussed in detail. As a result, the water contact angles of the modified wood surface for the radial and cross sections were 139.5° and 152.9°, respectively, which provided the resultant wood high hydrophobicity and dimensional stability. The two-component package method afforded the wood good anti-fouling property and UV-resistance. In addition, the two-component package method could also be applied in functionalization of filter paper for oil/water separation.

scholarly journals Surface Characterization of Asymmetric Bi-Soft Segment Poly(ester urethane urea) Membranes for Blood-Oxygenation Medical Devices

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Mónica Faria ◽  
Vítor Geraldes ◽  
Maria Norberta de Pinho
Keyword(s):  
Cross Sections ◽  
Surface Characterization ◽  
Soft Segment ◽  
Surface Characteristics ◽  
Contact Angles ◽  
Sem Analysis ◽  
Blood Oxygenation ◽  
Water Contact ◽  
Streaming Potentials ◽  
Zeta Potentials

Asymmetric bi-soft segment poly(ester urethane urea) (PEUU) membranes containing polycaprolactone (PCL) as a second soft segment are synthesized with PCL-diol ranging from 0% to 15% (w/w). Bulk and surface characteristics of the PEUU membranes were investigated by scanning electron microscopy (SEM), static water contact angles, and surface streaming potentials and were correlated to hemocompatibility properties, namely, hemolysis and thrombosis degrees. SEM analysis reveals PEUU membranes with asymmetric cross-sections and top dense surfaces with distinct morphologies. The increase in PCL-diol content yields PEUU membranes with blood-contacting surfaces that are smoother, more hydrophilic, and with higher maximum zeta potentials. The results obtained in this work give no evidence of a correlation between hydrophilicity/zeta potentials and the hemolysis/thrombosis degree of blood-contacting surfaces of the PEUU membranes. In contrast, other hemocompatibility aspects reveal that the more hydrophilic membranes are associated with lower platelet deposition and inhibition of extreme states of platelet activation.

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