scholarly journals Photochemical Reactions in Dialdehyde Starch

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3358 ◽  
Author(s):  
Marta Ziegler-Borowska ◽  
Katarzyna Wegrzynowska-Drzymalska ◽  
Dorota Chelminiak-Dudkiewicz ◽  
Jolanta Kowalonek ◽  
Halina Kaczmarek
Keyword(s):  
Ftir Spectroscopy ◽  
Corn Starch ◽  
Potato Starch ◽  
Photochemical Reactions ◽  
X Ray Diffraction ◽  
Dialdehyde Starch ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Before And After ◽  
Aldehyde Groups

In this study potato and corn starch were subjected to oxidation, using sodium periodate, to obtain dialdehyde starch (DAS) containing different amount of aldehyde groups. The obtained modified starch samples have been characterized with chemical analysis, scanning electron microscopy (SEM) and ATR-FTIR spectroscopy. Then, the samples were exposed to polychromatic UV radiation and the course of photochemical reaction has been monitored with ATR-FTIR spectroscopy. The surface properties of the native and dialdehyde starch before and after UV-irradiation have been determined by contact angle measurements and calculation of surface free energy. The crystallinity of the samples has been estimated with X-ray diffraction (XRD). It has been proved that the dialdehyded corn starch contained a higher amount of functional groups was more photostable than the oxidized potato starch. Sodium iodide(V), firmly bound to DAS macromolecules, has been found to have a significant effect on the photooxidative degradation of the tested systems. In addition, the mechanism of photoinduced reactions in the dialdehyde starch has been proposed.

Surface Treatments of Titanium Alloy for Preparing Laminated Composite Material

2015 ◽  
Vol 1101 ◽  
pp. 229-232 ◽  
Author(s):  
Svetlana Vladimirovna Sibileva ◽  
Andrey Leonidovich Botanogov ◽  
Nikolay Vadimovich Trofimov ◽  
Ludmila Viktorovna Zaharova
Keyword(s):  
Titanium Alloy ◽  
Laminated Composite ◽  
Adhesive Bond ◽  
X Ray Diffraction ◽  
X Ray ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Alloy Vt20 ◽  
Before And After ◽  
Laminated Composite Material

In this investigation surface treatment of titanium alloy VT20 is carried out by phosphating and anodization in order to increase the adhesive bond strength. The surfaces were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), profilometry, contact angle measurements. The joined titanium specimens were shear tested before and after exposure to high humidity to a period of three months.

scholarly journals A Novel Approach for Accelerated Fabrication of Calcium Hydroxyapatite Thin Films

2019 ◽  
Vol 25 (4) ◽  
pp. 365-368
Author(s):  
Pranas USINSKAS ◽  
Živilė STANKEVIČIŪTĖ ◽  
Gediminas NIAURA ◽  
Justinas ČEPONKUS ◽  
Aivaras KAREIVA
Keyword(s):  
Sol Gel ◽  
Calcium Hydroxyapatite ◽  
Xrd Analysis ◽  
Dip Coating ◽  
Complexing Agents ◽  
X Ray Diffraction ◽  
Angle Measurements ◽  
Novel Approach ◽  
Contact Angle Measurements ◽  
Dip Coating Technique

In this study we demonstrate, that sol–gel route is suitable to quicker obtain calcium hydroxyapatite (Ca10(PO4)6(OH)2, CHAp) coatings on crystalline Si substrate by modified dip-coating technique. The substrate was dip-coated by precursor and dried for 10 minutes at 200 °C with following cooling using the heating block for 110 min and annealing at 650 °C. Ethylendiamintetraacetic acid and 1,2-ethandiol, and triethanolamine and polyvinyl alcohol were used as complexing agents and as gel network forming agents, respectively. The obtained coatings were characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), FTIR spectroscopy and contact angle measurements (CAM).

Effect of electron irradiation on the Crystallite size, Grain size and Contact angle of electrodeposited Cadmium Telluride thin films

2015 ◽  
Vol 8 (2) ◽  
Author(s):  
S. A. Gangawane ◽  
V. P. Malekar ◽  
V. J. Fulari
Keyword(s):  
Thin Films ◽  
Contact Angle ◽  
Grain Size ◽  
Electron Beam Irradiation ◽  
Crystal Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Cdte Thin Films

In this paper, the effects of electron beam irradiation on the CdTe thin films are studied. The CdTe thin films are characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and contact angle measurements for different bath concentration. The thin film layers are subjected to irradiation of 6 MeV electrons. Finally the effect of irradiation is correlated to crystal size, grain size and contact angle measurements of the CdTe thin films

Improvement of Hydrophilic Stability of Diamond-Like Carbon Films by O2/CF4 Plasma Post-Treatment

2015 ◽  
Vol 1125 ◽  
pp. 38-44
Author(s):  
Chavin Jongwannasiri ◽  
Shuichi Watanabe
Keyword(s):  
Carbon Films ◽  
Post Treatment ◽  
Attenuated Total Reflectance ◽  
Diamond Like Carbon ◽  
Total Reflectance ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements ◽  
Before And After

In this article, the results obtained from a study carried out on the plasma post-treatment of diamond-like carbon (DLC) films using an oxygen/tetrafluoromethane (O2/CF4) gas mixture is reported. The surface morphology and chemical bonding of the films before and after the plasma post-treatment were characterized using atomic force microscopy (AFM) and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. The effect of adding CF4 to the O2 plasma on the wettability of the films was also examined using contact angle measurements. The results indicate that the surface roughness increased with the addition of CF4 to the O2 plasma, whereas oxygen-and fluorinated-based functional groups were generated on the surface of the DLC films submitted to O2/CF4 plasma post-treatment. The surface energy also decreased with increasing CF4 fraction, causing the surface of the films to be hydrophobic. Furthermore, the films containing 20% CF4 exhibited higher hydrophilic stability than the others. Thus, the addition of a small amount of CF4 to O2 plasma can be considered beneficial in improving the hydrophilic stability of surface of DLC films.

Preparation of N, O-Carboxymethyl Chitosan with Different Substitutional Degree and its Application for Hemostasis

2013 ◽  
Vol 798-799 ◽  
pp. 1061-1066 ◽  
Author(s):  
Yan Wei Zhao ◽  
Lu Liu ◽  
Xiang Han ◽  
Jing Guan
Keyword(s):  
Carboxymethyl Chitosan ◽  
X Ray Diffraction ◽  
Clotting Time ◽  
X Ray ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Ft Ir ◽  
Ubbelohde Viscometer

We prepared N, O-carboxymethyl chitosans (CMCSs) with different substitutional degrees (SDs) to evaluate their effects of hemostasis, and provided experimental basis on biomedical materials. Chloroethanoic acid was used to synthesize CMCSs. The structure were characterized by Fourier transform infrared (FT-IR) and wide-angle X-ray diffraction (WXRD). Potentiometric titration and Ubbelohde viscometer were adopted to determine the SD and intrinsic viscosity of CMCSs. Contact angle measurements were investigated to determine surface wettability. Method of dynamic clotting time and coagulation test in vivo were used to evaluate their effects of hemostasis. SDs of CMCSs were from 50% to 110%. As the SD increased, molecular weight decreased. CMCS powder with SD 63% possessed excellent hemostasis both in vitro and in vivo. CMCS powder owned hemostatic capability prior to CS. CMCS powder with SD 63% (neither too high, nor too low) possessed excellent hemostasis both in vitro and in vivo.

scholarly journals Synthesis and Deposition of Thermochromic VO2 Thin Films from Peroxide-based Chemical Solutions

2021 ◽  
Author(s):  
Matthias Van Zele ◽  
Hannes Rijckaert ◽  
Davy Deduytsche ◽  
Christophe Detavernier ◽  
Isabel Van Driessche ◽  
...  
Keyword(s):  
Coating Thickness ◽  
Optical Transmission ◽  
Solar Modulation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Thermochromic Properties ◽  
Chemical Solutions ◽  
Vo2 Thin Films

In this paper, a novel synthesis for a chemical precursor for nanocrystalline VO2 coatings is elaborated. The compatibility of the precursor towards the substrate is optimized for spin coating. This is done by subjecting multiple solvents to contact angle measurements. A suitable thermal treatment is developed to densify the coating and to induce crystallization. Afterwards the microstructure of the coating is investigated using X-Ray diffraction, electron microscopy and ellipsometry techniques. To assess the thermochromic properties of the fabricated device, optical transmission experiments were conducted both at room temperature and at elevated temperature. A correlation between these thermochromic properties and coating thickness was investigated in order to obtain an optimized thermochromic device, where both high visual transparency and prominent thermochromic switching abilities are aimed for. In this work, an optimal coating thickness is proposed for a thermochromic coating with high switching ability and solar modulation.

Nanotubes Growth on Ti-15Mo Alloys by Anodization at Low Voltage

2016 ◽  
Vol 869 ◽  
pp. 924-929 ◽  
Author(s):  
André Luiz Reis Rangel ◽  
Guilherme Rogeri Moreira Santos ◽  
Ana Paula Rosifini Alves Claro
Keyword(s):  
Positive Characteristic ◽  
Low Voltage ◽  
Ammonium Fluoride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Biological Environment ◽  
Post Implantation ◽  
Microscopy Images

Surface modification by nanotubes growth is an efficient technique to improve the interaction between implant and biological environment. Several studies indicate who low voltages anodizations are able to generate nanotubes with smaller diameters, positive characteristic for the post-implantation cell growth. The aim of this study was to characterize the morphology of the nanotubes formed on Ti-15Mo surfaces applying 5 or 10 V as anodizing voltage. For both conditions were used glycerol based electrolyte with ammonium fluoride and the anodization time was 24 hours. The samples were cleaned in an ultrasonic bath and annealed at 450 ° for 1 hour after anodization. In order to characterize the surfaces were performed scanning electron microscopy images, contact angle measurements and X-ray diffraction analysis. The results confirmed the formation of nanotubes evenly distributed on the surfaces and a direct relation between anodizing voltage and nanotubes diameters.

Amino acid adsorption on tetraphenyl porphyrin films

2020 ◽  
Vol 24 (04) ◽  
pp. 577-588 ◽  
Author(s):  
Jesus M. Rivera ◽  
Margarita Rivera
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Angle Measurements ◽  
Atomic Force ◽  
Tetraphenyl Porphyrin ◽  
Contact Angle Measurements ◽  
Before And After ◽  
Amino Acid Interaction

In this work, metal free, zinc and copper tetraphenyl porphyrin thin films were employed as substrates to study their interaction with glycine, serine, glutamate, lysine and argynine amino acids in order to investigate the effect of the metallic center and the amino acid characteristics in the adsorption phenomena. The amount of amino acid adsorbed on the films was quantified by using the Ruhemann method. Adsorption isotherms were obtained and analyzed in order to predict the adsorption mechanism for each case. In addition, the morphology of the films was investigated before and after the amino acid immersion by using scanning electron and atomic force microscopies. On the other hand, dynamic contact angle measurements were performed to monitor the spreading phenomena and changes in the hydrophobic nature of the surfaces after the amino acid interaction. From the results, it was observed that the largest deposited amino acid on all three surfaces corresponded to the positively charged compounds, while serine was the lowest adsorbed amino acid in all cases. These results can be attributed to electronic interactions between the amino acids’ lateral chains and the electronic [Formula: see text] distribution of the porphyrin macrocycle ring, and they provide important information regarding the amino acid selectivity of adsorption on tetraphenyl porphyrin films.

scholarly journals Strongly Selective Polymer Membranes Modified with Heteroarm Stars for the Ethylene Glycol Dehydration by Pervaporation

Membranes ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 86 ◽  
Author(s):  
Valeriia Rostovtseva ◽  
Alexandra Pulyalina ◽  
Daria Rudakova ◽  
Ludmila Vinogradova ◽  
Galina Polotskaya
Keyword(s):  
Ethylene Glycol ◽  
Membrane System ◽  
Butyl Methacrylate ◽  
Strong Increase ◽  
Separation Performance ◽  
Intrinsic Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Angle Measurements ◽  
Contact Angle Measurements

Hybrid membranes based on poly (2,6-dimethyl-1,4-phenylene oxide) modified with heteroarm stars (HAS) were developed to separate ethylene glycol/water mixtures by pervaporation. The HAS consist of a small branching center fullerene C 60 and twelve arms of different nature, six arms of nonpolar polystyrene and six arms of polar poly-tert-butyl methacrylate. The changes of structure and physical properties with HAS inclusion were systematically studied using SEM, X-ray diffraction analysis, TGA, and contact angle measurements. Mass transfer of ethylene glycol and water through membranes was studied by sorption and pervaporation tests. It was found that the growth of HAS content up to 5 wt% in the membrane leads to an increase in the total flux and a strong increase in the separation factor. To evaluate intrinsic properties of the penetrant–membrane system, permeability and selectivity were calculated. Overall, utilizing star-shaped macromolecules as a filler can be a promising way to improve the separation performance of diffusion membranes.

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