Effect of hydrothermal treatment temperature on the hydroxyapatite coatings deposited by electrochemical method

2021 ◽  
Vol 406 ◽  
pp. 126656
Author(s):  
Daihua He ◽  
Xuexian Zhang ◽  
Ping Liu ◽  
Xinkuan Liu ◽  
Xiaohong Chen ◽  
...  
Fermentation ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 81
Author(s):  
Hironaga Akita ◽  
Mohd Zulkhairi Mohd Yusoff ◽  
Shinji Fujimoto

Malaysia is the second largest palm oil producer and exporter globally. When crude palm oil is produced in both plantations and oil processing mills, a large amount of oil palm empty fruit bunch (OPEFB) is simultaneously produced as a waste product. Here, we describe the preparation of hydrolysate from OPEFB. After OPEFB was hydrothermally treated at 180–200 °C, the resultant liquid phase was subjected to high-performance liquid chromatography analysis, while the solid phase was used for acidic and enzymatic hydrolysis. Hemicellulose yield from the acid-treated solid phase decreased from 153 mg/g-OPEFB to 27.5 mg/g-OPEFB by increasing the hydrothermal treatment temperature from 180 to 200 °C. Glucose yield from the enzyme-treated solid phase obtained after hydrothermal treatment at 200 °C was the highest (234 ± 1.90 mg/g-OPEFB, 61.7% production efficiency). In contrast, xylose, mannose, galactose, and arabinose yields in the hydrolysate prepared from the solid phase hydrothermally treated at 200 °C were the lowest. Thus, we concluded that the optimum temperature for hydrothermal pretreatment was 200 °C, which was caused by the low hemicellulose yield. Based on these results, we have established an effective method for preparing OPEFB hydrolysates with high glucose content.


2015 ◽  
Vol 815 ◽  
pp. 446-450
Author(s):  
Xing Ling Shi ◽  
Ling Li Xu ◽  
Guang Hong Zhou ◽  
Le Te Bang

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.


2009 ◽  
Vol 16 (05) ◽  
pp. 675-681 ◽  
Author(s):  
DONG-MEI LI ◽  
XIN-BO XIONG ◽  
XIE-RONG ZENG ◽  
CHUN-LI ZOU ◽  
JI-ZHAO ZOU

Carbon/carbon composites with hydroxyapatite coatings are one of the attractive materials in the dental and orthopedic fields. In this study, hydrothermal treatment, in KOH aqueous and ammonia solutions, was used to convert an induction-heating-deposited monetite coating to an adherent HA coating on H2O2 treated C/C composites. The structure, morphology and chemical composition of the as-received HA coatings were characterized by XRD, FTIR, SEM and EDS. A scratch test was conducted to measure the adhesion of HA coatings to HT – C/C substrate. The results show that well-crystallized carbonate hydroxyapatite coatings could be achieved under the two reaction mediums. However, the as-obtained HA coatings after KOH hydrothermal treatment have higher crystallinity and Ca/P ratio than those after ammonia hydrothermal treatment, and reveal an average critical load of 29 N which is more than two times as high as that for HA coatings after ammonia hydrothermal treatment.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Sheng Wang ◽  
Tao Wang ◽  
Yuanwei Ding ◽  
Youfeng Xu ◽  
Qiying Su ◽  
...  

By changing hydrothermal condition and post-heat-treatment temperature, silica-coatedTiO2nanotubes are obtained successfully. The effects of gas-supported process on tubular morphology, crystallinity, and photocatalytic activity are discussed. It is found that the sample prepared at hydrothermal treatment (180°C/9 h) and calcination (650°C/2 h) shows perfect open-ended tubular morphology and increased crystallinity. The photoactivity of the sample is proved to be 5 times higher than that ofTiO2nanoparticles.


2014 ◽  
Vol 1024 ◽  
pp. 263-266 ◽  
Author(s):  
Chris Salim ◽  
Niki Prastomo ◽  
Yan Shao ◽  
Hirofumi Hinode

Sidoarjo mudflow occurred in 2006 has been causing major environmental problems in a wide area surrounding the region. The utilization of the sludge from this mudflow as useful materials is a potential solution to this problem. In this study, we proposed a hydrothermal treatment method to convert the silica-rich sludge into zeolites useful as adsorbent for inorganic pollutants such as heavy metals. Prior to the hydrothermal treatment, the sludge was contacted with NaOH solution in a teflon vessel. During the hydrothermal treatment, the mixture was subjected to increasing temperature for a certain period of time. After hydrothermal treatment, the solid phase was filtered, washed thoroughly until neutral pH and dried. In this study, we evaluated the effect of NaOH concentration and hydrothermal treatment temperature on the type of zeolite formed. The surface morphology and composition of prepared zeolite was characterized by SEM-EDS while the type of zeolite was determined by XRD analysis. Preliminary study of the adsorption ability of the zeolites towards metal ions was carried out by CEC measurement using sodium acetate method.


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