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Non-Newtonian viscous fluids such as yogurt, honey, etc., due to their extremely high viscosity and complex fluidity, remain on food containers after use, where adhesion and staining occurs, which is a great inconvenience and causes a lot of wasted resources. Hydrophobic coatings can be an excellent candidate for eliminating liquid waste. Inexpensive wollastonite nanoparticles were used to build rough micro- and nano-structures, and chitosan was used to emulsify rice bran wax to prepare green and low surface energy emulsions. The above two were mechanically mixed to obtain the hydrophobic emulsion, and coated on the paper surface and heat-treated to prepare the hydrophobic paper. Contact angles up to 157.3°. The coating exhibits good self-cleaning properties for a wide range of non-Newtonian viscous food liquids and shows excellent resistance to repeated machine bending and multiple abrasion damages, while maintaining its hydrophobicity. After 40 cycles of friction, the contact angle is 148.1°, which is still close to 150° and has good hydrophobicity. In addition, the coating has great potential for application to the interior surfaces of various food packages to reduce or even eliminate liquid food residues. [ABSTRACT FROM AUTHOR]

Despite previous efforts, the fabrication of superhydrophobic substrate via an environment friendly and easy approach remains a great challenge. In this study, a low cost, simple, and green procedure was developed to prepare a superhydrophobic paper surface that is acceptable for the papermaking industry. First, a wax mixture (beeswax & carnauba wax) was emulsified and coated on the filter paper surface. Then, the coated paper was annealed at different temperatures. The further heat-treatmentrendered wax-coated paper hydrophobic or superhydrophobic because submicrometer or micrometer wax structures were present on the paper surface. The water contact angle of the annealed filter paper sample reached 151.5° at 60 °C, and the sliding angle was under 10°. Further, the relationship between surface composition and the hydrophobic properties of the coated paper samples was discussed. The obtained paper samples showed great potential in water/oil separation, as they had an efficiency over 99%. This work proposed a new simple and mild approach to fabricate superhydrophobic filter papers and explored the hydrophobicity and water/oil separation properties. [ABSTRACT FROM AUTHOR]

This research aimed to compare the effect of postmanufacture thermal treatment and wax emulsion (1%) as an additive on water absorption, thickness swelling, and formaldehyde emission of particleboard produced from Ficus retusa branchwood. The particleboards were single layer produced with a target density of 690 kg. m-3 and 12% urea formaldehyde as a binder. Three different temperatures (180, 200, and 220°C) and two different heat exposure durations (5 and 10 minutes) were applied. The statistical tests revealed that the post-manufacture heat treatments of the Ficus particleboard at 200°C/10 min and 230°C/5 and 10 min were effective in improving the dimensional stability (water absorption and thickness swelling) of the panels and reducing the formaldehyde emission. Additionally, using the 1% wax emulsion in the panels enhanced the dimensional stability and was comparable with the 220°C/10 min treatment, while it had no significant effect on the formaldehyde emission. Moreover, the F. retusa branchwood was suitable for particleboard production using the production parameters introduced in this study. [ABSTRACT FROM AUTHOR]

For the first time, efficiency of the carnauba wax-nanoclay emulsions in preserving postharvest quality of ‘Valencia’ fruit was evaluated upon simulated storage and marketing. The different coatings containing nanoclay (i.e., 0.0, 0.5 and 1.0 w%) applied on orange and their performance were compared with uncoated fruit and two different commercial waxes. In general, the presence of nanoclay in the carnauba wax formulation greatly enhanced fruit sensory acceptability, nutritional quality and effectively prevented fruit weight loss during storage. Moreover, according to several statistical analyses such as cluster analysis, PCoA and Heat map-based surveys, the carnauba wax-nanoclay emulsions possessed similar behaviors with the maximum efficiency and placed accordingly in the same cluster, while the other four treatments were lonely occupied the next positions. Such nano-formulations could propose as a promising and cost-effective alternative avenue for commercial fruit waxes, towards sustainable postharvest management in retarding respiration rates and weight loss alongside preserving sensory and nutritional quality of fruits. [ABSTRACT FROM AUTHOR]

Boron biocides belong to the most frequently used ingredients of commercial wood preservatives. They are very effective fungicides and insecticides, but they do not react with wood and thus leach from it in wet applications. This fact signifi cantly limits use of boron compounds in the field of wood preservation. In order to reduce leaching of boric acid, the emulsion of polyethylene (WE1) and an emulsion of oxidized polyethylene (WE6) wax were combined with boric acid (cB = 0.1 % or 0.5 % of boron). Spruce wood specimens were vacuum impregnated and afterwards leached according to the prCEN/TS 15119-1, EN 1250-2 and EN 84 procedures. The results showed that the boron leaching is predominantly infl uenced by moisture content of wood during leaching, and furthermore by the concentration gradient (frequency of water replacement). The fact that the prCEN/TS 15119-1 leaching procedure is less severe than other two methods is also refl ected in the results. The results of the EN 84 and ENV 1250 test are comparable, while the results of the prCEN/TS 15119-1 testing are not in line with the other two methods. Considerable portions of boron are leached from wood in the first leaching cycles, already. WE6 wax emulsion (oxidized polyethylene wax emulsion) in combination with heat treatment reduces boron leaching to a certain extent. On the other hand, impregnation of wood with WE1 (polyethylene wax emulsion) does not reduce it and it even enhances it.

Abstract: Waxes and wax emulsions are one of the most important solutions for non-biocidal wood protection. Wax treated wood is designed for outdoor use, therefore it is of considerable importance to elucidate the influence of weathering on the photodegradation processes. It is presumed, that wax treatment will reduce water uptake and thus reduce or slow down photodegradation processes. In order to test this hypothesis, three types of wax emulsions at two different concentrations were vacuum impregnated into Norway spruce wood specimens: an emulsion of montan wax (LGE), an emulsion of polyethylene (WE1) and an emulsion of oxidized polyethylene (WE6) wax. The samples were exposed to artificial accelerated weathering (AAW) for 500 cycles. Before and after AAW colour, the contact angle of water and moisture content were determined. Chemical and morphological changes at exposed surfaces were also investigated with FTIR spectroscopy and SEM. In parallel, the uptake of wax emulsions and water into the axial surfaces of samples was determined with a tensiometer. The moisture content measurements showed that the best hydrophobic effect was achieved with LGE treated wood, where the lowest colour and FTIR changes were observed as well. These results were supported by tensiometer measurements as well. Presented data clearly showed that high loadings of waxes reduce or at least slow down weathering. Among tested waxes, montan wax was found the most effective. [Copyright &y& Elsevier]

This research evaluates the stability of an aqueous emulsion of acrylic copolymers and waxes. Edelwachs, generally applied on wood, has been recently used as an unconventional medium in contemporary painting. Through Pyrolysis–Gas Chromatography–Mass Spectrometry (Py-GC-MS) and Fourier Transformed Infrared Attenuated Total Reflectance (FT-IR-ATR) analyses, the composition of Edelwachs was defined as a mixture of acrylic polymers (MA, MMA, nBA, nBMA), Carnauba and microcrystalline waxes and additives. Mock-ups-obtained mixing Edelwachs with titanium white, zinc white and ultramarine blue were subjected to UV, high temperatures, and high relative humidity accelerated ageing. The effect of the ageing procedures was evaluated through optical microscopy, colourimetric measurements, FT-IR-ATR, Thermogravimetry and Differential Scanning Calorimetry (TG-DSC) and wettability measures. FT-IR-ATR spectra do not show significant variations in terms of chemical stability, indicating a fair stability of Edelwachs as a painting binder. UV and high temperature treatments show the most relevant effects in terms of colorimetric changes (increasing of b*) and thermal stability. The TG-DSC highlights the influence of the pigments (specifically zinc white) mainly on the thermal behaviour of the acrylates. The unexpected decrease of wettability of the paint films, registered after ageing, may indicate a possible phase separation among acrylates and waxes. [ABSTRACT FROM AUTHOR]