The Application of Starch - Sodium Alginate Composite Coating on Transparent Paper for Food Packaging

2014 ◽  
Vol 893 ◽  
pp. 472-477 ◽  
Author(s):  
Xuan Jiang ◽  
Gang Chen ◽  
Zhi Qiang Fang
Keyword(s):  
Contact Angle ◽  
Sodium Alginate ◽  
Food Packaging ◽  
Contact Angles ◽  
Barrier Property ◽  
Dynamic Changes ◽  
Coating Solution ◽  
Coated Papers ◽  
Base Paper ◽  
Coating Weight

Fluorocarbons were added into the mixture of modified starch and sodium alginate to get uniform coating solution, and the solution was then coated on the surface of transparent paper. The color as well as grease barrier property of paper at different coating weight were studied. The results showed that color under different coating weights were not significantly different from base paper. The scanning electron microscopy (SEM) diagram showed the surface of paper became smoother and more homogeneous as the coating weight increased. The grease barrier property of coated papers were significantly improved compared with base paper according to Tappi-559 kit test. A highest grease rating number of 12 was obtained when the coating weight became 3.3 g/m2. The dynamic changes in contact angle studies revealed that the contact angle of the base paper was continuously decreased from 29.41 °minutes to 23.46 °within 20, the contact angles of coated papers were significantly increased, and reaching a steady state within 2min with the maximum rate of contact angle change was of merely 0.06 ° / min.

Development of Grease Resistant Packaging Paper Using Cellulose Nanocrystals and Sodium Alginate

2020 ◽  
Vol 12 (2) ◽  
pp. 212-219 ◽  
Author(s):  
Chanyanutch Setajit ◽  
Chutima Kongvarhodom ◽  
Huining Xiao
Keyword(s):  
Mechanical Property ◽  
Sodium Alginate ◽  
Cellulose Nanocrystals ◽  
Paper Copy ◽  
Weight Ratio ◽  
Barrier Properties ◽  
Pure Cellulose ◽  
Coated Papers ◽  
Packaging Paper ◽  
Coating Weight

A biodegradable packaging paper with excellent grease resistance was produced using cellulose nanocrystals and sodium alginate. This study aims to reduce the porosity of paper by filling the pores with cellulose nanocrystals and using sodium alginate as a binder. Different types of papers, including filter paper, copy paper, and supercalendered paper, were used. Pure cellulose nanocrystals and cellulose nanocrystals/sodium alginate solutions at different concentrations and ratios (2:8, 5:5, and 9:1 by weight ratio) were applied to papers by coating and impregnation techniques. The resulting papers were then characterized with atomic force microscopy and scanning electron microscopy for the surface morphology. The grease barrier and the mechanical property were investigated in accordance with TAPPI standards. The results demonstrated that the copy paper coated with 2:8 of cellulose nanocrystals/sodium alginate showed excellent grease barrier properties. Within 48 h of the test period for grease to penetrate the coated paper, almost 100% of the grease barrier was achieved when the coating weight was set at 4 g/m2. The roughness of the paper surface significantly decreased, thereby resisting the penetration of oil from one side to another. Moreover, the mechanical property of both cellulose nanocrystals- and cellulose nanocrystals/sodium alginate-coated papers was improved due to the addition of cellulose nanocrystals as a reinforced filler.

scholarly journals Water and oil resistance improvement of paper coated with aqueous mixture of hydrophilic and hydrophobic cross-linked copolymers

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 3147-3160
Author(s):  
Zhaoping Song ◽  
Jiebin Tang ◽  
Huili Wang ◽  
Feixiang Guan ◽  
Yutao Wu ◽  
...  
Keyword(s):  
Contact Angle ◽  
Sodium Alginate ◽  
Filter Paper ◽  
Contact Angles ◽  
Hydrophobic Properties ◽  
Coated Paper ◽  
Water Contact ◽  
Oil Resistance ◽  
Aqueous Mixture ◽  
Resistance Improvement

An aqueous mixture of hydrophilic and hydrophobic cross-linked copolymers was prepared and coated on the surface of filter paper to improve the water and oil resistances. The mixture was mainly composed of sodium alginate and hydroxyl-terminated polydimethylsiloxane (PDMS)-tetramethoxysilane (TMOS) cross-linked network. The results indicated that the resistances to both water and oil of the resulting paper were significantly enhanced. The water contact angle results demonstrated that the mixture enhanced the hydrophobic properties of the coated paper greatly with water contact angles higher than 110°, and the coated paper showed excellent oil resistance with a Kit number as high as 10.

Influence of coating grammage on the utility properties of coated papers

2021 ◽  
Vol 113 ◽  
pp. 5-12
Author(s):  
Aleksandra Niska ◽  
Edyta Małachowska
Keyword(s):  
High Surface ◽  
Hydrophobic Surface ◽  
Strength Properties ◽  
Added Value ◽  
Paper Mills ◽  
Coated Papers ◽  
Base Paper ◽  
Increased Strength ◽  
Coating Weight ◽  
Mechanical Surface

Influence of coating grammage on the utility properties of coated papers.The paper coating offers the opportunity to create a product with high added value, the potential of which has been recognized by both paper mills and polygraphs.Indeed, paraffin coatings have excellent barrier, sliding and strength properties, and also increase the quality and durability of the print. This paper presents the results of the research on the influence of the coating weight on the functional properties of the coated paper. To this end, a commercially available paper was coated with a paraffin emulsionusing various Mayer rods and then tested using standard mechanical, surface, and water absorption tests. It was found that the coating of the base paper, regardless of the amount of the applied mixture, significantly influences its hydrophobic, surface, and strength properties. Papers with the highest coating weight allowed to obtain a paper with increased strength and high surface smoothing. The completed coatings significantly increased the water barrier, regardless of their thickness

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 Biomimetic Approach for the Elaboration of Highly Hydrophobic Surfaces: Study of the Links between Morphology and Wettability

Biomimetics ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 38
Author(s):  
Quentin Legrand ◽  
Stephane Benayoun ◽  
Stephane Valette
Keyword(s):  
Contact Angle ◽  
Ginkgo Biloba ◽  
Contact Angle Hysteresis ◽  
Contact Angles ◽  
Textured Surfaces ◽  
Replication Process ◽  
Wetting Behavior ◽  
Static Contact ◽  
Biomimetic Approach ◽  
Highly Hydrophobic

This investigation of morphology-wetting links was performed using a biomimetic approach. Three natural leaves’ surfaces were studied: two bamboo varieties and Ginkgo Biloba. Multiscale surface topographies were analyzed by SEM observations, FFT, and Gaussian filtering. A PDMS replicating protocol of natural surfaces was proposed in order to study the purely morphological contribution to wetting. High static contact angles, close to 135∘, were measured on PDMS replicated surfaces. Compared to flat PDMS, the increase in static contact angle due to purely morphological contribution was around 20∘. Such an increase in contact angle was obtained despite loss of the nanometric scale during the replication process. Moreover, a significant decrease of the hysteresis contact angle was measured on PDMS replicas. The value of the contact angle hysteresis moved from 40∘ for flat PDMS to less than 10∘ for textured replicated surfaces. The wetting behavior of multiscale textured surfaces was then studied in the frame of the Wenzel and Cassie–Baxter models. Whereas the classical laws made it possible to describe the wetting behavior of the ginkgo biloba replications, a hierarchical model was developed to depict the wetting behavior of both bamboo species.

scholarly journals Design of Sodium Alginate/Gelatin-Based Emulsion Film Fused with Polylactide Microparticles Charged with Plant Extract

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 745 ◽  
Author(s):  
Weronika Prus-Walendziak ◽  
Justyna Kozlowska
Keyword(s):  
Sodium Alginate ◽  
Plant Extract ◽  
Contact Angles ◽  
Polymeric Films ◽  
Solvent Evaporation Method ◽  
Calendula Officinalis ◽  
Flower Extract ◽  
Polymeric Microparticles ◽  
Emulsion Film ◽  
Emulsion Films

This study aimed at designing emulsion films based on sodium alginate, gelatin, and glycerol, and their modification by the addition of lipids (cottonseed oil and beeswax). Film composition with the most promising properties was further modified by the incorporation of polylactide (PLA) microparticles with Calendula officinalis flower extract. PLA microspheres were obtained by the emulsion/solvent evaporation method. The size distribution of oily particles in emulsions was investigated. Mechanical properties, moisture content, UV-Vis spectra, and the color of films were analyzed, while biophysical skin parameters were assessed after their application to the skin. Moreover, the contact angles were measured, and the surface free energy of polymeric films was determined. An investigation of the amount of Calendula officinalis flower extract which can be incorporated into PLA microparticles was performed. The modification of the composition of films significantly influenced their physicochemical properties. The selected active ingredient in the form of plant extract was successfully incorporated into polymeric microparticles that were further added into the developed emulsion film. The condition of the skin after the application of obtained emulsion films improved. The prepared materials, especially containing microparticles with plant extract, can be considered for designing new cosmetic forms, such as cosmetic masks, as well as new topical formulations for pharmaceutical delivery.

scholarly journals Is contact angle a cause or an effect? – A cautionary tale

2020 ◽  
Vol 146 ◽  
pp. 03004
Author(s):  
Douglas Ruth
Keyword(s):  
Contact Angle ◽  
Solid Surface ◽  
Contact Angles ◽  
Two Dimensions ◽  
Experimental Results ◽  
Flow In Porous Media ◽  
Two Dimensional ◽  
Wide Range ◽  
Fluid Drop ◽  
Surrounding Fluid

The most influential parameter on the behavior of two-component flow in porous media is “wettability”. When wettability is being characterized, the most frequently used parameter is the “contact angle”. When a fluid-drop is placed on a solid surface, in the presence of a second, surrounding fluid, the fluid-fluid surface contacts the solid-surface at an angle that is typically measured through the fluid-drop. If this angle is less than 90°, the fluid in the drop is said to “wet” the surface. If this angle is greater than 90°, the surrounding fluid is said to “wet” the surface. This definition is universally accepted and appears to be scientifically justifiable, at least for a static situation where the solid surface is horizontal. Recently, this concept has been extended to characterize wettability in non-static situations using high-resolution, two-dimensional digital images of multi-component systems. Using simple thought experiments and published experimental results, many of them decades old, it will be demonstrated that contact angles are not primary parameters – their values depend on many other parameters. Using these arguments, it will be demonstrated that contact angles are not the cause of wettability behavior but the effect of wettability behavior and other parameters. The result of this is that the contact angle cannot be used as a primary indicator of wettability except in very restricted situations. Furthermore, it will be demonstrated that even for the simple case of a capillary interface in a vertical tube, attempting to use simply a two-dimensional image to determine the contact angle can result in a wide range of measured values. This observation is consistent with some published experimental results. It follows that contact angles measured in two-dimensions cannot be trusted to provide accurate values and these values should not be used to characterize the wettability of the system.

scholarly journals Fabrication of elastic, conductive, wear-resistant superhydrophobic composite material

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Seyed Mehran Mirmohammadi ◽  
Sasha Hoshian ◽  
Ville P. Jokinen ◽  
Sami Franssila
Keyword(s):  
Contact Angle ◽  
Composite Material ◽  
Contact Angles ◽  
Wet Etching ◽  
Sliding Angle ◽  
Electrically Conductive ◽  
Wear Resistant ◽  
Nanoscale Structures ◽  
Mechanical Abrasion ◽  
Mechanical Durability

AbstractA polydimethylsiloxane (PDMS)/Cu superhydrophobic composite material is fabricated by wet etching, electroless plating, and polymer casting. The surface topography of the material emerges from hierarchical micro/nanoscale structures of etched aluminum, which are rigorously copied by plated copper. The resulting material is superhydrophobic (contact angle > 170°, sliding angle < 7° with 7 µL droplets), electrically conductive, elastic and wear resistant. The mechanical durability of both the superhydrophobicity and the metallic conductivity are the key advantages of this material. The material is robust against mechanical abrasion (1000 cycles): the contact angles were only marginally lowered, the sliding angles remained below 10°, and the material retained its superhydrophobicity. The resistivity varied from 0.7 × 10–5 Ωm (virgin) to 5 × 10–5 Ωm (1000 abrasion cycles) and 30 × 10–5 Ωm (3000 abrasion cycles). The material also underwent 10,000 cycles of stretching and bending, which led to only minor changes in superhydrophobicity and the resistivity remained below 90 × 10–5 Ωm.

The Surface Modification with Fluorocarbon Thin Films for the Prevention of Stiction in Mems

1998 ◽  
Vol 518 ◽  
Author(s):  
Sang-Ho Lee ◽  
Myong-Jong Kwon ◽  
Jin-Goo Park ◽  
Yong-Kweon Kim ◽  
Hyung-Jae Shin
Keyword(s):  
Contact Angle ◽  
Contact Angle Hysteresis ◽  
Contact Angles ◽  
Fluorocarbon Films ◽  
Perfluorodecanoic Acid ◽  
Large Hysteresis ◽  
Static Contact ◽  
Receding Contact ◽  
Highly Hydrophobic ◽  
Receding Contact Angle

AbstractHighly hydrophobic fluorocarbon films were prepared by the vapor phase (VP) deposition method in a vacuum chamber using both liquid (3M's FC40, FC722) and solid sources (perfluorodecanoic acid (CF3(CF2)8COOH), perfluorododecane (C12F26)) on Al, Si and oxide coated wafers. The highest static contact angles of water were measured on films deposited on aluminum substrate. But relatively lower contact angles were obtained on the films on Si and oxide wafers. The advancing and receding contact angle analysis using a captive drop method showed a large contact angle hysteresis (ΔH) on the VP deposited fluorocarbon films. AFM study showed poor film coverage on the surface with large hysteresis. FTIR-ATR analysis positively revealed the stretching band of CF2 groups on the VP deposited substrates. The thermal stability of films was measured at 150°C in air and nitrogen atmospheres as a function of time. The rapid decrease of contact angles was observed on VP deposited FC and PFDA films in air. However, no decrease of contact angle on them was observed in N2.

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