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Bio‐inspired and biodegradable quantum optics scenarios constitute a pathway toward environmentally friendly front‐end technologies. Such an inspiring perspective necessitates the replacement of classic gain materials with a biological counterpart like photoluminescent bacteria. It is easy to imagine that, in this case, a planar and cell‐viable substitute of classic bulk solid‐states resonators can be highly beneficial. In this paper a micro‐ and nano‐photonic structuration of both a standard and a functionalized version of a typical bacterial growth medium (Luria‐Bertani Agar – LBA) is successfully realized. Three structures belonging to the categories of photonic crystals are replicated, such as quasi‐crystals and meta‐surfaces, demonstrating how the proposed media can be used as templates for high‐end photonic applications. The optical quality of the replicated structures is confirmed by far‐field diffraction measurements. The structured growth media allow for a broad control of the surface wettability by accessing a so‐called Wenzel state, in which the original hydrophilicity of a material is increased due to the photonic structuration. Finally, the suitability of the nano‐structured LBA as a plasmonic platform is evidenced. The proposed micro‐and nano‐structured photonic growth media constitute the first, fundamental step toward quantum optical frameworks from biological media. [ABSTRACT FROM AUTHOR]

In this study, biofilaments based on cocoa shell waste, a by-product of the chocolate industry, and biodegradable poly(ε-caprolactone), PCL, have been prepared using a single-screw extruder. Micronized cocoa shell waste is compounded in the polymer up to 50% by weight without significant alteration of its crystalline structure. Resultant elastic (Young's) modulus of biofilaments remains close to that of pure PCL. Scanning electron microscopy results indicate that micronized cocoa shell waste is homogeneously dispersed in the polymer during the extrusion process. Detailed thermal characterization measurements on the extruded filaments allow tuning of the fused deposition modeling 3D printing parameters. 3D printed items display a well-defined structure with good adhesion between deposition layers and fine resolution. Hence, with this simple and solvent-free fabrication technique, uniformly structured cocoa shell waste biofilaments can be produced in a very reproducible manner and can be used in 3D printing of diverse objects with potential household and biomedical applications. [ABSTRACT FROM AUTHOR]

ABSTRACT Self-standing films of poly(ω-hydroxyl hexadecanoic acid) [poly(ω-OHC16)] have been prepared by noncatalyzed melt-polycondensation in air at 150, 175, and 200 °C. Poly(ω-OHC16)s obtained are characterized as polyesters by infrared spectroscopy (FT-IR) and solid state magic angle spinning 13C nuclear magnetic resonance (13C MAS-NMR). Structurally, poly(ω-OHC16)s are quite crystalline as revealed by wide angle X-ray diffraction (WAXD). The presence of oxygen in the reaction atmosphere causes a mild oxidation in the form of peroxyester species, tentatively at the interphase between poly(ω-OHC16) crystallites, and the structure amorphization. The interfacial peroxyester phase ends up in the encapsulation of the polyester grains and provides a barrier towards the action of solvents. Thermal stabilization and insolubility resulting from the synthesis conditions used are interesting features to prepare solvent and heat resistant poly(ω-OHC16) coatings. Thus, a few microns thick poly(ω-OHC16) layer has been fabricated on aluminum foil and its resistivity towards a chloroform:methanol (1:1, v:v) mixture has been confirmed. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44350. [ABSTRACT FROM AUTHOR]

A pH-based method to tune the tribological and wetting properties of a coating obtained from water-dispersed perfluorinated acrylic copolymer is demonstrated. The surface-exposed fluorinated chains and chemical charges of the sprayed coatings can be controlled simply by tuning the pH of the initial water dispersion. The surface properties of the sprayed polymeric coatings remain unmodified when the pH of the water dispersion is reduced (addition of HCl). On the contrary, from dispersions with increased pH (addition of NaOH) a fluoroacrylic polyelectrolyte polymer is formed and clear variations in wetting and tribological properties of the polymeric coatings are observed. Interestingly, coatings' surface adhesion to vulcanizing rubber can be strongly reduced when the pH of the dispersions is in the range 4.5-6.0, which corresponds to a specific ratio between fluorinated chains and chemical charges. Consequently, such coatings can be proposed as low-cost and easy-to-apply alternatives to aqueous release agents for the rubber tires demolding processes, thus having significant implications for the automotive tire industry. [ABSTRACT FROM AUTHOR]

ABSTRACT To mimic nontoxic and fully biodegradable biopolymers like the plant cutin, polyester films from a natural occurring fatty polyhydroxyacid like aleuritic (9,10,16-trihydroxyhexadecanoic) acid have been prepared by noncatalyzed melt-polycondensation at moderate temperature (150°C) directly in air. The course of the reaction has been followed by infrared spectroscopy, 13C magic angle spinning nuclear magnetic resonance spectroscopy, differential scanning calorimetry and X-ray diffraction and well differentiated stages are observed. First, a high conversion esterification reaction leads to an amorphous rubbery, infusible, and insoluble material whose structure is made out of ester linkages mostly involving primary hydroxyls and partially branched by minor esterification with secondary ones. Following the esterification stage, the cleavage of vicinal secondary hydroxyls and further oxidation to carboxylic acid is observed at the near surface region of films. New carboxylic groups created also undergo esterification and generate cross-linking points within the polymer structure. Additionally, and despite the harsh preparation conditions used, very little additional side reaction like peroxidation and dehydration are observed. Results demonstrate the feasibility of polyester films fabrication from a reference fatty polyhydroxyacid like aleuritic acid by noncatalyzed melt-polycondensation directly in air. The methodology can potentially be extended to similar natural occurring hydroxyacids to obtain films and coatings to be used, for instance, as nontoxic and biodegradable food packaging material. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41328. [ABSTRACT FROM AUTHOR]

The outer surfaces of epidermal cell walls are impregnated with an extracellular matrix called the cuticle. This composite matrix provides several functions at the interface level that enable plants to thrive in different habitats and withstand adverse environmental conditions. The lipid polymer cutin, which is the main constituent of the plant cuticle, has some unique biophysical properties resulting from its composition and structure. This review summarizes the progress made towards understanding the biophysical significance of this biopolymer with special focus on its structural, thermal, biomechanical, and hydric properties and relationships. The physiological relevance of such biophysical properties is discussed in light of existing knowledge on the plant cuticle. [ABSTRACT FROM AUTHOR]

Beeswax particles are homogenously emulsified in commercial aqueous polymer dispersion, without additional dispersing agents and surfactants. Emulsions display very good stability with wax droplet size distribution around 350 nm. The wax to polymer ratio in the emulsions can be tuned without compromising emulsion stability. The emulsions are spray coated in order to create either hydrophobic or superhydrophobic coatings. For superhydrophobicity, silica nanoparticles are dispersed in the emulsions at different concentrations. Beeswax‐rich coatings such as the ones with 1:1 beeswax:polymer ratio or more, including the superhydrophobic ones, demonstrate promising latent heat storage characteristics, suitable for thermal management applications. Electron microscopy studies show that as a result of emulsification, the polymer encapsulates the wax droplets/particles as a nanothin shell, preventing a major problem related to low melting point phase change materials referred to as leaching. Hence, the coatings can be heated well above the melting point of beeswax (≈62 °C) and can still demonstrate effective heat storage during the cooling stage. This water‐based coating process using ecofriendly material constituents can easily be scaled up and used in responsive coating applications, ranging from electronics to interior or exterior structural buildings requiring efficient energy management and thermal energy savings. Heat storing superhydrophobic nanocomposite coatings are developed by following a totally green process, only water as solvent, and using beeswax as the phase change material. Beeswax is homogenized with an environmentally approved waterborne acrylic dispersion forming very stable microemulsions (≈300 nm). Silica nanoparticle suspended emulsions are applied as superhydrophobic heat storage coatings. [ABSTRACT FROM AUTHOR]

Beeswax is a natural hydrophobic phase change material. Its proper use in superhydrophobic coatings means increased use of eco‐friendly materials in superhydrophobicity and also functionality. These low‐cost coatings can store latent heat and can be eventually implemented in solar heating and cooling of buildings for significant energy savings. More can be found in article number 1801782 by Sara Naderizadeh, Ilker S. Bayer, and co‐workers. [ABSTRACT FROM AUTHOR]