scholarly journals Surfactant-Induced Reconfiguration of Urea-Formaldehyde Resins Enables Improved Surface Properties and Gluability of Bamboo

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3542
Author(s):  
Lulu Liang ◽  
Yu Zheng ◽  
Yitian Wu ◽  
Jin Yang ◽  
Jiajie Wang ◽  
...  
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Surface Properties ◽  
High Efficiency ◽  
Urea Formaldehyde ◽  
Production Costs ◽  
Spreading Area ◽  
Uf Resin ◽  
Development And Utilization ◽  
Application Fields

The high-efficiency development and utilization of bamboo resources can greatly alleviate the current shortage of wood and promote the neutralization of CO2. However, the wide application of bamboo-derived products is largely limited by their unideal surface properties with adhesive as well as poor gluability. Herein, a facile strategy using the surfactant-induced reconfiguration of urea-formaldehyde (UF) resins was proposed to enhance the interface with bamboo and significantly improve its gluability. Specifically, through the coupling of a variety of surfactants, the viscosity and surface tension of the UF resins were properly regulated. Therefore, the resultant surfactant reconfigured UF resin showed much-improved wettability and spreading performance to the surface of both bamboo green and bamboo yellow. Specifically, the contact angle (CA) values of the bamboo green and bamboo yellow decreased from 79.6° to 30.5° and from 57.5° to 28.2°, respectively, with the corresponding resin spreading area increasing from 0.2 mm2 to 7.6 mm2 and from 0.1 mm2 to 5.6 mm2. Moreover, our reconfigured UF resin can reduce the amount of glue spread applied to bond the laminated commercial bamboo veneer products to 60 g m−2, while the products prepared by the initial UF resin are unable to meet the requirements of the test standard, suggesting that this facile method is an effective way to decrease the application of petroleum-based resins and production costs. More broadly, this surfactant reconfigured strategy can also be performed to regulate the wettability between UF resin and other materials (such as polypropylene board and tinplate), expanding the application fields of UF resin.

Increasing Storage Modulus, Contact Angle and Surface Tension of Airway Mucus Increases Clearance by Simulated Cough Through a Model Trachea

2010 ◽  
Author(s):  
Anpalaki J. Ragavan ◽  
Cahit A. Evrensel ◽  
Peter Krumpe
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Storage Modulus ◽  
Surface Properties ◽  
Respiratory Diseases ◽  
Interactive Effects ◽  
Altered Surface ◽  
Human Trachea ◽  
Tension Increase ◽  
And Storage

Altered surface and viscoelastic material properties of mucus during respiratory diseases have a strong influence on its clearance by cilia and cough. Combined effects of the surface properties (contact angle and surface tension) and storage modulus with relatively unchanged viscosity on displacement of the simulated mucus aliquot during simulated cough through a model adult human trachea is investigated. For the mucus simulants used in this study contact angle and surface tension increase significantly as storage modulus increase while viscosity remains practically unchanged. Displacement of mucus simulant aliquots increased significantly with increasing storage modulus (and contact angle) at a given cough velocity in the range between 5 meters/second (m/s) and 30 m/s with duration 0.3 s. Results suggest that the interactive effects of elasticity and surface properties may help facilitate mucus displacement at low cough velocities.

scholarly journals Effect of Adjuvants and pH Adjuster on the Efficacy of Sulcotrione Herbicide

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 530 ◽  
Author(s):  
Łukasz Sobiech ◽  
Monika Grzanka ◽  
Grzegorz Skrzypczak ◽  
Robert Idziak ◽  
Sylwia Włodarczak ◽  
...  
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Shear Viscosity ◽  
Rapeseed Oil ◽  
High Efficiency ◽  
Low Ph ◽  
Reduced Dose ◽  
Spray Droplets ◽  
Liquid Spray ◽  
Negative Effect

The effectiveness of herbicides is affected by the pH of the spray liquid. The use of adjuvants can mitigate the negative effect of pH, and it also allows for a reduction in herbicide doses while maintaining high efficiency. Greenhouse studies were performed to evaluate the efficacy of the herbicide sulcotrione (HRAC F2), against barnyardgrass, at full or reduced doses with adjuvants, and a modified pH of the solutions. The contact angle and surface tension of liquid spray drops, as well as the shear viscosity of individual solutions, were also tested. Results indicated that at a low pH of the spray liquid (4), the use of a reduced dose of sulcotrione with adjuvant based on methylated rapeseed oil can increase the effectiveness of barnyardgrass control to the same level as at the full dose of herbicide. The use of adjuvants contributed to the reduction in the contact angle and the surface tension of liquid spray droplets. No significant differences in shear viscosity were observed for individual solutions.

Surface Properties of Molten Bismuth-Bismuth Chloride in Contact with Uranium Dioxide

1961 ◽  
Vol 14 (3) ◽  
pp. 409 ◽  
Author(s):  
DH Bradhurst ◽  
AS Buchanan
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Surface Properties ◽  
Uranium Dioxide ◽  
Surface Active Agent ◽  
Active Agent ◽  
Effective Surface ◽  
Liquid Bismuth ◽  
Surface Active ◽  
Bismuth Chloride

The wetting of uranium dioxide by liquid bismuth has been investigated by means of measurements of surface tension of the liquid and contact angle of the liquid on the solid. Bismuth chloride in low concentration was found to be a very effective surface active agent in improving the wetting of the solid by the metal.

Herbicidal Ionic Liquids with 2,4-D

Weed Science ◽  
2012 ◽  
Vol 60 (2) ◽  
pp. 189-192 ◽  
Author(s):  
Tadeusz Praczyk ◽  
Przemysław Kardasz ◽  
Ewa Jakubiak ◽  
Anna Syguda ◽  
Katarzyna Materna ◽  
...  
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Ionic Liquids ◽  
Winter Wheat ◽  
Surface Properties ◽  
Field Conditions

Three herbicidal ionic liquids (HILs)—alkyldi(2-hydroxyethyl)methylammonium (2,4-dichlorophenoxy)acetate, dialkyldimethylammonium (2,4-dichlorophenoxy)acetate, and alkyltrimethylammonium (2,4-dichlorophenoxy)acetate—were synthesized and their activity against broad-leaved weeds was investigated under field conditions. HILs as [cation][2,4-D] used in winter wheat were much more active compared to 2,4-D-dimethylammonium salt and demonstrated efficacy similar to 2,4-D 2-ethylhexyl ester. HILs exhibited desirable surface properties such as low contact angle of droplets and low surface tension. Moreover, the HILs may be safer to operators and neighboring plants due to their nonvolatile nature. HILs at 450 g ha−1 of 2,4-D did not injure wheat.

Assessment of Surface Properties of Silica-Bacterial Cell Complex: A Potential Application for Silicate Bioflotation Processes

2015 ◽  
Vol 1130 ◽  
pp. 515-518
Author(s):  
Edy Sanwani ◽  
Tri Wahyuningsih ◽  
Siti Khodijah Chaerun
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Surface Properties ◽  
Potential Application ◽  
Bacillus Pumilus ◽  
Binding Capacity ◽  
Hydrophobic Property ◽  
Water Contact ◽  
Cell Complexes ◽  
Silica Cell

The objective of the present work was to assess the surface properties of silica-cell complexes formed by Bacillus pumilus strain SKC-2 for bioflotation purposes. This bacterial strain was employed in this study because it is a Gram-positive, mixotrophic bacterium whose metal binding capacity extends to many different metals and circumstances as well as a biosurfactant producer. The strain was found to promote the formation of silica-cell complexes due to the generation of surface-active agents (i.e., extracellular polymeric substrances (EPS)) as represented by scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (SEM-EDS) observation. Surface properties of the complexes was assessed by water contact angle and surface tension measurements, demonstrating that bacterial cells reduced the surface tension of the solutions and increased the contact angle of the silica surfaces, representing a larger hydrophobic property. Therefore, the findings of this study provide clear evidence for the potential application of the bacterium Bacillus pumilus strain SKC-2 for silicate bioflotation processes (i.e., as frother and collector).

scholarly journals Calcium carbonate modified urea–formaldehyde resin adhesive for strength enhanced medium density fiberboard production

RSC Advances ◽  
2021 ◽  
Vol 11 (40) ◽  
pp. 25010-25017
Author(s):  
Li Lu ◽  
Yan Wang ◽  
Tianhua Li ◽  
Supeng Wang ◽  
Shoulu Yang ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Urea Formaldehyde ◽  
Medium Density Fiberboard ◽  
Urea Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Medium Density ◽  
Ionic Bond ◽  
Resin Adhesive ◽  
Uf Resin ◽  
Modified Urea

Reactions between CaCO3 and CH2O2 during polycondensation of UF resin produce Ca2+. Ionic bond complexation binds Ca2+ with UF resin. The UF resin crystalline percentage decreases from 26.86% to 22.71%. IB strength of resin bonded fiberboard increases from 0.75 to 0.94 MPa.

scholarly journals Influence of moisture content on the contact angle and surface tension measured on birch wood surfaces

2021 ◽  
Author(s):  
Rami Benkreif ◽  
Fatima Zohra Brahmia ◽  
Csilla Csiha
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Moisture Content ◽  
Solid Wood ◽  
Contact Angles ◽  
Surface Moisture ◽  
Wood Coatings ◽  
The Relationship ◽  
Wood Surfaces

AbstractSurface tension of solid wood surfaces affects the wettability and thus the adhesion of various adhesives and wood coatings. By measuring the contact angle of the wood, the surface tension can be calculated based on the Young-Dupré equation. Several publications have reported on contact angle measured with different test liquids, under different conditions. Results can only be compared if the test conditions are similar. While the roles of the drop volume, image shooting time etc., are widely recognized, the role of the wood surface moisture content (MC) is not evaluated in detail. In this study, the effect of wood moisture content on contact angle values, measured with distilled water and diiodomethane, on sanded birch (Betula pendula) surfaces was investigated, in order to find the relationship between them. With increasing MC from approximately 6% to 30%, increasing contact angle (decreasing surface tension) values were measured according to a logarithmic function. The function makes possible the calculation of contact angles that correspond to different MCs.

scholarly journals Effect of Optical and Morphological Control of Single-Structured LEC Device

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 843
Author(s):  
Woo Jin Jeong ◽  
Jong Ik Lee ◽  
Hee Jung Kwak ◽  
Jae Min Jeon ◽  
Dong Yeol Shin ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Surface Roughness ◽  
Surface Properties ◽  
High Efficiency ◽  
High Surface ◽  
Reduction Rate ◽  
Operating Characteristics ◽  
Emission Layer ◽  
Light Emitting ◽  
Stable Operating

We investigated the performance of single-structured light-emitting electrochemical cell (LEC) devices with Ru(bpy)3(PF6)2 polymer composite as an emission layer by controlling thickness and heat treatment. When the thickness was smaller than 120–150 nm, the device performance decreased because of the low optical properties and non-dense surface properties. On the other hand, when the thickness was over than 150 nm, the device had too high surface roughness, resulting in high-efficiency roll-off and poor device stability. With 150 nm thickness, the absorbance increased, and the surface roughness was low and dense, resulting in increased device characteristics and better stability. The heat treatment effect further improved the surface properties, thus improving the device characteristics. In particular, the external quantum efficiency (EQE) reduction rate was shallow at 100 °C, which indicates that the LEC device has stable operating characteristics. The LEC device exhibited a maximum luminance of 3532 cd/m2 and an EQE of 1.14% under 150 nm thickness and 100 °C heat treatment.

scholarly journals Eco-Friendly, High-Density Fiberboards Bonded with Urea-Formaldehyde and Ammonium Lignosulfonate

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 220
Author(s):  
Petar Antov ◽  
Viktor Savov ◽  
Ľuboš Krišťák ◽  
Roman Réh ◽  
George I. Mantanis
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
High Density ◽  
Thickness Swelling ◽  
Formaldehyde Content ◽  
Uf Resin ◽  
Natural Wood ◽  
European Standards

The potential of producing eco-friendly, formaldehyde-free, high-density fiberboard (HDF) panels from hardwood fibers bonded with urea-formaldehyde (UF) resin and a novel ammonium lignosulfonate (ALS) is investigated in this paper. HDF panels were fabricated in the laboratory by applying a very low UF gluing factor (3%) and ALS content varying from 6% to 10% (based on the dry fibers). The physical and mechanical properties of the fiberboards, such as water absorption (WA), thickness swelling (TS), modulus of elasticity (MOE), bending strength (MOR), internal bond strength (IB), as well as formaldehyde content, were determined in accordance with the corresponding European standards. Overall, the HDF panels exhibited very satisfactory physical and mechanical properties, fully complying with the standard requirements of HDF for use in load-bearing applications in humid conditions. Markedly, the formaldehyde content of the laboratory fabricated panels was extremely low, ranging between 0.7–1.0 mg/100 g, which is, in fact, equivalent to the formaldehyde release of natural wood.

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