scholarly journals Coating Characteristic of Hydroxyapatite on Titanium Substrates via Hydrothermal Treatment

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1226
Author(s):  
Pham Trung Kien ◽  
Tran Ngo Quan ◽  
Le Huynh Tuyet Anh
Keyword(s):  
Hydrothermal Treatment ◽  
Treatment Time ◽  
Pure Titanium ◽  
Titanium Substrate ◽  
Optical Microscope ◽  
Initial Fixation ◽  
Phosphate Solutions ◽  
Titanium Substrates ◽  
Hydrothermal Treatment Time ◽  
Hydrothermal Methods

Medical pure titanium (Ti) shows excellent chemical stability and mechanical properties in clinical uses, but its initial fixation with host bone, when implanted, is usually delayed owing to the bioinert Ti surface. In this study, we fabricate the hydroxyapatite (HA)-coated titanium by three steps reactions: (1) to form an activated O2− layer by immersing Ti substrate into an alkaline solution such as NaOH; (2) the O2− bonds with Ca2+ to form Ca–O–Ti bonding, in which O plays the part of bridge materials between Ca and Ti substrate and (3) the conversion of Ca–O–Ti samples to HA-coated Ti samples by immersion into Na2HPO4 2 M at 180 °C for 48 h using hydrothermal methods. The effect of different phosphate solutions (NaH2PO4 2 M and Na2HPO4 2 M solution) and hydrothermal treatment time (24 and 48 h) on the characteristic of hydroxyapatite coating titanium substrate is also investigated using the optical microscope, thin film XRD and SEM/EDX. The HA-coated Ti samples fabricated by immersion into Na2HPO4 2 M at 180 °C for 48 h show fiber HA covering Titan substrate with a diameter varying from 0.1 to 0.3 µm. These HA-coated Ti samples can be regarded as promising multifunctional biomaterials.

scholarly journals Effect of Reaction Time and Hydrothermal Treatment Time on the Textural Properties of SBA-15 Synthesized Using Sodium Silicate as a Silica Source and Its Efficiency for Reducing Tobacco Smoke Toxicity

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 808
Author(s):  
Nerea Juárez-Serrano ◽  
Desiré Berenguer ◽  
Isabel Martínez-Castellanos ◽  
Inmaculada Blasco ◽  
Maribel Beltrán ◽  
...  
Keyword(s):  
Reaction Time ◽  
Hydrothermal Treatment ◽  
Sodium Silicate ◽  
Tobacco Smoking ◽  
Treatment Time ◽  
Textural Properties ◽  
Smoke Toxicity ◽  
Silica Source ◽  
Plant Experiment ◽  
Hydrothermal Treatment Time

The synthesis of SBA-15 has been optimized using sodium silicate, an inexpensive precursor of SBA-15. In this work, the influence of synthesis times of the precipitation and the hydrothermal treatment steps, on the textural properties developed as well as for reducing the toxic compounds generated in tobacco smoking, has been studied. The hydrothermal treatment has been proved to be necessary to obtain materials with adequate performance in this particular application. Twenty-four hours of hydrothermal treatment provide materials with the best properties. Although the reaction stage usually involves the mixing of reagents during 24 h, 40 min is enough to obtain a material with stick-like morphology and typical textural properties. Moreover, between 1 and 2 h of reaction time, the material proved to have the best performance for the purpose of reducing the toxicity of the products generated during the tobacco smoking process. These results are of great significance for an eventual scaling up to industrial scale of the SBA-15 manufacturing process. Results of a pilot plant experiment in a batch of 4 kg of SBA-15 are reported.

scholarly journals Development of a novel sequential pretreatment strategy for the production of bioethanol from coconut pulp residue

2019 ◽  
Vol 1 (3) ◽  
pp. 1-8
Author(s):  
Alissandra Pauline B. Mariano ◽  
Yuwalee Unpaprom ◽  
Rameshprabu Ramaraj
Keyword(s):  
Sulphuric Acid ◽  
Hydrothermal Treatment ◽  
Waste Disposal ◽  
Treatment Time ◽  
Sugar Concentration ◽  
Bioethanol Production ◽  
Cooking Fuel ◽  
Handling Cost ◽  
Sequential Pretreatment ◽  
Hydrothermal Treatment Time

Coconut pulp residues waste generated after extraction of milk or oil. These wastes end up as feed to animals, fertilizers and firewood/cooking fuel whilst large quantities often left to rot in the field, which causes cause pollution, waste disposal problems and increase handling cost for farmers. In order to alleviate this problem, coconut pulp residue was used as feedstock for bioethanol production. However, improvements on pretreatment are necessary to produce higher sugar concentration prior to fermentation. Bioethanol production from coconut pure pulp residue (PPR) and combined pulp residue (CPRS) was investigated. The results showing 40 minutes’ pre-hydrothermal treatment time and 2% mild sulphuric acid for PPR and 20 minutes’ hydrothermal treatment time and 2% mild sulphuric acid for CPRS.

Crystalline microstructure of boehmites studied by multi-peak analysis of powder X-ray diffraction patterns

2017 ◽  
Vol 32 (S1) ◽  
pp. S87-S98 ◽  
Author(s):  
Pablo Pardo ◽  
Marek Andrzej Kojdecki ◽  
José Miguel Calatayud ◽  
José María Amigó ◽  
Javier Alarcón
Keyword(s):  
Hydrothermal Treatment ◽  
Treatment Time ◽  
Crystalline Lattice ◽  
X Ray Diffraction ◽  
Hydrothermal Aging ◽  
X Ray ◽  
Boehmite Nanoparticles ◽  
Diffraction Patterns ◽  
Crystalline Microstructure ◽  
Hydrothermal Treatment Time

Nanocrystalline boehmite (gamma-aluminium-oxyhydroxide) is a material of industrial importance, the functionality of which follows from its crystalline microstructure. A procedure for preparing boehmite nanoparticles, comprising the formation of a precipitate by the alkalization of an aqueous solution of aluminium nitrate and subsequent hydrothermal aging, was previously elaborated. The application of an additive (maltitol or tartaric acid) to control the sizes and shapes of crystallites in the produced polycrystalline powder of boehmite was developed. The aim of this work is a study of the effect of the hydrothermal treatment time on nanocrystalline characteristics of boehmite, both in absence and in presence of the additive. The obtained materials were investigated by using X-ray diffraction (XRD) as principal technique and additionally by scanning and transmission electron microscopy. The multi-peak analysis of powder XRD patterns was applied to determine the prevalent crystallite shape, volume-weighted crystallite size distribution, and second-order crystalline lattice strain distribution being principal quantitative characteristics of the crystalline microstructure. Based on these characteristics, three types of the microstructure correlated with the production procedures were observed and discussed in detail. The nanoparticles of boehmites were found to be monocrystalline grains with characteristic habits and sizes of order of ten nanometers weakly dependent on the hydrothermal treatment time.

Effect of Hydrothermal Treatment in Calcium Phosphate Solution on SUS304 Substrate

2017 ◽  
Vol 264 ◽  
pp. 232-235
Author(s):  
Mohamed Niza Nur Faiqa ◽  
A. Nurazreena
Keyword(s):  
Calcium Phosphate ◽  
Hydrothermal Treatment ◽  
Pitting Corrosion ◽  
Calcium Ions ◽  
Treatment Time ◽  
Cell Attachment ◽  
304 Stainless Steel ◽  
Phosphate Solution ◽  
Iron Release ◽  
Hydrothermal Treatment Time

SUS 304 stainless steel is known to be a biocompatible material and is widely used as screws or plates. However, issues regarding iron ion release after implantation become a concern which limits the application of SUS304. Therefore, to overcome these shortcomings, surface modification on SUS304 by forming calcium layer is needed to disable iron release from the substrate and also to encourage cell attachment. In this study, initially SUS 304 substrate are subjected to electrolysis process in sodium chloride solution to form pitting corrosion. These pitting corrosion will give the anchoring effect for the calcium ions to attach. Then the substrate are subjected to hydrothermal treatment at 200°C in calcium phosphate solution for 24, 36, 48, and 60 hours for deposition of calcium ions on the pitted SUS304 surface. Surface morphology observed by scanning electron microscope (SEM) shows that the calcium ions were deposited on the surface of the SUS304 substrate regardless hydrothermal treatment time. Rockwell hardness values shows that as hydrothermal treatment time increased the hardness value decreases. Therefore, hydrothermal treatment method enables the deposition of calcium ions layer on the surface of SUS304 which will inhibit the release of iron ions and enhanced bone attachment with the implant due to the bonding of the calcium ions with the bone.

Luminescence Properties of ZnS:Cu,Tm Semiconductor Nanocrystals Synthesize by a Hydrothermal Process

2011 ◽  
Vol 415-417 ◽  
pp. 499-503
Author(s):  
Mei Xin ◽  
Dong Ping Liu ◽  
Nai Sen Yu ◽  
Xiao Hui Qi ◽  
Hui Li
Keyword(s):  
Hydrothermal Treatment ◽  
Emission Intensity ◽  
Treatment Time ◽  
Semiconductor Nanocrystals ◽  
Hydrothermal Process ◽  
Luminescence Properties ◽  
X Ray Diffraction ◽  
Pl Emission ◽  
Hydrothermal Approach ◽  
Hydrothermal Treatment Time

ZnS:Cu,Tm nanocrystal with 15nm cubic structures have been synthesized by hydrothermal approach at 200°C. The photoluminescence (PL) properties and the effect of hydrothermal treatment time on the structure, morphology and PL spectra of ZnS:Cu,Tm samples have been studied. The as-obtained samples have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and FT-IR spectra.The result indicated that the PL emission spectrum of codoped with Cu and Tm sample compares with undoped ZnS and doped with Cu alone samples has a significant changes, while the PL emission peak has red shift and PL emission intensity increased. The samples size and crystallization are increase with extending of the treatment time. However, when the hydrothermal treatment time is too long(>12h), the PL emission intensity of sample instead of decreased. Demonstrated changes in surface state of nanomaterials have a greater impact on its luminescence properties.

The effect of hydrothermal treatment time and level of carbon coating on the performance of PtRu/C catalysts in a direct methanol fuel cell

RSC Advances ◽  
2014 ◽  
Vol 4 (109) ◽  
pp. 63922-63932 ◽  
Author(s):  
Cun-Zhi Li ◽  
Zhen-Bo Wang ◽  
Jing Liu ◽  
Chun-Tao Liu ◽  
Da-Ming Gu ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Metal Nanoparticles ◽  
Hydrothermal Treatment ◽  
Direct Methanol Fuel Cell ◽  
Carbon Coating ◽  
Treatment Time ◽  
Direct Methanol ◽  
Methanol Fuel Cell ◽  
Hydrothermal Treatment Time

The existence of carbon nanolayer on the surface of the PtRu/C catalyst from glucosein situcarbonization inhibits the migration and coalescence of PtRu metal nanoparticles on the support.

scholarly journals Synthesis of Mesoporous Cu-Ni/Al2O4 Catalyst for Hydrogen Production via Hydrothermal Reconstruction Route

Catalysts ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 32
Author(s):  
Kai-Jhei Lin ◽  
Yi-Kai Chih ◽  
Wei-Hsin Chen ◽  
Hsin-Kai Huang ◽  
Hong-Ping Lin ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Surface Area ◽  
Calcination Temperature ◽  
Hydrothermal Treatment ◽  
Treatment Time ◽  
Ph Value ◽  
Original Structure ◽  
Activated Alumina ◽  
Reconstruction Process ◽  
Hydrothermal Treatment Time

Mesoporous Cu-Ni/Al2O4 catalyst of high surface area (176 m2g−1) is synthesized through a simple hydrothermal reconstruction process by using low-cost activated alumina as the aluminate source without organic templates. The desired mesoporous structure of the catalyst is formed by the addition of Cu2+ and Ni2+ metal ions in the gel solution of the activated alumina followed by hydrothermal treatment at 70 °C and calcination at temperatures in the range of 600 to 800 °C. To consider the environmental concern, we found the concentration of the Cu2+ and Ni2+ ion in the residual filtrate is less than 0.1 ppm which satisfies the effluent standard in Taiwan (<1.0 ppm). The effects of the pH value, hydrothermal treatment time, and calcination temperature on the structure, morphology and surface area of the synthesized Cu-Ni/Al2O4 composites are investigated as well. In addition, the Cu-Ni/Al2O4 catalyst synthesized at pH 9.0 with a hydrothermal treatment time of 24 h and a calcination temperature of 600 °C is used for hydrogen production via the partial oxidation of methanol. The conversion efficiency is found to be >99% at a reaction temperature of around 315 °C, while the H2 yield is 1.99 mol H2/mol MeOH. The catalyst retains its original structure and surface area following the reaction process, and is thus inferred to have a good stability. Overall, the hydrothermal reconstruction route described herein is facile and easily extendable to the preparation of other mesoporous metal-alumina materials for catalyst applications.

On the Effects of Hydrothermal Treatments on the Corrosion Resistance of the TSA Anodized AA7475-T761 Alloy

2016 ◽  
Vol 710 ◽  
pp. 169-174 ◽  
Author(s):  
Thallis Leal Almeida ◽  
Fernanda Martins Queiroz ◽  
Maysa Terada ◽  
Isolda Costa ◽  
Vera Rosa Capelossi
Keyword(s):  
Electron Microscopy ◽  
Corrosion Resistance ◽  
Hydrothermal Treatment ◽  
Treatment Time ◽  
Electrochemical Impedance ◽  
Anodic Layer ◽  
The Stability ◽  
Kinetics Of ◽  
Hydrothermal Treatment Time ◽  
Scanning Electron

The effect of hydrothermal treatment time on sealing and corrosion resistance of the AA7475-T761 anodized aluminium alloy has been investigated in this study. The hydrothermal treatments tested are environmental compatible without chromium ions involved. Anodizing was carried out by a tartaric-sulphuric anodizing (TSA) process and this was followed by hydrothermal treatments for partial sealing, in various solutions. The effect of propyleneglycol (PRG) and/or cerium ions in the hydrothermal treatment solution was evaluated. Four treatment times were tested, specifically, 2.5, 5.0, 7.5 and 10 min. The corrosion resistance of the anodized and treated samples was evaluated by Electrochemical Impedance Spectroscopy (EIS) and the anodic layers formed were characterized by Scanning Electron Microscopy (SEM). The EIS results showed that the hydrothermal treatments in solutions with cerium ions resulted in similar impedances for periods of treatment from 5 to 10 min whereas in the solutions with PRG the impedance increased with time of treatment from 2.5 to 10 min showing a slower kinetics of anodic layer sealing. However, the fastest kinetics of sealing were associated to the treatments that combined two steps, one in PRG and other in cerium containing solutions with similar impedances obtained from 2.5 to 10 min of treatment. Surface evaluation by SEM showed that the porosities in the anodic layer were not sealed for the periods of hydrothermal treatments corresponding to 2.5 min. The presence of cerium in hydrothermal treatment had a beneficial effect on the stability of the anodic layer formed and provided a healing effect on the corroding sites.

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