Oil Binding Ability of Chlorinated and Heated Wheat Starch Granules and Their Use in Breadmaking and Pancake Baking

Chlorination and heat treatment of wheat flour changes the surface character of starch granules from hydrophilic to hydrophobic, and high oil binding ability of the starch granules can be observed. It was suggested that the hydrophobicity, in case of chlorination, was due to chemical modification of the starch granule surface proteins, and, in case of heat treatment, due to conformational changes of the proteins. This hydrophobicity could be also obtained by aging (233 days at room temperature). The hydrophobicity of starch granules in batter is highly related to the springiness of pancake. Heat treated wheat starch granules can encapsulate flavor through their oil binding ability.     

A new insight into the adsorption mechanism of patulin by the heat-inactive lactic acid bacteria cells

The primary objective of this study was to identify the characteristics of the heat-inactived lactic acid bacteria (LAB) cells involved in the adsorption of patulin. The bacterial cells were characterized by Scanning Electron Microscopy coupled with Energy Dispersive X-Ray Spectroscopy (SEM-EDS), Transmission Electron Microscopy (TEM) and Brunauer–Emmett–Teller (BET) technique. The patulin-exposed bacterial cells and patulin-unexposed bacterial cells were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Zeta Potential and Contact Angle Method. It was found that Lactobacillus brevis 20023 (LB-20023), which has the highest specific surface area and cell wall volume, showed the highest capacity to adsorb patulin from the aqueous solution. Five major elements (C, N, O, P, and S) were detected by SEM-EDS, and LB-20023 displayed the highest nitrogen-to-carbon (N/C) ratio (0.2938). LB-20023 exhibited the highest hydrophobicity, but the zeta potential was not prominent compared to other bacterial cells. The main functional groups involved in adsorbing patulin were C–O, OH and/or NH groups, suggesting that polysaccharides and/or protein were important functional components. Above all, the adsorption capacity of bacterial cells had close relationships with physical and chemical properties of cell surface, including specific surface area, cell wall volume, nitrogen-to-carbon (N/C) ratio, hydrophobicity and functional groups. Further study will be needed to find other additional functional factors.     

Vapor Phase Beckmann Rearrangement of Cyclohexanone Oxime Over Rare Earth Pyrophosphates

A new application of rare earth pyrophosphates in vapor phase Beckmann rearrangement of cyclohexanone oxime was investigated. The rare earth phosphates were characterized by means of XRD, FT-IR, NH₃-TPD and water contact angle measurement. It was found that the weak surface acidity and appropriate surface hydrophobicity should be two key factors in the excellent performance of these catalysts.     

Miniemulsion polymerization of vegetable oil macromonomers

The Thames Research Group developed vegetable oil macromonomer (VOMM) technology to combine the advantages of oil-modified polyesters and waterborne systems, and reduce volatile organic compounds in waterborne coatings. VOMMs offer the advantage of temporary plasticization with the potential for crosslinking after film formation. However, incorporating VOMMs into emulsions is challenging because the highly hydrophobic nature of VOMMs restricts their diffusion through the water phase. Miniemulsion polymerization has been used to incorporate highly hydrophobic monomers in waterborne systems. Diffusion limitations are avoided by polymerizing inside the monomer droplets, and to ensure this, droplet stabilization is required. In our study, a soybean oil-based VOMM was used as a copolymerizable hydrophobe in miniemulsion polymerization. Monomer droplets were stabilized prior to polymerization via catastrophic phase inversion to form stable and small droplets (100 nm). Dynamic light scattering analysis was used to confirm miniemulsion stability. A coagulum-free latex was obtained after polymerization. Surface tension studies and light scattering techniques were used to confirm that monomer droplet nucleation was the dominant mechanism. Gel content studies indicated the formation of a highly branched or crosslinked network upon film application. The miniemulsion technique permitted VOMM incorporation as high as 35 wt% into the polymer backbone.     

Copper based hydrophobic ceramic nanocoating

A mechanism for the development of nanocoatings for the tiles industry by using copper nanoparticles has been proposed. A standard processing procedure in which ceramics were fast-firing at 1200 °C in air atmosphere simulating an industrial process was followed. The ceramic nanocoating was multifunctional having shine metallic aspect and hydrophobic characteristics. The surface crystallizations were studied by X-ray diffraction and corresponded to copper oxide nanocrystals. The hydrophobic response was based in the nanoroughness of the surface and correlated with the Cu⁺/Cu²⁺ ratio as determined by XANES. The cellular nano microstructure look biomimetic with the one of hydrophobic leafs. The development of the cellular nano microstructure was based on the Rayleigh-Bernard cells of a saturated glass during cooling in which thermal convection currents allow the crystallization of nanoparticles at the surface of the glass.     

Microphase separation and hydrophobicity of urethane/siloxane copolymers with low siloxane content

Polyurethane–siloxane thermoset copolymers were obtained from Isophorone diisocyanate trimer, Polycaprolactone triol and 10% of hydroxy terminated Polydimethyl siloxane. The copolymers showed a phase separated structure that depended on the conversion of the reaction and casting temperature. The different samples obtained had water contact angles higher than 90°. Moreover the contact angle values presented a maximum at intermediate reaction conversion. Although FTIR measurements showed that siloxane concentration at the surface increased with reaction time, the maximum contact angle value was related to the higher roughness calculated from AFM images. DMTA results confirmed that the phase separation was higher at intermediate conversions.     

The modelling technology of protective silicone coatings in terms of selected physical properties: Hydrophobicity,scrub resistance and water vapour diffusion

This paper deals with an analysis of the simultaneous influence of the factors of the silicone coating manufacturing process, such as the contents of the organic and silicone resins used in the paint formulations, on selected physical parameters determining the quality of the coatings: hydrophobicity, resistance to wet scrubbing and the ability to diffuse water vapour through the coatings. This analysis was performed using statistical models based on multiple regression analysis. The proposed statistical models proved to be useful for the optimization of the recipe configurations for silicone coatings. Combining the analysis results enabled the selection of the optimal ranges of values for the analysed factors, from a physical as well as an economic point of view.     

Adhesion aspects of hydrophobic silane zeolite coatings for corrosion protection of aluminium substrate

The adhesive properties of an anti-corrosion silane–zeolite coatings on aluminium substrates have been evaluated in this work. The coated samples were obtained by dip-coating sol–gel solution. Four different composite coatings at increasing zeolite amount (60–90 wt% of zeolite) have been investigated.     

A high accurate static contact angle algorithm based on Hough transformation

The static contact angle for blurry drop images is more intricate to obtain. To improve the accuracy of the Hough transformation for the static contact angle calculation, the water drop images with different volumes are generated by the Laplace equation, and the influence of the volume on the accuracy of the Hough transformation is analyzed. The results reveal that the circle Hough transformation is particularly well suited to the cases with small drop volume. At the same time, the critical water drop volume value corresponding to a contact angle error of 3° is given, a modified Hough transformation algorithm in conjunction with the critical water drop volume is proposed, and at the same time, the accuracy of the static contact angle calculation for blurry water drop images is significantly improved. The proposed algorithm is a powerful approach to estimate the static contact angle for blurry water drop images.     

Bioflocculation of mesophilic and thermophilic activated sludge

Thermophilic activated sludge treatment is often hampered by a turbid effluent. Reasons for this phenomenon are so far unknown. Here, the hypothesis of the temperature dependency of the hydrophobic interaction as a possible cause for diminished thermophilic activated sludge bioflocculation was tested. Adsorption of wastewater colloidal particles was monitored on different flat surfaces as a function of temperature. Adsorption on a hydrophobic surface varied with temperature between 20 and 60 degrees C and no upward or downward trend could be observed. This makes the hydrophobic interaction hypothesis unlikely in explaining the differences in mesophilic and thermophilic activated sludge bioflocculation. Both mesophilic and thermophilic biomass did not flocculate with wastewater colloidal particles under anaerobic conditions. Only in the presence of oxygen, with biologically active bacteria, the differences in bioflocculation behavior became evident. Bioflocculation was shown only to occur with the combination of wastewater and viable mesophilic biomass at 30 degrees C, in the presence of oxygen. Bioflocculation did not occur in case the biomass was inactivated or when oxygen was absent. Thermophilic activated sludge hardly showed any bioflocculation, also under mesophilic conditions. Despite the differences in bioflocculation behavior, sludge hydrophobicity and sludge zetapotentials were almost similar. Theoretical calculations using the DLVO (Derjaguin, Landau, Verweij and Overbeek) theory showed that flocculation is unlikely in all cases due to long-range electrostatic forces. These calculations, combined with the fact that bioflocculation actually did occur at 30 degrees C and the unlikelyness of the hydrophobic interaction, point in the direction of bacterial exo-polymers governing bridging flocculation. Polymer interactions are not included in the DLVO theory and may vary as a function of temperature.