Effect of temperature and treatment time of hydrothermal treatment on crystallization of titanium nitride-hydroxyapatite films coated on polyetheretherketone

Pinus radiata wood was treated under hydrothermal conditions(steam) in an autoclave. The effect of temperature and time were studied. Bending strength, equilibrium moisture content, swelling and pH value of residual water were determined. Following effects were determined: a) a reduction of pH value, b) a considerable reduction of wooden mass, c) a reduction of equilibrium moisture up to 75% air humidity was registered. With higher air humidity no differences between treatments were detected, and d) with higher temperatures and longer treatment time, a reduction of bending strength was ascertained.

Download Full-text

Hydrothermal Growth of Nano-Hydroxyapatite Coating Formed on Fluorinated Magnesium Alloy and Its Corrosion Behaviour

Science of Advanced Materials ◽

10.1166/sam.2021.3842 ◽

2021 ◽

Vol 13 (1) ◽

pp. 10-19

Author(s):

Chun-Yan Zhang ◽

Hao-Lan Fang ◽

Xin-Peng Liu ◽

Fan-Cheng Meng ◽

Zhong-Qing Tian ◽

...

Keyword(s):

Magnesium Alloy ◽

Calcium Phosphate ◽

Hydrothermal Treatment ◽

Treatment Time ◽

Electrochemical Impedance ◽

Hydrothermal Growth ◽

Crystal Phase ◽

Calcium Phosphate Coating ◽

Phosphate Coating ◽

Ha Coating

In order to explore the hydrothermal growth mechanism of hydroxyapatite (HA) coating on fluorinated magnesium alloy, the changes of morphology, composition and crystal phase of the calcium phosphate coating during the hydrothermal treatment were studied. And the change of electrochemical impedance spectroscopy (EIS) of the coating specimen of different hydrothermal treatment time was discussed to further understanding the change of the coating structure. The results demonstrated that calcium phosphate could rapidly nucleate on fluorinated AZ31 magnesium alloy. The crystal phase of calcium phosphate coating was mainly octacalcium phosphate (OCP) at the early stage of hydrothermal treatment. Then the content of OCP decreased and the content of HA increased with hydrothermal time. The coating consisted of only HA after hydrothermal treatment for about 4h. The HA coating composed of rod-like crystals exhibited an obvious double layer structure. The rod-like crystals of inner layer arranged into dense bundles and the rod-like crystals of outer layer arranged into loose chrysanthemum-like clusters. Fluoride conversion layer acted as an intermediate transition layer to connect magnesium alloy and HA coating into a whole. The results of immersion test in simulated body fluid demonstrated that HA crystals dissolved slowly. No peeling occurred of HA coating during the 12 days' immersion. Pitting corrosion was still the mainly corrosion mode of magnesium alloy substrate due to the electrolyte infiltration during the immersion.

Download Full-text

Zinc Oxide Nanoparticles Obtained by Supercritical Antisolvent Precipitation for the Photocatalytic Degradation of Crystal Violet Dye

Catalysts ◽

10.3390/catal9040346 ◽

2019 ◽

Vol 9 (4) ◽

pp. 346 ◽

Cited By ~ 13

Author(s):

Franco ◽

Sacco ◽

De Marco ◽

Vaiano

Keyword(s):

Zinc Oxide ◽

Crystal Violet ◽

Zno Nanoparticles ◽

Treatment Time ◽

Irradiation Time ◽

Effect Of Temperature ◽

Antisolvent Precipitation ◽

Supercritical Antisolvent ◽

Crystal Violet Dye ◽

Mean Diameter

In this work, the synthesis of zinc oxide (ZnO) photocatalyst from thermal decomposition of zinc acetate (ZnAc) nanoparticles obtained by supercritical antisolvent (SAS) precipitation was investigated. The optimization of calcination conditions of the SAS ZnAc was carried out, studying the effect of temperature (in the range 300–600 °C) on the production of ZnO nanoparticles. In particular, it was demonstrated that the organic residues in ZnO and its particle size, thus the specific surface area, strongly affect the photocatalytic performances. SAS micronization of ZnAc produces regular nanoparticles with a mean diameter of about 54.5 ± 11.5 nm, whereas unprocessed ZnAc is characterized by very large crystals. The experimental results evidenced that ZnAc prepared by SAS process calcined at 500 °C showed a regular nanometric structure (mean diameter: 65.0 ± 14.5 nm) and was revealed to be the best choice for the photocatalytic removal of crystal violet dye (CV). In fact, the photocatalytic activity performances of ZnO nanoparticles prepared by this route were higher with respect to that of ZnO from unprocessed ZnAc calcined at 500 °C (which is characterized by irregular tetrapods with mean size 181.1 ± 65.5 nm). The optimized photocatalyst was able to assure the complete CV decolorization in 60 min of UV irradiation time and a mineralization degree higher than 90% after 120 min of treatment time.

Download Full-text

Titanium Nitride Modified by Hydrothermal Treatment in Calcium Acetate Solution

Materials Science Forum ◽

10.4028/www.scientific.net/msf.815.446 ◽

2015 ◽

Vol 815 ◽

pp. 446-450

Author(s):

Xing Ling Shi ◽

Ling Li Xu ◽

Guang Hong Zhou ◽

Le Te Bang

Keyword(s):

Surface Modification ◽

Titanium Nitride ◽

Hydrothermal Treatment ◽

Dental Implant ◽

Pure Titanium ◽

Surface Hardness ◽

Treatment Temperature ◽

Acetate Solution ◽

Tin Coating ◽

Implant Coating

Dental implant made of pure titanium (Ti) has become one important option to restore the function of lost tooth. However, because of insufficient hardness, it is always scratched during oral hygieneprocedures. To improve its surface hardness,titanium nitride (TiN) coating was prepared. Soft tissue - implant interface is important for blocking bacteria invasion, therefore surface modification is necessary to improve biocompatibility of TiN for fibroblasts.In the present study, TiN coating was modified by hydrothermal treatment incalcium acetate (CaAc) solution and effect of hydrothermal treatment temperature was studied. After treatment,calcium (Ca) wassuccessfully combined into TiN surface and the surface morphology, roughness and hardness were not changed below 140 °C. It is expected that, surface modification with Ca by hydrothermal treatment could made TiN a promising dental implant coating.

Download Full-text

Coating Characteristic of Hydroxyapatite on Titanium Substrates via Hydrothermal Treatment

Coatings ◽

10.3390/coatings11101226 ◽

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.

Download Full-text

Sludge pretreatment by sonication: Effect of temperature

Science and Technology Development Journal ◽

10.32508/stdj.v18i4.906 ◽

2015 ◽

Vol 18 (4) ◽

pp. 23-31

Author(s):

Tuan Ngoc Le

Keyword(s):

Treatment Time ◽

Early Stage ◽

Power Input ◽

Effect Of Temperature ◽

Thermal Hydrolysis ◽

Specific Energy Input ◽

Small Probe ◽

Sludge Pretreatment ◽

Cavitation Intensity ◽

Initial Work

Effects of temperature (T) rise in conditions of isothermal, adiabatic sonication -US (the same power input -PUS), and sole thermal hydrolysis, then its effects associated with PUS for the same specific energy input (ES) and the same treatment duration were investigated. The main results were that the evolution of sludge T depended on PUS. In cases of the same ES (different PUS then different US duration), for the small probe, high PUS were still beneficial for sludge disintegration. However, for the big probe, a low disintegration efficiency was achieved at high PUS due to the high sludge T which leads to a significant damp of cavitation intensity. In cases of the same ES and treatment time, the sludge disintegration still benefited from high PUS if enough time was let for subsequent thermal hydrolysis. Therefore, the combined effect should be taken into account in optimization of US process: cavitation acts mainly during the early stage of the adiabatic US, then US being progressively damped by the increasing T, thermal hydrolysis takes over, being “boosted” by the initial work of US.

Download Full-text

Preparation and Characterization of Pr-CeO2 Nano-Powders by Co-Precipitation-Hydrothermal Method

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.368-372.781 ◽

2008 ◽

Vol 368-372 ◽

pp. 781-783

Author(s):

Zhen Feng Zhu ◽

Jing Ping Li ◽

Jun Yang

Keyword(s):

Hydrothermal Method ◽

Hydrothermal Treatment ◽

Treatment Time ◽

Raw Materials ◽

Treatment Temperature ◽

X Ray Diffraction ◽

Transmission Electron ◽

Co Precipitation ◽

Nano Size

Pr-CeO2 nano-size powders with the average crystallites size of 12 nm and particle size of 18 nm were prepared by a co-precipitation-hydrothermal method using Ce(NO3)3·6H2O, Pr6O11 as raw materials and ammonia as the precipitation agent. The influence of hydrothermal treatment time, hydrothermal treatment temperature on the average crystallites size, color of powders and the solubility of praseodymium were investigated. The synthesized powders were characterized by X-ray diffraction, transmission electron microscopy and color measurements. Results showed that after calcining at 800°C for 4 hours, the color of the as-prepared powder changes from light red to red brown, the solubility of praseodymium and the crystallites size of the Pr-CeO2 powder both increase.

Download Full-text

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 ◽

10.3390/catal11070808 ◽

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.

Download Full-text

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

Maejo International Journal of Energy and Environmental Communication ◽

10.54279/mijeec.v1i3.244920 ◽

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.

Download Full-text

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

Powder Diffraction ◽

10.1017/s0885715617000641 ◽

2017 ◽

Vol 32 (S1) ◽

pp. S87-S98 ◽

Cited By ~ 1

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.

Download Full-text