Preparation of Waterborne Polyurethane by Bio-Based Polyol and Study of Nanocomposites with Nanocellulose Particles

2020 ◽  
Vol 20 (8) ◽  
pp. 4873-4877
Author(s):  
Soonmo Choi ◽  
Eunjoo Shin
Keyword(s):  
Waterborne Polyurethane ◽  
Xrd Analysis ◽  
Decomposition Temperature ◽  
Sem Analysis ◽  
Regenerated Cellulose ◽  
Initial Modulus ◽  
A Chain ◽  
Average Size ◽  
20 Nm ◽  
Low Crystallinity

In this study, we environment-friendly developed bio-based waterborne polyurethane (BWPU) through the use of both harmless water to human instead of organic solvent and natural castor oil-based polyols. Also, high crystallinity cellulose nanocrystals (CNCs) and regenerated cellulose nanoparticles (RCNs) with low crystallinity as reinforcing agents were prepared through H2SO4 and NaOH/urea methods, respectively. In SEM analysis, we defined that the CNC rod-like particles have a length of 100~200 nm and a width of several tens nm and that the average size of RCNs with round shape was 7~20 nm. It was shown that the crystallinity of CNCs was higher than RCNs’ via FTIR and XRD analysis. In addition, it was found that as the contents of CNCs and RCNs increased, so did the properties of strength, initial modulus, and strain. It could be established that all results mentioned were constituted by the hydrogen bonding between the -OH group of nanocellulose and the -NCO group of BWPU constitutes as well as the role of nanocellulose as a chain extender. Furthermore, the maximum decomposition temperature increased with raising the content of nanocellulose. This tendency was more favorable for CNCs with higher crystallinity than RCNs with low crystallinity.

Study on Nano-TiO2 Film Prepared by Hydrothermal Method in Toluene-Hydrochloric Acid-Water System

2012 ◽  
Vol 610-613 ◽  
pp. 3247-3251 ◽  
Author(s):  
Xian Guang Zeng ◽  
Jia Zhuang ◽  
Min Gong ◽  
Xing Wen Zheng ◽  
Ming Tian Li
Keyword(s):  
Methylene Blue ◽  
Hydrochloric Acid ◽  
Hydrothermal Method ◽  
Tio2 Film ◽  
Water System ◽  
Photocatalytic Property ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Tetrabutyl Titanate ◽  
Average Size

A new hydrothermal method was introduced to prepare TiO2 films. The films were prepared by using tetrabutyl titanate as precursor, toluene as solvent and hydrochloric acid as the inhibitor via a facile hydrothermal method. XRD, SEM, AFM, and TG-DSC were used to characterize phase structure and morphology of TiO2 thin films. XRD analysis showed that crystal phase of as- prepared films were anatase entirely,and its average size was 9 nm. AFM and SEM analysis indicated that films had nanocrystallines,and it was homogenous,dense and crack- free. Photocatalytic properties of TiO2 film were estimated by degradation of methylene blue . The result shows that the degradation rate of 40mL methylene blue solution with initial concentration 10 mg/L reaches to 52.8 % after irradiated for 120 min under 35W ultraviolet lamp ,and as-prepared TiO2 film has better photocatalytic property.

scholarly journals Synthesis of SiO2-TiO2:Yb3+ glass-ceramics and characterization of structure and optical properties

2017 ◽  
Vol 1 (T1) ◽  
pp. 114-121
Author(s):  
Thanh Tat Huynh ◽  
Van Thi Thanh Tran
Keyword(s):  
Sol Gel ◽  
Glass Ceramics ◽  
Xrd Analysis ◽  
Silica Matrix ◽  
Photoluminescence Intensity ◽  
Raman Spectroscopic ◽  
Characteristic Emission ◽  
Ft Ir ◽  
Average Size ◽  
20 Nm

In this work, the monoliths of 85 % SiO2-15 % TiO2 doped Yb3+ ions at different contents have been prepared by sol-gel method. The measurement of FT-IR, Raman spectroscopic and XRD analysis show the formation of anatase TiO2 nanocrystals with average size about 15–20 nm in silica matrix. Moreover, the pyrochlore crystals of Yb2Ti2O7 begin to form in the samples when content of Yb3+ reaches to 1 mol %. TiO2 Yb3+ 2F7/2 2F5/2 truyền năng lƣợng kích thích UV EV EC mức khuyết tật 974 nm The energy transferred from TiO2 crystals to Yb3+ ions is proven by the characteristic emission spectrum of Yb3+ at the wavelength of 980 nm when the samples are excited by the wavelength of 300 nm. The photoluminescence intensity is highest at 0.1% mol of Yb3+ and gradually decreases with doping content

Morphological and Optical Characterization of Gold Nanoparticles Decorated Porous Silicon

2019 ◽  
Vol 19 (6) ◽  
pp. 3604-3609
Author(s):  
F Severiano ◽  
V. L Gayou ◽  
G García ◽  
J. A Luna-López ◽  
H. Martínez Gutiérrez ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Porous Silicon ◽  
Chemical Etching ◽  
Silicon Layer ◽  
Porous Silicon Layer ◽  
Sem Analysis ◽  
Etching Time ◽  
Si Nanocrystals ◽  
Average Size ◽  
20 Nm

In this article, physical characteristics of porous silicon (PS) obtained by electro chemical etching using HAuCl4 in the electrolyte are described. The morphological and optical features of PS decorated with gold-nanoparticles (AuNPs) were analyzed in function of the chemical etching time. The insertion of AuNPs inside the PS were performed simultaneously with the formation of the porous silicon layer. Scanning electron microscopy (SEM) analysis showed the formation and incorporation of AuNPs with an average size of 20 nm in the PS structure, which has a pore size of 1.5 μm. Also, it was possible to observe the loss of Si in function of the etching time. Photoluminescence spectroscopy analysis shows a decreasing of the PL intensity, which can be related to the presence of oxygen in the samples. Raman spectroscopy was used to estimate the size of the Si nanocrystals in the PS structure, which suffers a reduction in size due to the presence of HAuCl4 in the electrolyte.

Phyllantus Emblica Mediated Silica Nanomaterials: Biosynthesis, Structural and Stability Analysis

2021 ◽  
Author(s):  
M Sankareswaran ◽  
M Vanitha ◽  
P. Rajiv ◽  
A. Anbukumaran
Keyword(s):  
Silica Nanoparticles ◽  
Research Work ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Weight Percentage ◽  
Ir Studies ◽  
Silica Nanomaterials ◽  
Crystalline Nature ◽  
Size Of Particles ◽  
Average Size

Abstract The current investigation reports on a green route, simple and eco-friendly method for synthesis of silica nanoparticles from Phyllantus emblica. Appropriate characterization techniques were employed to assess the crystalline nature, microstructure, size, purity, elemental composition and stability of as-biosynthesized silica nanoparticles. The XRD analysis showed a wide-ranging peak at 22∘ of 2θ value and proved that the nanoparticles were crystalline nature with 32 nm average size of particles. FT-IR studies confirmed the occurrence of metal oxide group and presence of phyto-molecules namely hydroxyl, amide, and carboxyl functional groups, which were responsible for formation and stabilization of silica nanomaterials. TGA and Zeta potential analysis determined that silica nanoparticles are highly thermostable. EDX analysis revealed the purity of nanomaterials and spectra confirmed that formation of silica nanomaterials (72.97 weight percentage of SiO2 content) with low impurities. SEM analysis shows that the particles are spherical in shape with low agglomeration. This research work concluded that the P. emblica was an excellent and reliable green resource for production of highly stable and potential silica nanoparticles.

scholarly journals Sonochemical synthesis and chracterization of Mn3O4 nanoparticles

2010 ◽  
Vol 8 (3) ◽  
pp. 633-638 ◽  
Author(s):  
Abdulhadi Baykal ◽  
Hüseyin Kavas ◽  
Zehra Durmuş ◽  
Mine Demir ◽  
Sinan Kazan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Xrd Analysis ◽  
Blocking Temperature ◽  
Sonochemical Method ◽  
Tem Analysis ◽  
Mn Oxide ◽  
Profile Fitting ◽  
Average Size ◽  
20 Nm ◽  
Mn3o4 Nanoparticles

AbstractWe report on the synthesis of Mn3O4 nanoparticles (NPs) using a novel sonochemical method without requiring any pH adjustment. Synthesized material was identified as tetragonal hausmannite crystal structure model of Mn3O4 from XRD analysis. Crystallite size was estimated from x-ray line profile fitting to be 17±5 nm. FTIR analysis revealed stretching vibrations of metal ions in tetrahedral and octahedral coordination confirming the crystal structure. TEM analysis revealed a dominantly cubic morphology of NPs with an average size of ∼20 nm. Magnetic evaluation revealed a blocking temperature, T B of 40 K above which the material behaves paramagnetic. Asymmetric coercive field is attributed to the interaction between ferromagnetic Mn3O4 and antiferromagnetic Mn oxide at the surface of nanoparticles.

Characterization of mechanochemically synthesized lead selenide

2009 ◽  
Vol 63 (5) ◽  
Author(s):  
Marcela Achimovičová ◽  
Nina Daneu ◽  
Aleksander Rečnik ◽  
Juraj Ďurišin ◽  
Baláž Peter ◽  
...  
Keyword(s):  
Mechanochemical Synthesis ◽  
Lead Selenide ◽  
Blue Shift ◽  
Xrd Analysis ◽  
High Energy ◽  
Sem Analysis ◽  
Area Measurement ◽  
Distribution Analysis ◽  
Average Size

AbstractMechanochemical synthesis of lead selenide PbSe nanocrystals was performed by high-energy milling of lead and selenium powders in a planetary ball mill. The structure properties of synthesized lead selenide were characterized by XRD analysis that confirmed crystalline nature of PbSe nanocrystals. Calculated average size of PbSe crystallites was 37 nm. The methods of particle size distribution analysis, specific surface area measurement, SEM and TEM were used for the characterization of surface and morphology of PbSe nanocrystals. SEM analysis revealed agglomerates of PbSe particles. However, HRTEM analysis confirmed perfect stoichiometric PbSe cubes with NaCl structure as well. UV-VIS-NIR spectrophotometry was used to confirm the blue shift of the small particles occurring in the powder product obtained by the mechanochemical synthesis.

Spark Plasma Sintering of Hybrid Nanocomposites of Hydroxyapatite Reinforced with CNTs and SS316L for Biomedical Applications

2020 ◽  
Vol 16 (4) ◽  
pp. 578-583
Author(s):  
Muhammad Asif Hussain ◽  
Adnan Maqbool ◽  
Abbas Saeed Hakeem ◽  
Fazal Ahmad Khalid ◽  
Muhammad Asif Rafiq ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Spark Plasma Sintering ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Hybrid Nanocomposites ◽  
Homogeneous Distribution ◽  
Sintering Behavior ◽  
Stainless Steel 316L ◽  
Plasma Sintering ◽  
Spark Plasma

Background: The development of new bioimplants with enhanced mechanical and biomedical properties have great impetus for researchers in the field of biomaterials. Metallic materials such as stainless steel 316L (SS316L), applied for bioimplants are compatible to the human osteoblast cells and bear good toughness. However, they suffer by corrosion and their elastic moduli are very high than the application where they need to be used. On the other hand, ceramics such as hydroxyapatite (HAP), is biocompatible as well as bioactive material and helps in bone grafting during the course of bone recovery, it has the inherent brittle nature and low fracture toughness. Therefore, to overcome these issues, a hybrid combination of HAP, SS316L and carbon nanotubes (CNTs) has been synthesized and characterized in the present investigation. Methods: CNTs were acid treated to functionalize their surface and cleaned prior their addition to the composites. The mixing of nano-hydroxyapatite (HAPn), SS316L and CNTs was carried out by nitrogen gas purging followed by the ball milling to insure the homogeneous mixing of the powders. In three compositions, monolithic HAPn, nanocomposites of CNTs reinforced HAPn, and hybrid nanocomposites of CNTs and SS316L reinforced HAPn has been fabricated by spark plasma sintering (SPS) technique. Results: SEM analysis of SPS samples showed enhanced sintering of HAP-CNT nanocomposites, which also showed significant sintering behavior when combined with SS316L. Good densification was achieved in the nanocomposites. No phase change was observed for HAP at relatively higher sintering temperatures (1100°C) of SPS and tricalcium phosphate phase was not detected by XRD analysis. This represents the characteristic advantage with enhanced sintering behavior by SPS technique. Fracture toughness was found to increase with the addition of CNTs and SS316L in HAPn, while hardness initially enhanced with the addition of nonreinforcement (CNTs) in HAPn and then decrease for HAPn-CNT-SS316L hybrid nanocomposites due to presence of SS316L. Conclusion: A homogeneous distribution of CNTs and SPS technique resulted in the improved mechanical properties for HAPn-CNT-SS316L hybrid nanocomposites than other composites and suggested their application as bioimplant materials.

scholarly journals Functional Attributes of Myco-Synthesized Silver Nanoparticles from Endophytic Fungi: A New Implication in Biomedical Applications

Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 473
Author(s):  
Prabu Kumar Seetharaman ◽  
Rajkuberan Chandrasekaran ◽  
Rajiv Periakaruppan ◽  
Sathishkumar Gnanasekar ◽  
Sivaramakrishnan Sivaperumal ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Culture Filtrate ◽  
Morphological Changes ◽  
Xrd Analysis ◽  
Penicillium Oxalicum ◽  
Breast Cancer Cell Lines ◽  
Face Centered Cubic ◽  
Tem Analysis ◽  
X Ray ◽  
Average Size

To develop a benign nanomaterial from biogenic sources, we have attempted to formulate and fabricate silver nanoparticles synthesized from the culture filtrate of an endophytic fungus Penicillium oxalicum strain LA-1 (PoAgNPs). The synthesized PoAgNPs were exclusively characterized through UV–vis absorption spectroscopy, Fourier Transform Infra-Red spectroscopy (FT-IR), X-ray powder diffraction (XRD), and Transmission Electron Microscopy (TEM) with energy dispersive X-ray spectroscopy (EDX). The synthesized nanoparticles showed strong absorbance around 430 nm with surface plasmon resonance (SPR) and exhibited a face-centered cubic crystalline nature in XRD analysis. Proteins presented in the culture filtrate acted as reducing, capping, and stabilization agents to form PoAgNPs. TEM analysis revealed the generation of polydispersed spherical PoAgNPs with an average size of 52.26 nm. The PoAgNPs showed excellent antibacterial activity against bacterial pathogens. The PoAgNPs induced a dose-dependent cytotoxic activity against human adenocarcinoma breast cancer cell lines (MDA-MB-231), and apoptotic morphological changes were observed by dual staining. Additionally, PoAgNPs demonstrated better larvicidal activity against the larvae of Culex quinquefasciatus. Moreover, the hemolytic test indicated that the as-synthesized PoAgNPs are a safe and biocompatible nanomaterial with versatile bio-applications.

scholarly journals Preparation and characterization of corn starch/PVA/glycerol composite films incorporated with ε-polylysine as a novel antimicrobial packaging material

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 154-161 ◽  
Author(s):  
Gao Yurong ◽  
Li Dapeng
Keyword(s):  
Water Solubility ◽  
Corn Starch ◽  
Composite Films ◽  
Antimicrobial Properties ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Packaging Material ◽  
Hydroxyl Group ◽  
Electron Microscopic ◽  
Antimicrobial Packaging

AbstractCorn starch/polyvinyl alcohol (PVA)/glycerol composite films incorporated with ε-polylysine were prepared, and their properties were investigated. The Fourier-transform infrared (FTIR) spectroscopy indicated that the interactions happened between the amino group of ε-polylysine and hydroxyl group starch/PVA composite films. X-ray diffraction (XRD) analysis showed that the addition of ε-polylysine decreased the intensity of all crystal peaks. Thermogravimetric (TGA) analysis suggested that ε-polylysine improved the thermal stability of composite films. Scanning electron microscopic (SEM) analysis showed that the upper surface of composite films incorporated with ε-polylysine presented more compact and flat surface. The antimicrobial activity of the composite film progressively increased with the increasing of ε-polylysine concentration (P < 0.05). The tensile strength, elongation at break and water absorption significantly increased, whereas water solubility decreased with the increasing of ε-polylysine concentration (P < 0.05). Therefore, the corn starch/PVA/glycerol composite films incorporated with ε-polylysine had good mechanical, physical and antimicrobial properties and could have potential application as a novel antimicrobial packaging material.

scholarly journals A Comparative Evaluation of Nanohydroxyapatite-Enriched Hydrogen Peroxide Home Bleaching System on Color, Hardness and Microstructure of Dental Enamel

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3072
Author(s):  
Riccardo Monterubbianesi ◽  
Vincenzo Tosco ◽  
Tiziano Bellezze ◽  
Giampaolo Giuliani ◽  
Mutlu Özcan ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Particle Diameter ◽  
Dental Enamel ◽  
Sem Analysis ◽  
Control Group ◽  
Average Particle ◽  
Color Analysis ◽  
Enamel Microstructure ◽  
Prismatic Structure ◽  
20 Nm

This study aimed to evaluate two hydrogen peroxide (HP)-based at-home bleaching systems in order to analyze whether nano-hydroxyapatite (nHA) addition may represent a reliable and safe solution for tooth whitening without altering dental microstructure and hardness. Human third molars (N = 15) were treated with two bleaching agents, one containing 6%HP (6HP) and the other 6% HP nHA-enriched (6HP-nHA) with average particle diameter ranging from 5–20 nm. Their effects on enamel were assessed using a spectrophotometer, Vickers microhardness (VMH) test and Scanning Electron Microscopy (SEM), comparing the treated groups with the non-treated control group (CTR). Color analysis revealed improvement in whiteness in both groups compared to CTR. VMH test results showed no differences among the groups. SEM analysis highlighted no evident changes in the enamel microstructure of tested groups compared to CTR. At high magnification, in 6HP group, a slight increase in irregularities of enamel surface morphology was observed, while 6HP-nHA group displayed removal of the aprismatic layer but preservation of the intact prismatic structure. These results suggest that the 6HP-nHA agent may be recommended to provide reliable whitening treatment, without damaging the enamel micromorphology and hardness.

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