scholarly journals The Preparation and Characterization of Alginate–Chitosan Membranes as Solid Support for BTB and Urease Entrapment

Molekul ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 40 ◽  
Author(s):  
Dhony Hermanto ◽  
Mudasir Mudasir ◽  
Dwi Siswanta ◽  
Bambang Kuswandi ◽  
Nurul Ismillayli
Keyword(s):  
Color Change ◽  
Bromothymol Blue ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Chitosan Membrane ◽  
Physical Chemical ◽  
Chitosan Membranes

A study of alginate-chitosan membrane synthesize was done. The membrane was prepared by mixing alginate hydrosol and chitosan hydrosol at mass ratio of 1:1 and pH of 5.28 approximately. Then it was applied for matrix immobilization of urease and bromothymol blue (BTB) by entrapment technique. The physical, chemical, thermal properties of alginate–chitosan membrane and their impact on immobilized urease activity were investigated. The polymer products were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), and Scanning Electron Microscopy (SEM). It’s showed that alginate-chitosan membrane was formed by electrostatic interaction.  The obtained membran has better mechanical properties than original alginat and chitosan membranes. The immobilization urease into alginate-chitosan membrane retained the catalytic activity of the enzyme, as confirmed by color change of BTB indicator after membrane was immersed in substrate solution (urea). Therefore, alginate-chitosan membrane has good characteristics as matrix of enzyme immobilization.

scholarly journals Structural Characterization of Albendazole with the Use of X-Ray Diffraction

2014 ◽  
Vol 70 (a1) ◽  
pp. C1808-C1808 ◽  
Author(s):  
Kelly Lixandrão ◽  
Fabio Ferreira
Keyword(s):  
Crystal Structures ◽  
Structural Characterization ◽  
Rietveld Method ◽  
Low Cost ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Physical Chemical

Drugs may present polycrystalline polymorphism (property of a substance to crystallize in more than one form or crystal structure). These variations can cause changes in physical-chemical properties and differences between the polymorphs as shape, solubility, density, melting range, among other consequences, leading to formulations that are not effective, although the chemical formula is the same [1]. Drugs such as albendazole (C12H15N3O2S, which is one of the most effective anthelmintics, [2] showing activity against nematodes, trematodes and cestodes, reasons that added to its safety and low cost have made it a drug widely used in human medicine and veterinary), has more than two different crystal structures, and only two of them are known. The X-ray powder diffraction is a powerful technique used in the structural characterization of drugs, and coupled with the Rietveld method [4], the quantification of the active phases, through the knowledge of their crystal structures, becomes possible. In this paper we discuss results on the differences between the polymorphs of albendazole, with data obtained by means of X-ray diffraction, thermal analysis (differential scanning calorimetry and thermogravimetric analysis), Fourier transform infrared spectroscopy and scanning electron microscopy.

Studies on the Preparation, Characterization and Solubility of -Cyclodextrin-Roxythromycin Inclusion Complexes

2009 ◽  
Vol 2 (2) ◽  
pp. 523-530
Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Inclusion Complexes ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ir Studies ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.

Characterization of New Nonstoichiometric Ferroelectric (Li0.95Cu0.15)Ta0.76Nb0.19O3 and Comparative Study With (Li0.95Cu0.15)Ta0.57Nb0.38O3 as Photocatalysts in Microbial Fuel Cells

2018 ◽  
Vol 16 (2) ◽  
Author(s):  
S. Louki ◽  
N. Touach ◽  
A. Benzaouak ◽  
V. M. Ortiz-Martínez ◽  
M. J. Salar-García ◽  
...  
Keyword(s):  
Power Density ◽  
Microbial Fuel Cells ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Ferroelectric Material ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Uv Visible

This work investigates the photocatalytic activity of new ferroelectric material with formula (Li0.95Cu0.15)Ta0.76Nb0.19O3 (LT76) in a single chamber microbial fuel cell (MFC) and compares its performance with the similar photocatalyst (Li0.95Cu0.15)Ta0.57Nb0.38O3 (LT57). The photocatalysts LT76 and LT57 were synthesized by ceramic route under the same conditions, with the same starting materials. The ratio Ta/Nb was fixed at 4.0 and 1.5 for LT76 and LT57, respectively. These phases were characterized by different techniques including X-ray diffraction (XRD), transmission electronic microscopy (TEM), particle size distribution (PSD), differential scanning calorimetry (DSC), and ultraviolet (UV)–visible (Vis). The new photocatalyst LT76 presents specific surface area of 0.791 m2/g and Curie temperature of 1197 °C. The photocatalytic efficiency of this material is assessed in terms of wastewater treatment and electricity generation by power density and removal rate of chemical oxygen demand (COD) in the presence of a light source. The values of maximum power density and COD removal were 19.77 mW/m3 and 93%, respectively, for LT76.

scholarly journals Stacking Control by Molecular Symmetry of Sterically Protected Phthalocyanines

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5552
Author(s):  
Ryota Kudo ◽  
Masahiro Sonobe ◽  
Yoshiaki Chino ◽  
Yu Kitazawa ◽  
Mutsumi Kimura
Keyword(s):  
Lamellar Structure ◽  
Synthesis And Characterization ◽  
Molecular Symmetry ◽  
X Ray Diffraction ◽  
Melting Points ◽  
Scanning Calorimetry ◽  
Structural Isomers ◽  
X Ray ◽  
Temperature Controlled

The synthesis and characterization of two phthalocyanine (Pc) structural isomers, 1 and 2, in which four 2,6-di(hexyloxy)phenyl units were attached directly to the 1,8,15,22- or 1,4,15,18-positions of the Pc rings, are described. Both Pcs 1 and 2 exhibited low melting points, i.e., 120 and 130 °C respectively, due to the reduction in intermolecular π-π interaction among the Pc rings caused by the steric hindrance of 2,6-dihexyloxybenzene units. The thermal behaviors were investigated with temperature-controlled polarizing optical microscopy, differential scanning calorimetry, powder X-ray diffraction, and absorption spectral analyses. Pc 1, having C4h molecular symmetry, organized into a lamellar structure containing lateral assemblies of Pc rings. In contrast, the other Pc 2 revealed the formation of metastable crystalline phases, including disordered stacks of Pcs due to rapid cooling from a melted liquid.

scholarly journals Characterization of the Interface Between the Bulk Glass Forming Alloy Zr41Ti14Cu12Ni10Be23 with Pure Metals and Ceramics

2000 ◽  
Vol 15 (7) ◽  
pp. 1617-1621 ◽  
Author(s):  
Jan Schroers ◽  
Konrad Samwer ◽  
Frigyes Szuecs ◽  
William L. Johnson
Keyword(s):  
Sessile Drop ◽  
Bulk Glass ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Glass Forming ◽  
Processing Times ◽  
Thermal Stability Of

The reaction of the bulk glass forming alloy Zr41Ti14Cu12Ni10Be23 (Vit 1) with W, Ta, Mo, AlN, Al2O3, Si, graphite, and amorphous carbon was investigated. Vit 1 samples were melted and subsequently solidified after different processing times on discs of the different materials. Sessile drop examinations of the macroscopic wetting of Vit 1 on the discs as a function of temperature were carried out in situ with a digital optical camera. The reactions at the interfaces between the Vit 1 sample and the different disc materials were investigated with an electron microprobe. The structure and thermal stability of the processed Vit 1 samples were examined by x-ray diffraction and differential scanning calorimetry. The results are discussed in terms of possible applications for composite materials.

Performance of Precursor Materials and Fired Ceramics for Structural Blocks

2015 ◽  
Vol 820 ◽  
pp. 13-17
Author(s):  
Neila Gondim Azeredo ◽  
Euzébio Barnabé Zanelato ◽  
Jonas Alexandre ◽  
Afonso Rangel Garcez de Azevedo ◽  
Gustavo de Castro Xavier ◽  
...  
Keyword(s):  
Building Construction ◽  
Structural Ceramic ◽  
X Ray Diffraction ◽  
Mineralogical Characterization ◽  
X Ray ◽  
Physical Chemical ◽  
Ceramic Blocks ◽  
Clay Body ◽  
Structural Blocks

The physical, chemical and mineralogical characterization of a precursor clay body before firing is of relevance for understanding the technological performance of the fired clay ceramic. In particular, structural clay ceramic blocks used in building construction need to attend standard properties specified by the norms. In the present work the precursor clay body, typically used to fabricate structural blocks in Campos dos Goytacazes, state of Rio de Janeiro, Brazil, was characterized in terms of particle size distribution, X-ray diffraction, chemical composition and Atterberg limits. In addition, the performance of structural ceramic blocks, fabricated from the extruded clay body and fired at 850oC, was evaluated. The results indicated that the ceramic mechanical strength complies with the Brazilian norm but the water absorption is higher than the maximum specified by the norm. The characteristic of the clay body contribute to justify the structural blocks performance.

Optimization of Structure of Soft Block for Design of Adaptive Polyurethanes

2020 ◽  
Vol 869 ◽  
pp. 273-279
Author(s):  
Marina A. Gorbunova ◽  
Denis V. Anokhin ◽  
Valentina A. Lesnichaya ◽  
Alexander A. Grishchuk ◽  
Elmira R. Badamshina
Keyword(s):  
Mutual Influence ◽  
Glycol Adipate ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Crystallization Conditions ◽  
Crystalline Domains ◽  
Kinetics Of

A synthesis of new di-and triblock polyurethane thermoplastic copolymers containing different mass ratio of two crystallizing blocks - poly (1,4-butylene glycol) adipate and poly-ε-caprolactone diols was developed. Using combination of danamometric analysis, IR-spectroscopy, differential scanning calorimetry and X-ray diffraction, the effect of the soft block composition and crystallization conditions on crystal structure and thermal behavior of the obtained polymers have been studied. For the triblock copolymers we have shown a possibility of control the kinetics of material hardening and final mechanical characteristics due to the mutual influence of polydiols during crystallization. In the result, the second crystallizing component allows to control amount, structure and quality of crystalline domains in polyurethanes by variation of crystallization conditions.

scholarly journals Effect of Various Parameters on Bio-Synthesis of Copper Nanoparticles Using Citrus Medica Linn (Lemon) Extract and Its Antibacterial Activity

2020 ◽  
Vol 1 (1) ◽  
pp. 51-58
Author(s):  
Sharmila Pradhan ◽  
Rajeswori Shrestha ◽  
Khuma Bhandari
Keyword(s):  
Antibacterial Activity ◽  
Copper Nanoparticles ◽  
Color Change ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy ◽  
Crystalline Nature ◽  
Bio Synthesis

This research is focused on bio-synthesis of Copper nanoparticles (CuNPs) using lemon extract to study the effect of various parameters on synthesis and to explore antibacterial activity. The biomolecules present in lemon extract act as self reducing and stabilizing agent. The synthesis of CuNPs was found to be affected by various parameters like volume of the lemon extract, concentration of the precursor and the temperature etc. Preliminary characterization of formation of nanoparticles were done by color change and UV-visible (UV-vis) spectroscopy. Elemental composition of the prepared sample was determined via Energy Dispersive X-ray (EDX) Spectroscopy. Presence of important functional groups associated with biomolecules is well characterized by Fourier Transform Infrared spectroscopy (FTIR). Scanning Electron Microscopy (SEM ) revealed the formation agglomerated CuNPs of different shape and sizes and the X-ray diffraction pattern showed the formation of purely crystalline nature of CuNPs. Finally, agar well diffusion method showed that CuNPs have potential antibacterial activity against Gram-ve bacteria compared to Gram +ve bacteria.

The Synthesis and Characterization of Oxide Free Tin Nanoparticles

2014 ◽  
Vol 670-671 ◽  
pp. 26-29
Author(s):  
Zhi Long Pan ◽  
Shi Liang Ao ◽  
Jian Ping Jia
Keyword(s):  
Reduction Method ◽  
Chemical Reduction ◽  
Thermal Characterization ◽  
X Ray Diffraction ◽  
Chemical Reduction Method ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Xrd Study ◽  
Tin Nanoparticles

Oxide free Tin nanoparticles were synthesized from a chemical reduction method. Their morphological and thermal characterizations were studied in this paper. The X-ray diffraction (XRD) study showed that no oxides of Tin nanoparticles were formed. The thermal characterization by differential scanning calorimetry (DSC) exhibited the size dependency of the melting points. The melting point was as low as 202.16°C.

Development and Characterization of Chitosan Membranes as a System for Controlled Release of Piperine

2016 ◽  
Vol 869 ◽  
pp. 864-868
Author(s):  
Imarally Vitor de Souza Ribeiro Nascimento ◽  
Mairly Karolyne da Silva Souza ◽  
Willams Teles Barbosa ◽  
Thiago Bizerra Fideles ◽  
Thais Maria Alves Marinho ◽  
...  
Keyword(s):  
Controlled Release ◽  
Drug Carriers ◽  
Solvent Casting ◽  
X Ray Diffraction ◽  
Casting Method ◽  
Pharmacological Activities ◽  
X Ray ◽  
Natural Alkaloid ◽  
Chitosan Membranes

Among the variety of polymers used as drug carriers, chitosan has received attention in the fields of medicine and pharmacy by being a nontoxic, biocompatible and biodegradable copolymer. Piperine is a natural alkaloid, has various pharmacological activities such as anti-inflammatory, analgesic, antipyretic, hepatoprotective and antitumor when combined with chitosan has better bioavailability and more effectiveness. This work aims to prepare and characterize chitosan / piperine membranes obtained by the solvent casting method. The membranes were characterized by Spectroscopy Fourier Transform Infrared (FTIR), X-ray Diffraction (DRX) and Scanning Electron Microscopy (MEV). From the results obtained it can be concluded that the process described was effective in obtaining the system chitosan/piperine indicating its potential for studies of controlled release of drug.

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