scholarly journals Characterization of PVA-Enzyme Coated Indicator Electrodes GA coated again with PVC-KTpClPB-o-NPOE SEM-EDS, FTIR and XRD analysis

2022 ◽  
Vol 8 (1) ◽  
pp. 103-108
Author(s):  
Abd Hakim S

This study aims to characterize the tungsten-urea analyte indicator electrode. The method used is biosensor potentiometry with urease enzyme immobilization technique. This indicator electrode was coated with PVA-enzyme coated with glutaraldehyde (GA) 2.9% coated with PVC-KTpClPB- o-NPOE with o-NPOE variation of 61% and 66%. Characterization of coated indicator electrodes using SEM-EDS, FTIR and XRD analysis. A1-4 61% indicator electrode sample coated PVA-enzyme 1x coated with glutaraldehyde (GA) 2.9% 1x coated PVC-KTpClPB- o-NPOE 1x, with o-NPOE 61%. A3-4 61% indicator electrode sample coated PVA-enzyme 3x coated with glutaraldehyde (GA) 2.9% 1x coated PVC-KTpClPB- o-NPOE 1x, with o-NPOE 61%. Likewise, the reasoning of samples A1-4 66% and A3-4 66%. There are four indicator electrodes made with the notation A1-4 61%, A1-4 66%, A3-4 61% and A3-4 66%. The best results were obtained at the indicator electrode sample A1-4 61%, contributing to the urea sensor of the potentiometer cell

2021 ◽  
Vol 7 (SpecialIssue) ◽  
pp. 370-376
Author(s):  
Abd Hakim S

This study aims to characterize the phosphate buffer and urease enzymes through UV-Vis and SEM-EDS absorbance spectra using tungsten as an indicator electrode. The method used is a potentiometric biosensor with urease enzyme immobilization technique for urea analyte. A small detection range of 10-5-10-4M has been studied with PVA-enzyme coated indicator electrodes coated with PVC-KTpClPB. On this basis, the researchers increased the detection range by analyzing glutaraldehyde (GA) mixed with PVA-enzyme and o-NPOE mixed with PVC-KTpClPB. The best results of GA mixed PVA-enzyme at GA2.9% UV-Visible analysis. The best results were PVA-enzyme coated indicator electrodes coated with GA coated again with PVC-KTpClPB-o-NPOE SEM-EDS analysis on PVA-enzyme samples 3x coated with GA 1x and PVC-KTpClPB-o-NPOE 1x with o-NPOE variation of 61% and 66%.


2021 ◽  
Vol 7 (3) ◽  
pp. 325
Author(s):  
Victor H Sihombing ◽  
Abd Hakim S

This study aims to characterize phosphate buffer and urease enzymes through the absorbance spectrum of UV-Vis and FTIR using tungsten as the indicator electrode. The method used in this research is the biosensor potentiometric method carried out in the Laboratory of the Faculty of Mathematics and Natural Sciences, State University of Medan and the Beacukai Belawan Medan laboratory. The absorbance characterization of electrolyte solutions in various compositions using UV-Vis showed that phosphate buffer solution 0.001 M pH 7.5+KCl 0.001 M + urea 0.001 M+3 drops urease enzyme had the highest absorbance compared to electrolyte solutions with phosphate buffer and urea content. Likewise, the FTIR results showed the same thing where phosphate buffer solution was 0.001 M pH 7.5 + KCl 0.001 M + urea 0.001 M + 3 drops urease enzyme had the highest% T (transmission) pattern of phosphate buffer solution and urea. The urease enzyme in this study functions as a catalyst. Based on UV-Vis and FTIR characterization, it was concluded that the phosphate buffer solution of 0.001 M pH 7.5+KCl 0.001 M + urea 0.001 M + 3 drops of urease enzyme was the best.


2020 ◽  
Vol 849 ◽  
pp. 113-118
Author(s):  
Yayat Iman Supriyatna ◽  
Slamet Sumardi ◽  
Widi Astuti ◽  
Athessia N. Nainggolan ◽  
Ajeng W. Ismail ◽  
...  

The purpose of this study is to characterize Lampung iron sand and to conduct preliminary experiments on the TiO2 synthesis which can be used for the manufacturing of functional food packaging. The iron sand from South Lampung Regency, Lampung Province that will be utilized as raw material. The experiment was initiated by sieving the iron sand on 80, 100, 150, 200 and 325 mesh sieves. Analysis using X-Ray Fluorescence (XRF) to determine the element content and X-Ray Diffraction (XRD) to observe the mineralization of the iron sand was conducted. The experiment was carried out through the stages of leaching, precipitation, and calcination. Roasting was applied firstly by putting the iron sand into the muffle furnace for 5 hours at a temperature of 700°C. Followed by leaching using HCl for 48 hours and heated at 105°C with a stirring speed of 300 rpm. The leaching solution was filtered with filtrate and solid residue as products. The solid residue was then leached using 10% H2O2 solution. The leached filtrate was heated at 105°C for 40 minutes resulting TiO2 precipitates (powder). Further, the powder was calcined and characterized. Characterization of raw material using XRF shows the major elements of Fe, Ti, Mg, Si, Al and Ca. The highest Ti content is found in mesh 200 with 9.6%, while iron content is about 80.7%. While from the XRD analysis, it shows five mineral types namely magnetite (Fe3O4), Rhodonite (Mn, Fe, Mg, Ca) SiO3, Quart (SiO2), Ilmenite (FeOTiO2) and Rutile (TiO2). The preliminary experiment showed that the Ti content in the synthesized TiO2 powder is 21.2%. The purity of TiO2 is low due to the presence of Fe metal which is dissolved during leaching, so that prior to precipitation purification is needed to remove impurities such as iron and other metals.


1981 ◽  
Vol 6 (2) ◽  
pp. 129-141 ◽  
Author(s):  
S. Gulinelli ◽  
E. Mantovani ◽  
A. Zanobi

2016 ◽  
Vol 98 ◽  
pp. 70-74
Author(s):  
Andrius Laurikėnas ◽  
Jurgis Barkauskas ◽  
Aivaras Kareiva

In this study, lanthanide elements (Ln3+) and 2,3,5,6-tetrafluoro-1,4-benzenedicarboxylic acid (TFBDC) based metal-organic frameworks (MOFs) were synthesized by precipitation and diffusion-controlled precipitation methods. Powders insoluble in aqueous media and polar solvents were obtained. The microstructure and properties of Ln3+ MOFs were evaluated and discussed. X-ray diffraction (XRD) analysis, infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and fluorescence spectroscopy (FLS) were carried out to characterize Ln3+ MOF's crystallinity, the microstructure, chemical composition and optical properties.


2021 ◽  
Vol 17 ◽  
Author(s):  
Amita Sahu ◽  
Sudhanshu Shekhar Swain ◽  
Goutam Ghosh ◽  
Deepak Pradhan ◽  
Dipak Kumar Sahu ◽  
...  

Background: Literature evidences as well as traditional uses of genus Alphonsea reveal significant antimicrobial and anti-oxidant activity, which encourages to consider A. madraspatana to have potent antimicrobials, there by offering potential adjuncts to synthesize improved antimicrobial Silver nanoparticles (AgNPs). The objective of the present exposition is to optimize reaction parameters to synthesize antimicrobial Biogenic Silver nanoparticles (BAgNPs) from extract of A. madraspatana leaves (AML) and to evaluate the effect against bacteria. Methods: BAgNPs was synthesized by optimized reaction. The Synthesized nanoparticles were characterized by UV, IR, ICP-MS and XRD analysis. The antibacterial potency of optimized BAgNPs was evaluated against E. coli by comparing with positive controls. Results: Results of optimization process indicate nanoscale BAgNPs were produced at operating temp. of 45°C for 120 min at pH 8 with 1:5 volume ratio of AgNO3 and extract. Optimized BAgNPs exhibits relatively higher antimicrobial activity (31±1mm) compared to Ciprofloxacin (27±1mm) and marketed nano silver (28± 2 mm). The developed BAgNPs shows comparable biofilm inhibition (86.50%) as compared to marketed nano silver (88.10%) and Ciprofloxacin (83.10%). Conclusion: Experimental evidence suggests methanolic extract of AML under predefined conditions successfully generate nano-template of silver with better antibacterial response against E. coli.


Cerâmica ◽  
2015 ◽  
Vol 61 (358) ◽  
pp. 160-167 ◽  
Author(s):  
A. W. Huang ◽  
C. Santos ◽  
R. O. Magnago ◽  
R. F. F. Silva ◽  
K. Strecker ◽  
...  

<p>Alumina-based ceramics, Al<sub>2</sub>O<sub>3</sub>, exhibit a combination of properties which favor its use as biomaterial, specifically as structural dental prosthesis. Its most important properties as biomaterial are its elevated hardness, chemical stability and biocompatibility. Usually, Al<sub>2</sub>O<sub>3</sub> is processed by solid-state sintering at a temperature of about 1600 <sup>o</sup>C, but it is very difficult to eliminate the porosity due to its diffusional characteristics. The objective of this work was the development and characterization of sintered Al<sub>2</sub>O<sub>3</sub> ceramics, densified with a transient liquid phase formed by a bioactive 3CaO.P<sub>2</sub>O<sub>5</sub>-SiO<sub>2</sub>-MgO glass. Powder mixtures of 90 wt.% Al<sub>2</sub>O<sub>3</sub> and 10 wt.% bioglass were milled, compacted and sintered at 1200 <sup>o</sup>C to 1450 <sup>o</sup>C. Comparatively, monolithic Al<sub>2</sub>O<sub>3</sub> samples were sintered at 1600 <sup>o</sup>C/120 min. The sintered specimens were characterized by relative density, crystalline phases, microstructure and mechanical properties. The results indicate that the specimen sintered at 1450 <sup>o</sup>C/120 min present the best properties. Under this sintering condition, a relative density of 95% was reached, besides hardness higher than 9 GPa and fracture toughness of 6.2 MPa.m<sup>1/2</sup>. XRD analysis indicate alumina (αAl<sub>2</sub>O<sub>3</sub>), whitlockite (3CaO.P<sub>2</sub>O<sub>5</sub>) and diopsite [3(Ca,Mg)O.P<sub>2</sub>O<sub>5</sub>], as crystalline phases. Comparatively, monolithic sintered Al<sub>2</sub>O<sub>3</sub> samples presented 92% of relative density with 17.4 GPa and 3.8 MPa.m<sup>1/2</sup> of hardness and fracture toughness respectively.</p>


2015 ◽  
Vol 75 (7) ◽  
Author(s):  
Amir Arifin ◽  
Abu Bakar Sulong ◽  
Norhamidi Muhamad ◽  
Junaidi Syarif

Hydroxyapatite (HA) has been widely used in biomedical applications due to its excellent biocompatibility. However, Hydroxyapatite possesses poor mechanical properties and only tolerate limited loads for implants. Titanium is well-known materials applied in implant that has advantage in mechanical properties but poor in biocompatibility. The combination of the Titanium alloy and HA is expected to produce bio-implants with good in term of mechanical properties and biocompatabilty. In this work, interaction and mechanical properties of HA/Ti6Al4V was analyzed. The physical and mechanical properties of HA/Ti6Al4V composite powder obtained from compaction (powder metallurgy) of 60 wt.% Ti6Al4V and 40 wt.% HA and sintering at different temperatures in air were investigated in this study. Interactions of the mixed powders were investigated using X-ray diffraction. The hardness and density of the HA/Ti6Al4V composites were also measured. Based on the results of XRD analysis, the oxidation of Ti began at 700 °C. At 1000 °C, two phases were formed (i.e., TiO2 and CaTiO3). The results showed that the hardness HA/Ti6Al4V composites increased by 221.6% with increasing sintering temperature from 700oC to 1000oC. In contrast, the density of the composites decreased by 1.9% with increasing sintering temperature. 


Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3035
Author(s):  
Dovydas Karoblis ◽  
Diana Griesiute ◽  
Kestutis Mazeika ◽  
Dalis Baltrunas ◽  
Dmitry V. Karpinsky ◽  
...  

In this study, a highly crystalline bismuth ferrite (BFO) powder was synthesized using a novel, very simple, and cost-effective synthetic approach. It was demonstrated that the optimal annealing temperature for the preparation of highly-pure BFO is 650 °C. At lower or higher temperatures, the formation of neighboring crystal phases was observed. The thermal behavior of BFO precursor gel was investigated by thermogravimetric and differential scanning calorimetry (TG-DSC) measurements. X-ray diffraction (XRD) analysis and Mössbauer spectroscopy were employed for the investigation of structural properties. Scanning electron microscopy (SEM) was used to evaluate morphological features of the synthesized materials. The obtained powders were also characterized by magnetization measurements, which showed antiferromagnetic behavior of BFO powders.


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