scholarly journals Physicochemical Characterization of a Dental Eggshell Powder Abrasive Material

2017 ◽  
Vol 15 (4) ◽  
pp. e341-e346 ◽  
Author(s):  
Stanley C. Onwubu ◽  
Anisa Vahed ◽  
Shalini Singh ◽  
Krishnan M. Kanny
Keyword(s):  
Surface Roughness ◽  
Particle Size ◽  
Ftir Spectroscopy ◽  
Physicochemical Characterization ◽  
Xrd Analysis ◽  
Physicochemical Characteristics ◽  
Threshold Limit Value ◽  
Abrasive Material ◽  
Limit Value ◽  
Transmission Electron

Background This study aimed to determine the physicochemical characteristics of an eggshell-based dental abrasive material. Methods The eggshell powder abrasive material (EPAM) was synthesized by ball milling eggshell powder and surfactants. Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM) and a laser diffraction particle size analyzer (PSA) were used to characterize EPAM. In addition, the abrasive characteristics of EPAM were evaluated by comparison using poly(methyl methacrylate) (PMMA) resins. Surface roughness (Ra) was measured using a profilometer. Results The FTIR spectroscopy and XRD analysis confirmed that the carbonate product was primarily calcite (97.3%) with traces of graphite 2H (1.3%) and thenardite (1.4%). The TEM imagery revealed irregular particles in EPAM. The PSA analysis of the particle size distribution showed EPAM to be a superfine powder (0.3 μm to 50 nm). In addition, the 50-nm EPAM (Ra = 0.04 μm) measured the lowest Ra value when compared with pumice (Ra = 0.08 μm). Conclusions The salient features of this study indicate that EPAM can naturally replace calcite, which is generally mined and used as a dental abrasive material. In addition, and regarding the abrasive characteristics of EPAM in reducing the surface roughness of PMMA resin specimens, this study conclusively showed that EPAM effectively reduces the surface roughness below the threshold limit value of 0.2 μm. Potentially, EPAM could reduce waste disposal problems while enabling an economic benefit from using eggshell waste material.

scholarly journals Structure and Property Investigation of Composite ZnO/SnO2Nanocrystalline Particles after High-Pressure Treatment

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Sun Zhenya ◽  
Deng Yundi ◽  
Zhang Weiying
Keyword(s):  
Particle Size ◽  
High Pressure ◽  
Sol Gel ◽  
Photocatalytic Property ◽  
Xrd Analysis ◽  
Pressure Treatment ◽  
Visible Absorption ◽  
High Pressure Treatment ◽  
Structure And Property ◽  
Transmission Electron

Composite ZnO/SnO2nanocrystalline particles (ZnO/SnO2) were synthesized by sol-gel method and with treatment of high pressure at 6 GPa. The crystallinity and the particle size of the prepared samples were analyzed by X-ray diffraction (XRD) spectroscopy. The results indicated that all the samples had the good crystallinity, and the particle size of ZnO and ZnO/SnO2decreased after high-pressure treatment. The infrared (IR) spectra showed that the distance of crystal lattice was shortened after high-pressure treatment, and the size distribution became more uneven afterSnO2doping. With the high-resolution transmission electron microscope (HRTEM), we got some morphology information and evidence to support the IR and XRD analysis results. The results of ultraviolet-visible absorption (UV-Vis) spectra showed that ZnO/SnO2might improve the photocatalytic property of the samples after high-pressure treatment.

scholarly journals Chitosan-Coated Flexible Liposomes Magnify the Anticancer Activity and Bioavailability of Docetaxel: Impact on Composition

Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 250 ◽  
Author(s):  
Mohammed Alshraim ◽  
Sibghatullah Sangi ◽  
Gamaleldin Harisa ◽  
Abdullah Alomrani ◽  
Osman Yusuf ◽  
...  
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Physicochemical Characterization ◽  
Sodium Deoxycholate ◽  
Physicochemical Characteristics ◽  
Pharmacokinetic Parameters ◽  
Pharmacokinetic Studies ◽  
Electrostatic Deposition ◽  
Release Profiles

Flexible liposomes (FLs) were developed as promising nano-carriers for anticancer drugs. Coating them with chitosan (CS) could improve their drug delivery properties. The aim of this study was to investigate the physicochemical characteristics, pharmacokinetics behavior, and cytotoxic efficacy of docetaxel (DTX)-loaded CS-coated FLs (C-FLs). DTX-loaded FLs and C-FLs were produced via thin-film evaporation and electrostatic deposition methods, respectively. To explore their physicochemical characterization, the particle size, zeta potential, encapsulation efficiency (EE%), morphology, and DTX release profiles were determined. In addition, pharmacokinetic studies were performed, and cytotoxic effect was assessed using colon cancer cells (HT29). Various FLs, dependent on the type of surfactant, were formed with particle sizes in the nano-range, 137.6 ± 6.3 to 238.2 ± 14.2 nm, and an EE% of 59–94%. Moreover, the zeta potential shifted from a negative to a positive value for C-FL with increased particle size and EE%, and the in vitro sustained-release profiles of C-FL compared to those of FL were evident. The optimized C-FL containing sodium deoxycholate (NDC) and dicetyl phosphate (DP) elicited enhanced pharmacokinetic parameters and cytotoxic efficiency compared to those of the uncoated ones and Onkotaxel®. In conclusion, this approach offers a promising solution for DTX delivery.

scholarly journals Effects of Cobalt Loading, Particle Size, and Calcination Condition on Co/CNT Catalyst Performance in Fischer–Tropsch Reactions

Symmetry ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 7 ◽  
Author(s):  
Omid Akbarzadeh ◽  
Noor Mohd Zabidi ◽  
Yasmin Abdul Wahab ◽  
Nor Hamizi ◽  
Zaira Chowdhury ◽  
...  
Keyword(s):  
Particle Size ◽  
Fixed Bed ◽  
Xrd Analysis ◽  
Bet Surface Area ◽  
Fischer Tropsch ◽  
Strong Electrostatic Adsorption ◽  
Transmission Electron ◽  
Co Conversion ◽  
Cobalt Loading ◽  
Temperature Programmed

The strong electrostatic adsorption (SEA) method was applied to the synthesis of a cobalt (Co) catalyst on a multi-walled carbon nanotube (CNT) support. In order to uptake more of the cobalt cluster with higher dispersion, the CNT was functionalized via acid and thermal treatment. The Co/CNT catalyst samples were characterized by a range of methods including the Brunauer–Emmet–Teller (BET) surface area analyzer, transmission electron microscopy (TEM), X-ray powder diffraction (XRD) analysis, atomic absorption spectroscopy (AAS), and H2-temperature programmed reduction (H2-TPR) analysis. The data from the TEM images revealed that the catalyst was highly dispersed over the external and internal walls of the CNT and that it demonstrated a narrow particle size of 6–8 nm. In addition, the data from the H2-TPR studies showed a lower reduction temperature (420 °C) for the pre-treated catalyst samples. Furthermore, a Fischer–Tropsch synthesis (FTS) reaction was chosen to evaluate the Co/CNT catalyst performance by using a fixed-bed microreactor at different parameters. Finally finding the optimum value of the cobalt loading percentage, particle size, and calcination conditions of Co/CNT catalyst resulted in a CO conversion and C5+ selectivity of 58.7% and 83.2%, respectively.

Effect of Dispersants on Microstructures of Nano Alpha Alumina Developed from Aluminium Dross Waste

2015 ◽  
Vol 1115 ◽  
pp. 378-381 ◽  
Author(s):  
S. Anis Sofia ◽  
Noorasikin Samat ◽  
Meor Yusoff Meor Sulaiman
Keyword(s):  
Particle Size ◽  
Xrd Analysis ◽  
Planetary Mill ◽  
Wet Milling ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Particle Size Analyzer ◽  
Milling Method ◽  
Aluminium Dross ◽  
Alpha Alumina

This paper compares the effect of dispersants which are Sodium Laureth Sulfate (SLS) and distilled water (DW) on the crystallization, particle size distribution and morphological behavior of nanoalpha Alumina (α-Al2O3) synthesized from Aluminium (Al) dross waste. The synthesizing of nanoα-Al2O3 via wet milling method was performed using a planetary mill for 4 hours at a speed of 550 rpm. The nanoα-Al2O3 powders with dispersants were characterized with x-ray diffraction (XRD), particle size analyzer (PSA) and transmission electron microscopy (TEM). XRD analysis shows the broadening and shifting of peaks after the sample was calcined at 1300 °C, indicating high crystallinity. The crystallite size of α-Al2O3 milled with SLS is also smaller than the α-Al2O3 milled with DW. These results are consistent with the PSA analysis in which the graphs displayed a symmetrical trend. Then, the PSA analysis is validated with TEM observation up to 100000x magnification, particularly for α-Al2O3 milled with SLS.

scholarly journals Physicochemical characterization and bioactive compounds of stalk from hot fruits of Capsicum annuum L.

2016 ◽  
Vol 35 (2) ◽  
pp. 199 ◽  
Author(s):  
Jana Simonovska ◽  
Mojca Škerget ◽  
Željko Knez ◽  
Marija Srbinoska ◽  
Zoran Kavrakovski ◽  
...  
Keyword(s):  
Particle Size ◽  
Ftir Spectroscopy ◽  
Volatile Compounds ◽  
Capsicum Annuum ◽  
Bioactive Compounds ◽  
Physicochemical Characterization ◽  
Hot Pepper ◽  
Particle Sizes ◽  
Degradation Temperature ◽  
Residual Weight

In stalk of red hot pepper (<em>Capsicum annuum</em> L.) with 0.25 mm, 0.5 mm and 1.0 mm particle sizes, the quantities of nutritive and volatile compounds, bioactive capsaicin and carotenoids were determined. Furthermore, the stalk was characterized using TGA, DSC and FTIR spectroscopy. The influence of the particle size on the content of proteins, ash and cellulose is insignificant. Compared to 0.5 and 1.0 mm, stalk with 0.25 mm particle size was darker with a deeper yellow-brown color, and richer in microelements. Among the quantified volatile compounds, 6 were esters, 2 terpenoids, and 1 acid. The highest quantity of extract rich fats was obtained from stalk with 0.25 mm particle size by using ethanol, which is more efficient for capsaicin extraction, while <em>n</em>-hexane is efficient for extraction of carotenoids. Stalk with 0.25 mm particle size was characterized with a higher degradation temperature and residual weight.

scholarly journals Effect of Aminosilane Modification on Nanocrystalline Cellulose Properties

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Nurul Hanisah Mohd ◽  
Nur Farahein Hadina Ismail ◽  
Johan Iskandar Zahari ◽  
Wan Farahhanim bt Wan Fathilah ◽  
Hanieh Kargarzadeh ◽  
...  
Keyword(s):  
Ftir Spectroscopy ◽  
Elemental Analysis ◽  
Xrd Analysis ◽  
Nanocrystalline Cellulose ◽  
Hydroxyl Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
Empty Fruit Bunches ◽  
Transmission Electron ◽  
Thermal Stability Of

The application of renewable nanomaterials, like nanocrystalline cellulose (NCC), has recently been widely studied by many researchers. NCC has many benefits such as high aspect ratio, biodegradability, and high number of hydroxyl groups which offer great opportunities for modification. In this study, the NCC derived from empty fruit bunches (EFB) was modified with aminosilane, 3-(2-aminoethylamino)propyl-dimethoxymethylsilane (AEAPDMS), and the characterization was performed to investigate the potential as carbon dioxide (CO2) capture. Modification of NCC with AEAPDMS was carried out in water/ethanol solvent (80/20) (v/v) with a ratio of NCC to aminosilane of 1 : 1, 1 : 2, 1 : 3, and 1 : 4 w/w%. The effects of AEAPDMS on NCC were characterized using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD) analysis, elemental analysis (CHNS), and transmission electron microscopy (TEM). The existence of AEAPDMS onto NCC was confirmed by ATR-FTIR spectroscopy as the new peaks of NH2were bending and wagging, and Si-CH3appeared. The thermal stability of NCC increased after modification due to the interaction with AEAPDMS. The elemental analysis result showed that the nitrogen content increased with an enhancement ratio of the modifiers. The XRD indicated that the crystallinity decreased while the rod-like geometry of NCC was maintained after amorphous AEAPDMS grafted on the NCC. Since AEAPDMS can be grafted on the NCC, the sample is applicable as CO2capture.

EXPERIMENTAL SUBSTANTIATION OF THE MAXIMUM ALLOWABLE CONCENTRATION OF DIOCTYL TEREPHTHALATE IN THE AIR OF THE WORKING AREA

2020 ◽  
pp. 34-38
Author(s):  
A. S. Radilov ◽  
S. A. Solntseva ◽  
I. E. Shkaeva ◽  
S. A. Dulov ◽  
E. V. Vivulanets ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Functional State ◽  
Hematological Parameters ◽  
Inhalation Exposure ◽  
Threshold Limit Value ◽  
Maximum Allowable Concentration ◽  
Limit Value ◽  
Threshold Limit ◽  
The Central Nervous System

Toxicity and hazard assessment of dioctyl terephthalate (DOTP) was performed in acute, subacute, and chronic experiments, and its principal toxicometry parameters were determined.It was found that on single exposure DOTP exhibits low toxicity and hazard. No resorptive and irritant effects on skin and mucous membrane of eyes were detected in animal experiments. The single inhalation exposure threshold limit value was set at 300 mg/m3, based on the results of monitoring of the functional state of the central nervous system and myocardium and hematological parameters.Thirty-day subacute experiments (oral administration, inhalation exposure, and skin applications) revealed no accumulation of the compound.Four-month chronic exposure to DOTP aerosols (concentration 96,8 mg/m3) caused disorder of the functional state of the central nervous system and myocardium, changes in the hematological and biochemical parameters, gas and acid-base status of the blood, and morphological changes in the lungs and heart. Embryotoxic, genotoxic and gonadotoxic effects were not detected.The chronic inhalation exposure threshold limit value for DOTP (Limch) was set at 18,6 mg/m3, and the concentration of 3,4 mg/m3 was found to be ineffective.The maximum allowable concentration of DOTP in the air of the working area was set at 3,0 mg/m3, hazard class 3.

Microstructure Characterization of Ag Nanoparticles Prepared by Hydrothermal Method

2012 ◽  
Vol 476-478 ◽  
pp. 1138-1141
Author(s):  
Zhi Qiang Wei ◽  
Qiang Wei ◽  
Li Gang Liu ◽  
Hua Yang ◽  
Xiao Juan Wu
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Hydrothermal Method ◽  
Ag Nanoparticles ◽  
Average Particle Size ◽  
Average Particle ◽  
Face Centered Cubic ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Face Centered

Ag nanoparticles were successfully synthesized by hydrothermal method under the polyol system combined with traces of sodium chloride, Silver nitrate(AgNO3) and polyvinylpyrrolidone (PVP) acted as the silver source and dispersant respectively. The samples by this process were characterized via X-ray powder diffraction (XRD), Brunauer–Emmett–Teller (BET) adsorption equation, transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED) to determine the chemical composition, particle size, crystal structure and morphology. The experiment results indicate that the crystal structure of the samples is face centered cubic (FCC) structure as same as the bulk materials, The specific surface area is 24 m2/g, the particle size distribution ranging from10 to 50 nm, with an average particle size about 26 nm obtained by TEM and confirmed by XRD and BET results.

scholarly journals Microscopic study of zinc nanoparticles synthesised using thermosetting polymer

2019 ◽  
Vol 49 (1) ◽  
Author(s):  
Giriraj Tailor ◽  
Jyoti Chaudhay ◽  
Deepshikha Verma ◽  
Bhupendra Kr. Sarma
Keyword(s):  
Electron Microscope ◽  
Xrd Analysis ◽  
The Novel ◽  
X Ray Diffraction ◽  
Zinc Nanoparticles ◽  
Transmission Electron ◽  
Sem Study ◽  
Zinc Salts ◽  
Thermosetting Polymer ◽  
Low Crystalline

AbstractThe present study reports the novel synthesis of Zinc nanoparticles (Zn NPs) by thermal decomposition method and its characterisation by Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), and X-ray Diffraction Measurements (XRD). Synthesis of Zn NPs was achieved by using thermosetting polymer and zinc salts as precursor. Zn NPs were obtained on calcination at 850 °C for 30 min. SEM study reveals that synthesized nanoparticles are spherical in shape. XRD analysis shows that the Zn NPs formed are low crystalline in nature.

scholarly journals 3D Printing of Drug Nanocrystals for Film Formulations

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3941
Author(s):  
Giorgia Germini ◽  
Leena Peltonen
Keyword(s):  
Particle Size ◽  
3D Printing ◽  
Polymer Films ◽  
Film Studies ◽  
Polymer Concentration ◽  
Physicochemical Characterization ◽  
Methyl Cellulose ◽  
Polymeric Film ◽  
Content Uniformity ◽  
3D Printed

The aim of the study was to prepare indomethacin nanocrystal-loaded, 3D-printed, fast-dissolving oral polymeric film formulations. Nanocrystals were produced by the wet pearl milling technique, and 3D printing was performed by the semi-solid extrusion method. Hydroxypropyl methyl cellulose (HPMC) was the film-forming polymer, and glycerol the plasticizer. In-depth physicochemical characterization was made, including solid-state determination, particle size and size deviation analysis, film appearance evaluation, determination of weight variation, thickness, folding endurance, drug content uniformity, and disintegration time, and drug release testing. In drug nanocrystal studies, three different stabilizers were tested. Poloxamer F68 produced the smallest and most homogeneous particles, with particle size values of 230 nm and PI values below 0.20, and was selected as a stabilizer for the drug-loaded film studies. In printing studies, the polymer concentration was first optimized with drug-free formulations. The best mechanical film properties were achieved for the films with HPMC concentrations of 2.85% (w/w) and 3.5% (w/w), and these two HPMC levels were selected for further drug-loaded film studies. Besides, in the drug-loaded film printing studies, three different drug levels were tested. With the optimum concentration, films were flexible and homogeneous, disintegrated in 1 to 2.5 min, and released the drug in 2–3 min. Drug nanocrystals remained in the nano size range in the polymer films, particle sizes being in all film formulations from 300 to 500 nm. When the 3D-printed polymer films were compared to traditional film-casted polymer films, the physicochemical behavior and pharmaceutical performance of the films were very similar. As a conclusion, 3D printing of drug nanocrystals in oral polymeric film formulations is a very promising option for the production of immediate-release improved- solubility formulations.

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