Valorisation of almond shell waste in ultrasonic biomordanted dyeing: alternatives to metallic mordants

An agroindustrial waste, outer green shell of almond fruit has been valorised as a novel natural dye using chemical solvent-free extraction, small amount of metallic mordants, one-bath biomordanted dyeing, ultrasonic medium, auxiliary-free dyeing and washing. The main objective of this study is to evaluate biomordants vs. metallic mordants depending on heating system both in extraction and dyeing and to reveal alternatives to metallic mordants. Effects of conventional- and ultrasound-assisted systems on dyeing and fastness properties were investigated. Wool fabrics dyed using metallic mordants (alum, iron II sulphate, copper II sulphate and potassium dichromate) were compared with the samples dyed in conjunction with biomordants [powder of valex (acorn of Quercus ithaburensis ssp. macrolepis), pomegranate (Punica granatum L.) rind, rosemary (Rosmarinus officinalis) and thuja (Thuja orientalis) leaves] in terms of colour yield, colour coordinates and fastness properties. Heating system had significant effects on dyeing and fastness results. Power ultrasound did not present any advantage in colour yield increment while it presented different effects on fastness values depending on mordant and process type of which ultrasound was applied. Some biomordants could be replaced with metallic mordants depending on their types and heating system. They could produce completely different colour gamuts just like metallic mordants.     

Atom transfer radical polymerization of methylmethacrylate and styrene initiated by 3,5‐bis(perfluorobenzyloxy)benzyl 2‐bromopropanoate

The synthesis of polymethylmethacrylate (pMMA) and polystyrene (pSt) were realized with newly synthesized initiator, 3,5‐bis(perfluorobenzyloxy)benzyl 2‐bromopropanoate (FBr) in the presence of copper bromide (CuBr) and N,N,N′,N″,N″‐pentamethyl‐diethylenetriamine (PMDETA) by using atom transfer radical polymerization (ATRP). The perfluorinated aromatic group containing initiator was prepared by esterification of the (3,5‐bis[(perfluorobenzyl)oxy]‐phenyl alcohol. Both initiator and polymers were characterized by ¹H‐NMR spectroscopy, gel permeation chromatography, differential scanning calorimetry, and thermogravimetric analysis. The ATRP was supported by an increase in the molecular weight of the forming polymers and also by their monomodal molecular weight distribution. Contact angle measurements of water and ethylene glycol on films of synthesized polymers indicated higher degree of hydrophobicity than that of pure pMMA and pure pSt. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Characterization of an Au/n-Si photovoltaic structure with an organic thin film

We demonstrate that a copper(II) organic complex can control the electrical characteristics of conventional Au/n-Si metal–semiconductor (MS) contacts. We investigated the electronic and photovoltaic properties of a Cu(II) complex/n-Si heterojunction diode. The ideality factor n and barrier height Φ_b of the diode were 2.22 and 0.736 eV, respectively. An ideality factor greater than unity indicates that the diode exhibits non-ideal current–voltage behavior. This behavior results from the effect of series resistance and the presence of an interfacial layer. The series resistance and barrier height determined using Norde’s method were 6.7 kΩ and 0.77 eV, respectively. The device showed photovoltaic behavior, with a maximum open-circuit voltage of 0.24 V and a short circuit current of 1.7 μA under light of 8 mW/cm².     

Combination of Ozonation and Hydrogen Peroxide Bleaching for Linen Fabrics: Optimization of the Process Using Experimental Design Technique

It is well known that ozone can be used as a bleaching agent for cellulosic textile materials. In the context of this study, investigations were undertaken to optimize bleaching of linen fabrics using Box-Behnken Experimental Design. The bleaching process involved two distinct steps where linen fabrics were ozonated under different treatment times then the latter in a subsequent step were subjected to hydrogen peroxide bleaching under a variety of conditions. As a result of study, three optimum recipes were achieved and pretreatment with ozone for 15 min before peroxide bleaching supplies time and chemical savings.     

In situ modification of cyclohexanone formaldehyde resin with boric acid for high‐performance applications

A boron‐containing cyclohexanone formaldehyde resin (BCFR) was synthesized from cyclohexanone, formaldehyde, and boric acid. The effects of the boric acid concentration, solubility, molecular weight, and thermal properties on the product were investigated. Characterization of the BCFRs was done by NMR spectroscopy, gel permeation chromatography, and Fourier transform infrared–attenuated total reflectance spectroscopy. The thermal properties of the samples were determined with differential scanning calorimetry and thermogravimetric analysis. The study results demonstrate that the resin had higher heat‐resistance properties than the commonly modified cyclohexanone formaldehyde resin. The obtained samples were also characterized morphologically by scanning electron microscopy. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

PHOTOINDUCED WETTABILITY OF TITANIUM OXIDE THIN FILMS

We present here the results of a systematic investigation of the influence of the main deposition parameters (substrate temperature, deposition time, reactive gas composition, etc.) on the hydrophilic properties of DC sputtered titania films, grown on heated glass substrates (463?573 K), using water vapors as the reactive gas. Reference samples prepared in standard oxygen-based deposition conditions were used to compare the results. All the investigated samples were polycrystalline, with either pure anatase or mixed anatase-rutile nano-phase mixtures, depending on substrate temperature and film thickness. The surface wettability, evaluated from contact angle data during UV irradiation and in the back-reaction conditions, is discussed in terms of the synergic effects of materials structure, surface morphology, elemental composition, and electronic properties.     

Combining protein micro-phase separation and protein–polysaccharide segregative phase separation to produce gel structures

The ability of protein micro-phase separation and protein–polysaccharide segregative phase separation to generate a range of gel structures and textures was evaluated. Whey protein isolate/κ-carrageenan mixed gels were prepared with 13% (w/v) whey protein isolate, 0–0.6% (w/w) κ-carrageenan and 50, 100 or 250 mM NaCl. The microstructure of gels, determined by confocal laser scanning microscopy, varied from homogenous to protein continuous, bicontinuous, coarse stranded or κ-carrageenan continuous, depending on the κ-carrageenan concentration. Microstructure also varied from stranded to particulate (micro-phase separated) depending on the salt concentration. The rheological behavior of mixed gels corresponded to the shift in the continuous phase from protein to κ-carrageenan. At small concentrations of κ-carrageenan, where carrageenan-rich droplets were dispersed in a continuous protein-rich matrix, gel strength (fracture stress) and firmness (G′) increased due to increased local concentration of proteins caused by phase separation. At higher κ-carrageenan concentrations, gels were substantially less firm, weaker and less deformable (fracture strain). The change in the continuous phase from protein continuous to carrageenan continuous explained the major change in mechanical properties and water-holding properties. The shift in microstructure occurred at lower concentrations of κ-carrageenan when whey proteins were under micro-phase separation conditions. The results demonstrated how the combined mechanisms of ion-induced micro-phase separation of proteins and protein–polysaccharide phase separation and inversion can be used to alter gel structure and texture.     

Speciation of selenium in vitamin tablets using spectrofluorometry following cloud point extraction

Selenium is one of the trace and essential elements for good health but required only in a very narrow range. Hence, determination of selenium in trace level is important. In this work, cloud point extraction (CPE) with non-ionic surfactant Triton X-114 and the fluorometric ligand, 2,3-diaminonaphtalene (DAN) were used for extraction of trace amounts of organic and inorganic selenium species prior to their determination by spectrofluorometry. CPE parameters affecting complexation and phase separation were optimised. The limit of detection calculated by using nine replicate measurements of 0.020 mg/L Se solution after complexing with DAN and 10-fold CPE preconcentration was 2.1 μg/L. Accuracy of the method was checked using EnviroMat Waste Water, EU-L-2 as CRM and result was found to be in good agreement with the certified value. The suggested method can be used for selenium species of selenite, selenate, and total organic selenium at μg/L level.     

Determination of HMF in roasted flour/oil mixtures and effect of solvent used in the extraction procedure

Roasting of flour in oil or fat to form a roux is a common application in the preparation of many foods. In this study the development of 5-(hydroxymethyl)furfural (5-HMF) during roasting of white flour and oil mixtures prepared at 1:1, 1:2 and 1:3 ratios at 120, 160 and 200 °C was investigated. Extraction of 5-HMF from the solids phase, liquid (oil) phase and mixed phase of the samples was performed using three different solvents (water, ether and CCl₄) to evaluate the suitability of these solvents for improvement of the extraction procedure employed in the analysis method. The 5-HMF concentration was determined by using a reversed-phase HPLC system with a C₁₈ column and a photodiode array detector.     

Classification of three Turkish olive cultivars from Aegean region based on their fatty acid composition

In this study, fatty acid compositions of three olive cultivars oils (Ayvalik, Memecik, and Erkence) grown in Aegean region, the major olive production zone of Turkey, were classified by chemometric methods: principal component analysis and discriminant analysis (DA). A total of 187 oil samples were examined over the course of two harvest years (2001–2002 and 2002–2003). The samples were divided into three subgroups according to olive-growing zones: North Aegean (Ayvalik cultivar), South Aegean (Memecik), and İzmir Peninsula (Erkence cultivar). Consistent with discriminant analysis, the predicted groupings in terms of the two harvest years were correctly separated as 98.50 and 96.60%, respectively. In addition to oleic, linoleic, linolenic, margoleic, palmitic/linoleic and linoleic/linolenic were determined to be the best describing components for the oil samples.