scholarly journals Active Barrier Coating for Packaging Paper with Controlled Release of Sunflower Oils

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3561
Author(s):  
Pieter Samyn
Keyword(s):  
Controlled Release ◽  
Surface Composition ◽  
Barrier Properties ◽  
Organic Coating ◽  
Contact Angles ◽  
Water Contact ◽  
Chemical Surface ◽  
Oil Resistance ◽  
Thermal Release ◽  
Sunflower Oils

The use of paper as a sustainable packaging material is favored, but it lacks sufficient barrier properties in terms of water repellence and oil resistance. Novel approaches consider active packaging materials or coatings with controlled release providing additional functionality for delivery of specific components to the surface. In this study, the development of a waterborne coating with organic nanoparticles and encapsulated sunflower oils is presented as a system for thermal release of the oil and on-demand tuning of the final barrier properties of the paper substrate. After synthesis of the nanoparticles, it seems that the encapsulation of various grades of sunflower oil (i.e., either poly-unsaturated or mono-unsaturated) strongly affects the encapsulation efficiency and thermal release profiles. The water contact angles are controlled by the oil release and chemical surface composition of the coating upon thermal heating. The oil resistance of the paper improves as a more continuous oil film is formed during thermal release. In particular, the chemical surface composition of the paper coatings is detailed by means of micro-Raman spectroscopy and surface imaging, which provide an analytical quantification tool to evaluate surface coverage, oil delivery, and variations in organic coating moieties.

The Use of X-Ray Photoelectron Spectroscopy for the Study of Oral Streptococcal Cell Surfaces

1997 ◽  
Vol 11 (4) ◽  
pp. 388-394 ◽  
Author(s):  
H.C. Van Der Mei ◽  
H.J. Busscher
Keyword(s):  
Cell Surface ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Contact Angles ◽  
Microbial Cell ◽  
Cell Surfaces ◽  
Water Contact ◽  
X Ray

Physicochemical and structural properties of microbial cell surfaces play an important role in their adhesion to surfaces and are determined by the chemical composition of the outermost cell surface. Many traditional methods used to determine microbial cell wall composition require fractionation of the organisms and consequently do not yield information about the composition of the outermost cell surface. X-ray photoelectron spectroscopy (XPS) measures the elemental composition of the outermost cell surfaces of micro-organisms. The technique requires freeze-drying of the organisms, but, nevertheless, elemental surface concentration ratios of oral streptococcal cell surfaces with peritrichously arranged surface structures showed good relationships with physicochemical properties measured under physiological conditions, such as zeta potentials. Isoelectric points ap-peared to be governed by the relative abundance of oxygen- and nitrogen-containing groups on the cell surfaces. Also, the intrinsic microbial cell-surface hydrophobicity by water contact angles related to the cell-surface composition as by XPS and was highest for strains with an elevated isoelectric point. Inclusion of elemental surface compositions for tufted streptococcal strains caused deterioration of the relationships found. Interestingly, hierarchical cluster analysis on the basis of the elemental surface compositions revealed that, of 36 different streptococcal strains, only four S. rattus as well as nine S. mitis strains were located in distinct groups, well separated from the other streptococcal strains, which were all more or less mixed in one group.

scholarly journals Surface Modification of Additively Manufactured Nitinol by Wet Chemical Etching

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7683
Author(s):  
Denis Nazarov ◽  
Aida Rudakova ◽  
Evgenii Borisov ◽  
Anatoliy Popovich
Keyword(s):  
Mechanical Properties ◽  
Free Surface ◽  
Surface Energy ◽  
Surface Composition ◽  
Three Dimensional ◽  
Physicochemical Characteristics ◽  
Contact Angles ◽  
Free Surface Energy ◽  
Flat Plates ◽  
Water Contact

Three-dimensional printed nitinol (NiTi) alloys have broad prospects for application in medicine due to their unique mechanical properties (shape memory effect and superplasticity) and the possibilities of additive technologies. However, in addition to mechanical properties, specific physicochemical characteristics of the surface are necessary for successful medical applications. In this work, a comparative study of additively manufactured (AM) NiTi samples etched in H2SO4/H2O2, HCl/H2SO4, and NH4OH/H2O2 mixtures was performed. The morphology, topography, wettability, free surface energy, and chemical composition of the surface were studied in detail. It was found that etching in H2SO4/H2O2 practically does not change the surface morphology, while HCl/H2SO4 treatment leads to the formation of a developed morphology and topography. In addition, exposure of nitinol to H2SO4/H2O2 and HCl/H2SO4 contaminated its surface with sulfur and made the surface wettability unstable in air. Etching in NH4OH/H2O2 results in surface cracking and formation of flat plates (10–20 microns) due to the dissolution of titanium, but clearly increases the hydrophilicity of the surface (values of water contact angles are 32–58°). The etch duration (30 min or 120 min) significantly affects the morphology, topography, wettability and free surface energy for the HCl/H2SO4 and NH4OH/H2O2 etched samples, but has almost no effect on surface composition.

The Wetting of Insect Cuticles by Water

1955 ◽  
Vol 32 (3) ◽  
pp. 591-617 ◽  
Author(s):  
M. W. HOLDGATE
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Surface Properties ◽  
Surface Composition ◽  
Contact Angles ◽  
Aquatic Species ◽  
Water Contact ◽  
Calliphora Erythrocephala ◽  
Wetting Properties ◽  
Wide Range

1. The water contact angles of insects show a wide range of variation, which is broadly correlated with surface roughness and with habitat. 2. The contact angles of species inhabiting stored products or carrion are greatly modified by contamination. This produces large variations between apparently similar individuals. 3. In terrestrial insects surface roughness increases the contact angles to very large apparent values. Detailed analyses of its effect have been made in the pupa of Tenebrio molitor and the adult Calliphora erythrocephala. In some aquatic insects surface roughness leads to a reduction in the contact angles; this has been studied in the nymph of Anax imperator. 4. Prolonged immersion in water causes a lowering of the contact angles of all the insects examined, and the low angles of many aquatic species may therefore be the direct effect of their environment. In some aquatic species there is evidence of the active maintenance of a large contact angle during life. 5. Changes in contact angle accompany processes of cuticle secretion and will occur at any moult if changes in roughness or habitat take place. 6. The observed variations of surface properties can be explained without assuming any variation in the chemical composition of the cuticle surface. Wetting properties are of little value as indicators of cuticle surface composition. 7. The biological aspects of insect surface properties are briefly discussed.

scholarly journals Improvement of Paper Resistance against Moisture and Oil by Coating with Poly(-3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and Polycaprolactone (PCL)

2021 ◽  
Vol 11 (17) ◽  
pp. 8058
Author(s):  
Emanuela Lo Faro ◽  
Camilla Menozzi ◽  
Fabio Licciardello ◽  
Patrizia Fava
Keyword(s):  
Barrier Properties ◽  
Surface Hydrophobicity ◽  
Contact Angles ◽  
Future Research ◽  
Water Contact ◽  
Contact Materials ◽  
Paper Coatings ◽  
Angle Measurements ◽  
Oil Resources ◽  
Plain Paper

Surface hydrophobicity and grease resistance of paper may be achieved by the application of coatings usually derived from fossil-oil resources. However, poor recyclability and environmental concerns on generated waste has increased interest in the study of alternative paper coatings. This work focuses on the study of the performances offered by two different biopolymers, poly(3-hydroxybutyrate-co-3hydroxyvalerate) (PHBV) and polycaprolactone (PCL), also assessing the effect of a plasticizer (PEG) when used as paper coatings. The coated samples were characterized for the structural (by scanning electron microscopy, SEM), diffusive (water vapor and grease barrier properties), and surface properties (affinity for water and oil, by contact angle measurements). Samples of polyethylene-coated and fluorinated paper were used as commercial reference. WVTR of coated samples generally decreased and PHBV and PCL coatings with PEG at 20% showed interesting low wettability, as inferred from the water contact angles. Samples coated with PCL also showed increased grease resistance in comparison with plain paper. This work, within the limits of its lab-scale, offers interesting insights for future research lines toward the development of cellulose-based food contact materials that are fully recyclable and compostable.

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.

scholarly journals Siloxane-Starch-Based Hydrophobic Coating for Multiple Recyclable Cellulosic Materials

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4977
Author(s):  
Tomasz Ganicz ◽  
Krystyna Rózga-Wijas
Keyword(s):  
High Surface ◽  
Barrier Properties ◽  
Surface Hydrophobicity ◽  
Contact Angles ◽  
Recycling Process ◽  
Water Contact ◽  
Cellulosic Materials ◽  
Circulating Water ◽  
Hydrophobic Coating ◽  
Aqueous Mixture

The results of the application of a new hydrophobization agent based on a triethoxymethylsilane and standard starch aqueous mixture for mass-produced cellulosic materials—printing paper, paperboard, and sack paper—have been evaluated to examine whether such a mixture can be used in industrial practice. The application of this agent on laboratory sheets prepared in a repetitive recycling process was performed to investigate its influence on the formation and properties of the products, as well as the contamination of circulating water. Measurements of the water contact angle, Cobb tests, and water penetration dynamics (PDA) were performed to test the barrier properties of the resulting materials. The effects of the applied coatings and recycling process on the paper’s tensile strength, tear index, roughness, air permeance, and ISO brightness were studied. Studies have proven that this formulation imparts relatively high surface hydrophobicity to all materials tested (contact angles above 100°) and a significant improvement in barrier properties while maintaining good mechanical and optical performance. The agent also does not interfere with the pulping and re-forming processes during recycling and increases circulation water contamination to an acceptable degree. Attenuated total reflectance Fourier-transform infrared (FT-IR) spectra of the paper samples revealed the presence of a polysiloxane network on the surface.

Cluster analysis of genotypically characterized Lactobacillus species based on physicochemical cell surface properties and their relationship with adhesion to hexadecane

1997 ◽  
Vol 43 (3) ◽  
pp. 284-291 ◽  
Author(s):  
Kevin W. Millsap ◽  
Gregor Reid ◽  
Henny C. van der Mei ◽  
Henk J. Busscher
Keyword(s):  
Cluster Analysis ◽  
Cell Surface ◽  
Surface Properties ◽  
Surface Composition ◽  
Contact Angles ◽  
The Other ◽  
Lactobacillus Species ◽  
Water Contact ◽  
Cell Surface Properties ◽  
Isoelectric Points

Lactobacilli can interfere with the adhesion of uropathogens to uroepithelial cells and catheter materials through a variety of mechanisms, such as adhesion. Lactobacillus adhesion to substratum surfaces has been theorized to result from the physicochemical properties of the interacting surfaces. In this paper physicochemical cell-surface properties, including hydrophobicity (determined by water contact angles), pH dependence of zeta potentials, elemental surface composition (determined by X-ray photoelectron spectroscopy), and adhesion to hexadecane, of four genotypically characterized Lactobacillus species (eight L. acidophilus, eight L. casei, four L. fermentum, and seven L. plantarum strains) were determined to see whether a grouping of the strains according to their phenotypes could be obtained that corresponded with the genotypic characterization of the strains. The strains showed major differences in physicochemical cell-surface properties: at the species level relationships could be observed between water contact angles, isoelectric points, and the N/C and O/C elemental surface concentration ratios, with nitrogen-containing groups (proteins) being responsible for increased hydrophobicities and isoelectric points, and oxygen-containing groups (phosphates and polysaccharides) yielding decreased hydrophobicities and isoelectric points. A hierarchical cluster analysis grouped all L. acidophilus strains in one well-separated cluster that also included two L. casei and two L. fermentum strains. Separation of L. acidophilus from the other species was done predominantly on the basis of increased cell surface hydrophobicity (average water contact angle of 63°) and isoelectric point (approximately pH 3.3) as compared with the other species, which had lower water contact angles and isoelectric points, and corresponded with the observation that only L. acidophilus strains adhered in measurable numbers to hexadecane. Also, the L. plantarum strains were grouped closely together in one cluster, but this cluster was heterogeneous due to the inclusion of L. casei and L. fermentum strains.Key words: Lactobacillus, surface properties, hydrophobicity, zeta potential, adhesion.

scholarly journals The Effect of Hydroxyl on the Superhydrophobicity of Dodecyl Methacrylate (LMA) Coated Fabrics through Simple Dipping-Plasma Crosslinked Method

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1263
Author(s):  
Liyun Xu ◽  
Yu Zhang ◽  
Ying Guo ◽  
Ruiyun Zhang ◽  
Jianjun Shi ◽  
...  
Keyword(s):  
Thermoplastic Polyurethane ◽  
Hydrophobic Effect ◽  
Surface Hydrophobicity ◽  
Contact Angles ◽  
Binding Property ◽  
Interesting Phenomenon ◽  
Water Contact ◽  
Capacitively Coupled ◽  
Pet Fabric ◽  
Dodecyl Methacrylate

In order to obtain stable superhydrophobicity, suitable hydrophobic treatment agents should be selected according to different material properties. In this paper, cotton and poly(ethylene terephthalate) (PET) fabrics were respectively coated with dodecyl methacrylate (LMA) via argon combined capacitively coupled plasma (CCP), and the surface hydrophobicity and durability of the treated cotton and polyester fabrics are also discussed. An interesting phenomenon happened, whereby the LMA-coated cotton fabric (Cotton-g-LMA) had better water repelling and mechanical durability properties than LMA-coated PET fabric (PET-g-LMA), and LMA-coated hydroxyl-grafted PET fabrics (PET fabrics were successively coated with polyethylene glycol (PEG) and LMA, PET-g-PEG & LMA) had a similar performance to cotton fabrics. The water contact angles of Cotton-g-LMA, PET-g-LMA and PET-g-PEG & LMA were 156°, 153° and 155°, respectively, and after 45 washing cycles or 1000 rubbing cycles, the corresponding water contact angles decreased to 145°, 88°, 134° and 146°, 127° and 143°, respectively. Additionally, thermoplastic polyurethane (TPU) and polyamides-6 (PA6) fabrics all exhibited the same properties as the PET fabric. Therefore, the grafting of hydroxyl can improve the hydrophobic effect of LMA coating and the binding property between LMA and fabrics effectively, without changing the wearing comfort.

scholarly journals Polypropylene/Lignin/POSS Nanocomposites: Thermal and Wettability Properties, Application in Water Remediation

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3950
Author(s):  
Abeer Alassod ◽  
Syed Rashedul Islam ◽  
Mina Shahriari Khalaji ◽  
Rogers Tusiime ◽  
Wanzhen Huang ◽  
...  
Keyword(s):  
Organic Liquid ◽  
Contact Angles ◽  
Water Remediation ◽  
Scanning Calorimetry ◽  
Water Contact ◽  
Thermally Induced ◽  
Dsc Measurements ◽  
Infrared Measurement ◽  
Oligomeric Silsesquioxane ◽  
Tga And Dsc

Compositing is an interesting strategy that has always been employed to introduce or enhance desired functionalities in material systems. In this paper, sponges containing polypropylene, lignin, and octavinyl-polyhedral oligomeric silsesquioxane (OV-POSS) were successfully prepared via an easy and elegant strategy called thermally induced phase separation (TIPS). To fully explore the behaviour of different components of prepared sponges, properties were characterized by a thermogravimetric analyser (TGA), differential scanning calorimetry (DSC), Fourier transform infrared measurement (FTIR), and scanning electron microscopy (SEM). Furthermore, wettability properties toward an organic liquid and oil were investigated. The FTIR analysis confirmed the chemical modification of the components. TGA and DSC measurements revealed thermal stability was much better with an increase in OV-POSS content. OV-POSS modified sponges exhibited ultra-hydrophobicity and high oleophilicity with water contact angles of more than 125°. The SEM revealed that POSS molecules acted as a support for reduced surface roughness. Moreover, OV-POSS-based blend sponges showed higher sorption capacities compared with other blend sponges without OV-POSS. The new blend sponges demonstrated a potential for use as sorbent engineering materials in water remediation.

scholarly journals Physico-Chemical Characterization and Antimicrobial Properties of Hybrid Film Based on Saponite and Phloxine B

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 325
Author(s):  
Nitin Chandra teja Dadi ◽  
Matúš Dohál ◽  
Veronika Medvecká ◽  
Juraj Bujdák ◽  
Kamila Koči ◽  
...  
Keyword(s):  
Hybrid Film ◽  
Antimicrobial Properties ◽  
Chemical Characterization ◽  
Layered Silicate ◽  
Contact Angles ◽  
Exchange Capacity ◽  
Resistant Bacteria ◽  
Hybrid Films ◽  
Water Contact ◽  
Physico Chemical

This research was aimed at the preparation of a hybrid film based on a layered silicate saponite (Sap) with the immobilized photosensitizer phloxine B (PhB). Sap was selected because of its high cation exchange capacity, ability to exfoliate into nanolayers, and to modify different surfaces. The X-ray diffraction of the films confirmed the intercalation of both the surfactant and PhB molecules in the Sap film. The photosensitizer retained its photoactivity in the hybrid films, as shown by fluorescence spectra measurements. The water contact angles and the measurement of surface free energy demonstrated the hydrophilic nature of the hybrid films. Antimicrobial effectiveness, assessed by the photodynamic inactivation on hybrid films, was tested against a standard strain and against methicillin-resistant bacteria of Staphylococcus aureus (MRSA). One group of samples was irradiated (green LED light; 2.5 h) and compared to nonirradiated ones. S. aureus strains manifested a reduction in growth from 1-log10 to over 3-log10 compared to the control samples with Sap only, and defects in S. aureus cells were proven by scanning electron microscopy. The results proved the optimal photo-physical properties and anti-MRSA potential of this newly designed hybrid system that reflects recent progress in the modification of surfaces for various medical applications.

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