Hasan Türe

Protein network structure and properties of wheat gluten extrudates using a novel solvent-free approach with urea as a combined denaturant and plasticiser

This is, to our knowledge, the first success on solvent-free extrusion of wheat gluten (WG) into high quality films without using NaOH/salicylic acid. It was possible by using urea (concentrations: 10, 15 and 20 wt%) in the single screw-extruder process. Tensile testing, oxygen permeability, water vapor transmission rate, infrared spectroscopy (IR), confocal laser scanning microscopy (CLSM) and protein solubility were used to assess the properties of the extrudates. As the urea concentration increased, the strength and stiffness decreased while the extensibility increased. The oxygen permeability was low and increased, as did the water vapor transmission rate, with increasing urea concentration. The protein solubility of urea-containing films was found to be significantly lower than that of the native gluten and glycerol-plasticized WG extrudate. CLSM, together with the protein solubility, indicated that the urea films were aggregated/polymerized and IR spectroscopy revealed that these films contained a sizeable amount of β-sheets with a high degree of hydrogen bonds associated with protein aggregation. The aggregation did not change with increasing urea concentration, which suggests that the changes in the mechanical and permeability properties were due to urea-induced plasticisation.

Properties of Wheat-Gluten/Montmorillonite Nanocomposite Films Obtained by a Solvent-Free Extrusion Process

This is, to our knowledge, the first study of wheat-gluten-based nanocomposite films prepared by a solvent-free extrusion process. Wheat gluten/montmorillonite nanocomposite films were obtained in a single screw-extruder using urea as a combined denaturant and plasticizer. The oxygen permeability and water vapor transmission rate of the films decreased by respectively factors of 1.9 and 1.3 when 5 wt.% clay was added. At the same time, the stiffness increased by a factor of 1.5, without any critical loss of extensibility. Field emission scanning electron microscopy (FE-SEM) and Energy-dispersive X-ray analysis indicated that the clay particles were layered mainly in the plane of the extruded film. It was possible to identify individual platelets/tactoids with FE-SEM and, together with findings from transmission electron microscopy, atomic force microscopy and X-ray diffraction, it was concluded that the clay existed as individual clay platelets, intercalated tactoids and agglomerates. Thermogravimetric analysis showed that the thermal stability of the extrudates was improved by the addition of clay.

Microfibrillated cellulose and borax as mechanical, O 2 -barrier, and surface-modulating agents of pullulan biocomposite coatings on BOPP

Multifunctional composite coatings on bi-oriented polypropylene (BOPP) films were obtained using borax and microfibrillated cellulose (MFC) added to the main pullulan coating polymer. Spectroscopy analyses suggested that a first type of interaction occurred via hydrogen bonding between the C6OH group of pullulan and the hydroxyl groups of boric acid, while monodiol and didiol complexation represented a second mechanism. The deposition of the coatings yielded an increase in the elastic modulus of the entire plastic substrate (from ∼2GPa of the neat BOPP to ∼3.1GPa of the P/B+/MFC-coated BOPP). The addition of MFC yielded a decrease of both static and kinetic coefficients of friction of approximately 22% and 25%, respectively, as compared to the neat BOPP. All composite coatings dramatically increased the oxygen barrier performance of BOPP, especially under dry conditions. The deposition of the high hydrophilic coatings allowed to obtain highly wettable surfaces (water contact angle of ∼18°).

Characterization of Alginate/Perlite Particles

In this study alginate/perlite composite particles obtained by ionic gelation method were characterized and their usability on the removal of Pb (II) and Ni (II) ions from aqueous solutions was tested. The effects of pH, contact time, initial metal ion level and perlite concentration on the adsorption capacity of particles were investigated in a batch system. Desorption of tested heavy metal ions from particles and reusability of particles were also investigated. Optical microscopy analysis showed that diameters of wet and dried particles were between 2.5-2.8 mm and 1.8-1.9 mm, respectively. Incorporation of perlite decreased the swelling degree of the particles. SEM and SEM-EDX analysis indicated that perlite appeared as thin plates and mainly composed of silica. SEM-EDX also indicated that alginate/perlite particles were composed of C, O, Na, Al, Si, and K. XRD analysis indicated that perlite had amorphous structure and distributed in the alginate matrix. According to TGA analysis, perlite improved the thermal properties of particles. The optimum pH value varied between 6 and 7 for the removal of Pb (II) and Ni (II). The adsorption efficiency of particles reached maximum level while the perlite/alginate (wt. /wt.) ratio was 2.

Manyetik aljinat/perlit kompozit mikrokürelerin karakterizasyonu ve sulu çözeltiden Pb (II) ve Ni (II) iyonlarının uzaklaştırılmasında optimum şartların belirlenmesi

Sunulan calismanin amaci manyetik aljinat/perlit kompozit mikrokurelerin hazirlanmasi, karakterizasyonu ve sentezlenen mikrokurelerin sulu cozeltiden kursun ve nikel agir metal iyonlarinin uzaklastirilmasinda kullanilabilirliginin arastirilmasidir. Mikrokurelerin agir metal adsorpsiyon kapasitesi uzerine perlit konsantrasyonunun, baslangic metal iyon derisiminin ve cozeltinin pH’nin etkileri arastirilmistir. Demir oksit partikulleri basit cokturme yontemiyle, mikrokurelerin sentezinde iyonik jelasyon yontemi kullanilmistir. Demir oksit iceren mikrokurelere perlit eklenmesi ile mikrokurelerin su tutma kapasiteleri azalmistir. SEM analizi mikrokurelerin kuremsi yapida ve yuzeyinin puruzlu oldugunu gostermistir. SEM-EDX analizi manyetik aljinat/perlit mikrokurelerin C, O, Na, Al, Si, K, Cl ve Fe icerdigini ortaya koymustur. XRD analizi sentezlenen demir oksit tozunun Fe 3 O 4 oldugunu belirtmistir. TGA analizi perlit ilavesi ile mikrokurelerin termal dayanikliliklarinin arttigini ortaya koymustur. Perlit/aljinat orani=2 (a/a) oldugunda mikrokurelerin adsorpsiyon kapasitesi maksimuma ulasmis fakat bu orandan fazla perlit ilavesi mikrokurelerin adsorpsiyon kapasitesinde azalmaya neden olmustur.The goal of present study is preparation, characterization of magnetic alginate/perlite composite microspheres and to investigate the usability of produced microspheres for the removal of lead and nickel ions from aqueous solution. The effect of perlite concentration, initial metal ion level and the pH of the solution on the heavy metal adsorption capacity of microspheres were investigated. Iron oxide particles were prepared by simple precipitation method. Ionic gelation method was utilized to synthesize the microspheres. Swelling studies showed that addition of perlite to iron oxide-containing micropsheres decreased the swelling degree of the microspheres. SEM analysis indicated that microspheres were almost * Sorumlu yazar/Corresponding Author 1 Ordu Üniversitesi Fatsa Deniz Bilimleri Fakültesi, Balıkçılık Teknolojisi Mühendisliği, Ordu kaderterzioglu@hotmail.com Ordu Üniversitesi Fatsa Deniz Bilimleri Fakültesi Deniz Bilimleri ve Teknolojisi Mühendisliği, Orduhasanture@odu.edu.tr Ordu Üniversitesi Fatsa Deniz Bilimleri Fakültesi Deniz Bilimleri ve Teknolojisi Mühendisliği, Orduevren_tunca@yahoo.com Sakarya Üniversitesi Fen Bilimleri Enstitüsü Dergisi, 21 (6), 1483~1496, 2017

The effects of alginate microspheres on phytoremediation and growth of Lemna minor in the presence of Cd

ABSTRACT Today, the removal of increased amount of contaminant concentrations in nature such as metals, nanoparticles, has become an essential issue to struggle with. In this paper, both the toxic effects of non-essential Cd on Lemna minor in presence of alginate microspheres and metal removal capacity of Cd-exposed L. minor and microspheres were investigated. Three test groups were constructed: group (L) containing Lemna, group (M) containing alginate microsphere and group (L + M) containing alginate microsphere and Lemna. Five different levels of Cd concentrations were added into these groups. Estimation models were constructed to estimate Cd removal capacities of L. minor and microspheres, and time-concentration-dependent growth (GRC) rates of both microsphere-containing and non-containing groups were modelled by regression analysis. It was seen that microspheres alone only had no positive or negative effects on Lemna growth. It was observed that, for all test groups the time-dependent growth rate has both increase–decrease trends in general. The toxicity effect of Cd on Lemna growth was reduced by adding microspheres into medium. Furthermore, the results stated that test groups containing only microspheres (M, 0–97.56%) and consortium groups (M + L, 0–98.26%) were slightly more successful in Cd removal process compared to Lemna (L) groups (L, 0–97.32%).