scholarly journals Preparation of Polydimethylsiloxane-Modified Waterborne Polyurethane Coatings for Marine Applications

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4283
Author(s):  
Min-Gu Kim ◽  
Kyoung-Il Jo ◽  
Eunji Kim ◽  
Jae-Hyung Park ◽  
Jae-Wang Ko ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Structural Characteristics ◽  
Testing Machine ◽  
Waterborne Polyurethane ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Water Contact ◽  
X Ray ◽  
Waterborne Polyurethanes ◽  
Marine Applications

A series of waterborne polyurethane dispersions (WPUs) modified with hydroxyl-terminated polydimethylsiloxane (PDMS) were prepared by incorporating PDMS into the soft segments of polyurethane chains. The structural characteristics of the prepared samples were analyzed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and particle size analysis (PSA). The effect of PDMS content on the thermal and mechanical properties of PDMS-modified waterborne polyurethanes (PS-WPU) was investigated. In addition, the water resistance and dimensional stability of the PS-WPU were investigated by measuring its water absorption ratio and water contact angle along with universal testing machine measurements.

Additive-Coated Si3N4 Powder Prepared By The Sol-Gel Method

1994 ◽  
Vol 346 ◽  
Author(s):  
Manzheng Ge ◽  
Honghua Kan ◽  
Hui Yang ◽  
Jianmin Qiao ◽  
Zhonghua Jiang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Coating Layer ◽  
Sol Gel ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Electron Microscopies

ABSTRACTThe Y2O3-La2O3 additive-coated Si3N4 powders of about 1.5 μm in size were prepared by the sol-gel method. X-ray diffraction, X-ray photoelectron spectroscopy, differential thermal analysis, thermogravimetric analysis, electron microscopies, and particle size analysis were used to study the coating on the Si3N4 particles. The results show that properties of the bulk Si3N4 powder are not affected by using the sol-gel coating and the powders are homogeneously coated by a thin layer of the Y2O3-La2O3 additives. The structure of the Y2O3-La2O3 coating layer is amorphous or microcrystalline with a submicron thickness. The coated powders are then more sinterable, and the mechanical properties of the ceramics prepared from such powders are improved.

scholarly journals Photocatalytic treatment based on TiO2 for a coal mining drainage

2021 ◽  
Author(s):  
Julie Joseane Murcia Mesa ◽  
Ceidy Geraldine Patiño Castillo ◽  
Hugo Alfonso Rojas Sarmiento ◽  
José Antonio Navío Santos ◽  
María del Carmen Hidalgo López ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Coal Mining ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
High Concentration ◽  
X Ray ◽  
Ft Ir

The aim of the present work was to evaluate the effectiveness of a heterogeneous photocatalyst based on TiO2 in the treatment of coal mining drainage which contains a variety of heavy metals and high concentration sulfates and sulfides. The photocatalytic behavior of the commercial reference Sigma Aldrich and the different materials synthesized using the Sol-gel methodology with surface modifications using sulfation and fluorination processes were analyzed. To find a possible correlation between the physicochemical properties of photocatalysts and their behavior, a characterization was carried out using X-Ray Diffraction (XRD), X-Ray Fluorescence spectrometry (XRF), Fourier transform infrared spectroscopy (FT–IR), UV–Vis diffuse reflectance Spectra (UV-Vis DRS), N2 physisorption, X-ray photoelectron spectroscopy (XPS), and particle size analysis. Results indicated that the modification of the TiO₂ prepared in the laboratory using sulfation and fluorination allowed the successful control of the physicochemical properties of this oxide. However, commercial TiO2 showed the greatest effectiveness in removing metals such as: Fe, Cu, Cr, and As after a photocatalytic reaction for a maximum of 1 hour under continuous nitrogen flow and a light intensity of 120 W/m2.

scholarly journals Synthesis and Properties of Linear Polyether-Blocked Amino Silicone-Modified Cationic Waterborne Polyurethane

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Chengshu Xu ◽  
Lei OuYang ◽  
Yan Ren ◽  
Zaisheng Cai ◽  
Shaofeng Lu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Soft Segment ◽  
Waterborne Polyurethane ◽  
Adhesive Force ◽  
Chain Extender ◽  
Infrared Spectrometry ◽  
Water Contact ◽  
X Ray ◽  
Force Microscopy ◽  
Amino Silicone

In this study, a waterborne polyurethane (WPU) is synthesized by using polytetramethylene ether glycol (PTMEG) to form the soft segment, 1,4-butanediol (BDO) as the chain extender, n-methyldiethanolamine (MDEA) as a hydrophilic chain extender, and isophorone diisocyanate (IPDI) to form the hard segment. Furthermore, the modified cationic WPU emulsion and its films are created through a reaction between the WPU and a linear polyether-blocked amino silicone (LEPS), which is an organosilicon compound that imparts flexibility. The properties of the structure and formed WPU films are then characterized by using Fourier transform infrared spectrometry, a thermogravimetric analysis, atomic force microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy, as well as by measuring the water contact angle, testing the water absorption, etc. It is found that, with an increase in the LEPS content in the WPU, the particle size of the modified WPU emulsion is increased, the WPU films are more flexible, and the resistance of the modified WPU films to heat and water are increased, while the crystallinity is reduced. The polysiloxane chain segment, which is added to the LEPS-modified WPU emulsion, is significantly enriched on the surface of the modified WPU films, while there are no adverse effects of the LEPS-modified WPU emulsion on the adhesive force between the WPU and substrate. When the LEPS content of the WPU is 14.0 wt%, the modified WPU emulsion and film provide the best performance.

scholarly journals Mining Wastes of an Albite Deposit as Raw Materials for Vitrified Mullite Ceramics

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 232
Author(s):  
Pedro J. Sánchez-Soto ◽  
Eduardo Garzón ◽  
Luis Pérez-Villarejo ◽  
George N. Angelopoulos ◽  
Dolores Eliche-Quesada
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Phase Evolution ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Mining Wastes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Value

In this work, an examination of mining wastes of an albite deposit in south Spain was carried out using X-ray Fluorescence (XRF), X-ray diffraction (XRD), particle size analysis, thermo-dilatometry and Differential Thermal Analysis (DTA) and Thermogravimetric (TG) analysis, followed by the determination of the main ceramic properties. The albite content in two selected samples was high (65–40 wt. %), accompanied by quartz (25–40 wt. %) and other minor minerals identified by XRD, mainly kaolinite, in agreement with the high content of silica and alumina determined by XRF. The content of Na2O was in the range 5.44–3.09 wt. %, being associated with albite. The iron content was very low (<0.75 wt. %). The kaolinite content in the waste was estimated from ~8 to 32 wt. %. The particle size analysis indicated values of 11–31 wt. % of particles <63 µm. The ceramic properties of fired samples (1000–1350 °C) showed progressive shrinkage by the thermal effect, with water absorption and open porosity almost at zero at 1200–1250 °C. At 1200 °C, the bulk density reached a maximum value of 2.38 g/cm3. An abrupt change in the phase evolution by XRD was found from 1150 to 1200 °C, with the disappearance of albite by melting in accordance with the predictions of the phase diagram SiO2-Al2O3-Na2O and the system albite-quartz. These fired materials contained as main crystalline phases quartz and mullite. Quartz was present in the raw samples and mullite was formed by decomposition of kaolinite. The observation of mullite forming needle-shape crystals was revealed by Scanning Electron Microscopy (SEM). The formation of fully densified and vitrified mullite materials by firing treatments was demonstrated.

Preparation of xanthated bentonite and its removal behavior for Pb(II) ions

2010 ◽  
Vol 61 (5) ◽  
pp. 1235-1243 ◽  
Author(s):  
Y. F. He ◽  
F. R. Li ◽  
R. M. Wang ◽  
F. Y. Li ◽  
Y. Wang ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Particle Size Analysis ◽  
Lead Ions ◽  
Size Analysis ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir

Xanthate was successfully grafted onto bentonite by a relatively simple solution reaction. The obtained xanthated bentonite (XBent) was characterized by FT-IR spectrophotometer, thermogravimetric analysis (TG), particle size analysis, x-ray diffraction (XRD) and scanning electron microscopy (SEM). XBent acting as a type of environmentally friendly adsorbent was applied to remove lead ions from aqueous solutions. The optimum conditions were as follows: [Pb2 + ] = 500 mg L−1, [XBent] = 2 g L−1, pH = 5.0; oscillating 60 min under 200 rpm at 25°C. The removal rate of lead was up to 99.9%. It was found that the lead(II) ions—XBent adsorption isotherm model fitted well to the Freundlich isotherm. The adsorption mechanism was also investigated by SEM and XRD, which concluded that lead ions were complexed or chelated with XBent. XBent appears to have potential to be used later in water treatment as a type of inorganic polymer reagent.

scholarly journals Recycling of Waste Solution after Hydrothermal Conversion of Fly Ash on a Semi-Technical Scale for Zeolite Synthesis

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1413
Author(s):  
Rafał Panek ◽  
Jarosław Madej ◽  
Lidia Bandura ◽  
Grzegorz Słowik
Keyword(s):  
Fly Ash ◽  
Nitrogen Adsorption ◽  
Particle Size Analysis ◽  
Al2o3 Content ◽  
Size Analysis ◽  
Zeolite Synthesis ◽  
Hydrothermal Conversion ◽  
Waste Solution ◽  
X Ray ◽  
X Zeolites

Nowadays, using fly ash for zeolites production has become a well-known strategy aimed on sustainable development. During zeolite synthesis in a hydrothermal conversion large amount of post-reaction solution is generated. In this work, the solution was used as a substrate for Na-A and Na-X zeolites synthesis at laboratory and technical scale. Obtained materials were characterized using particle size analysis, X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), transmission electron microscopy (TEM), Fourier transformed infrared spectroscopy (FTIR), and nitrogen adsorption/desorption isotherm. Produced zeolites revealed high purity (>98%) and monomineral zeolitic phase composition. The SiO2 content was in the range 39–42% and 40–38%, whereas Al2O3 content was 23–22% and 25–26% for Na-X and Na-A, respectively. TEM and BET analyses revealed Na-X zeolite pores were almost identical to commercial 13X with SBET in the range 671–734 m2/g. FTIR indicated slight differences between materials obtained at laboratory and technical scale in Si-O-(Si/Al) bridges of the zeolitic skeleton. The results showed good replicability of the laboratory process in the larger scale. The proposed method allows for waste solution reusability with a view to highly pure zeolites production in line with circular economy assumptions.

Synthesis of Alpha-Tricalcium Phosphate by Wet Reaction and Evaluation of Mechanical Properties

2012 ◽  
Vol 727-728 ◽  
pp. 1164-1169 ◽  
Author(s):  
Mônica Beatriz Thürmer ◽  
Rafaela Silveira Vieira ◽  
Juliana Machado Fernandes ◽  
Wilbur Trajano Guerin Coelho ◽  
Luis Alberto Santos
Keyword(s):  
Mechanical Properties ◽  
Calcium Phosphate ◽  
Tricalcium Phosphate ◽  
Calcium Nitrate ◽  
Chemical Precipitation ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcium Phosphate Cements

Calcium phosphate cements have bioactivity and osteoconductivity and can be molded and replace portions of bone tissue. The aim of this work was to study the obtainment of α-tricalcium phosphate, the main phase of calcium phosphate cement, by wet reaction from calcium nitrate and phosphoric acid. There are no reports about α-tricalcium phosphate obtained by this method. Two routes of chemical precipitation were evaluated and the use of two calcinations temperatures to obtain the phase of cement. The influence of calcination temperature on the mechanical properties of cement was evaluated. Cement samples were characterized by particle size analysis, X-ray diffraction, mechanical strength and scanning electron microscopy. The results demonstrate the strong influence of synthesis route on the crystalline phases of cement and the influence of concentration of reactants on the product of the reaction, as well as, on the mechanical properties of cement.

Silver mirror reaction metallized chromatography paper for supercapacitor application

2021 ◽  
Author(s):  
I-Hsuan Chen ◽  
Jung-Hsien Chang ◽  
Ren-Jie Xie ◽  
Chia-Hui Tseng ◽  
Sheng-Rong Hsieh ◽  
...  
Keyword(s):  
Flexible Electronics ◽  
Photoelectron Spectroscopy ◽  
Cost Effective ◽  
Water Contact ◽  
X Ray ◽  
Supercapacitor Application ◽  
Resource Limited ◽  
Vis Spectroscopy ◽  
Silver Mirror ◽  
Silver Mirror Reaction

Abstract In this study, the easy-to-operate silver mirror reaction (SMR) was used for metallizing chromatography paper. The SMR-metallized paper was characterized by water contact angle measurements, a surface profiler, X-ray photoelectron spectroscopy, UV-vis spectroscopy, X-ray diffraction, and electrical resistance measurement. The characterization results show that Ag was successfully synthesized on cellulose fibers and was electrically conductive after cyclic bending. Moreover, this SMR-metallized paper was used as electrodes for fabricating a supercapacitor. This SMR-metallized paper could be used for realizing cost-effective flexible electronics applied in on-site biochemical sensing in resource-limited settings.

X-ray fluorescence spectrometry for rapid screening of particle size in soils

2021 ◽  
Author(s):  
Maame Croffie ◽  
Paul N. Williams ◽  
Owen Fenton ◽  
Anna Fenelon ◽  
Karen Daly
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Soil Texture ◽  
Particle Size Analysis ◽  
Parent Material ◽  
Fluorescence Spectrometry ◽  
Rapid Screening ◽  
Size Analysis ◽  
X Ray

&lt;p&gt;Soil texture is an essential factor for effective land management in agricultural production. Knowledge of soil texture and particle size at field scale can aid with on-going soil management decisions. Standard soil physical and gravimetric methods for particle size analysis are time-consuming and X-ray fluorescence spectrometry (XRF) provides a rapid and cost-effective alternative. The objective of this study was to explore the use of XRF as a predictor for particle size. An extensive archive of Irish soils with particle size and soil texture data was used to select samples for XRF analysis. Regression and correlation analyses on XRF determined results showed that the relationship between Rb and % clay varied with soil type and was dependent on the parent material. There was a strong relationship (R &gt; 0.62, R&lt;sup&gt;2&lt;/sup&gt;&gt;0.30, p&lt;0.05) between Rb and clay for soils originating from bedrock such as limestones and slate. Contrastingly, no significant relationship (R&lt;0.03, R&lt;sup&gt;2&lt;/sup&gt;=0.00, p&gt;0.05) exists between Rb and % clay for soils originating from granite and gneiss. Furthermore, there was a significant negative correlation (p&lt;0.05) between Rb and % sand. The XRF is a useful technique for rough screening of particle size distribution in soils originating from certain parent materials. Thus, this may contribute to the rapid prediction of soil texture based on knowledge of the particle size distribution.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

scholarly journals Superhydrophobic Film on Hot-Dip Galvanized Steel with Corrosion Resistance and Self-Cleaning Properties

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 687 ◽  
Author(s):  
Chongchong Li ◽  
Ruina Ma ◽  
An Du ◽  
Yongzhe Fan ◽  
Xue Zhao ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Photoelectron Spectroscopy ◽  
Copper Nitrate ◽  
Galvanized Steel ◽  
Electrochemical Technique ◽  
Etching Time ◽  
Galvanic Replacement ◽  
Water Contact ◽  
X Ray ◽  
Self Cleaning

Super-hydrophobic film with hierarchical micro/nano structures was prepared by galvanic replacement reaction process on the surface of galvanized steel. The effects of the etching time and copper nitrate concentration on the wetting property of the as-prepared surfaces were studied. Scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and electrochemical technique were employed to characterize the surface morphology, chemical composition, and corrosion resistance. The stability and self-cleaning property of the as-fabricated super-hydrophobic film were also evaluated. The super-hydrophobic film can be obtained within 3 min and possesses a water contact angle of 164.3° ± 2°. Potentiodynamic polarization measurements indicated that the super-hydrophobic film greatly improved the corrosion resistance of the galvanized steel in 3.5 wt % NaCl aqueous solution. The highest inhibition efficiency was estimated to be 96.6%. The obtained super-hydrophobic film showed good stability and self-cleaning property.

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