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KOVALEN ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 208-213
Author(s):  
Mukhtar Ghozali ◽  
Gamaliel Tanaka ◽  
Muhammad Misbahussalam ◽  
Tifa Paramitha

ZSM-5 is a synthetic zeolite which has a complex production process and is affected by operating conditions, such as temperature and time. In this study, synthesized ZSM-5 without template by hydrothermal method. An autoclave reactor was used for the hydrothermal process. The aim of this study was to investigate the effect of varied hydrothermal times of 24 and 48 hours with a hydrothermal temperature of 180oC on the characteristic of ZSM-5. The raw materials used were silica oxide and aluminum hydroxide as a source of silica and alumina. The synthesis results were characterized using X-Ray Diffraction (XRD). Based on XRD results, the best result was obtained in performed at 48 hours hydrothermal time indicating the formation of ZSM-5 material at the 22.2o position. The percentage crystallinity of the sample at the hydrothermal time of 48 hours was 51.3%.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Sheng Chen ◽  
Liping Qiu ◽  
Shaofang Sun ◽  
Junyi Yang ◽  
Qinghua Meng ◽  
...  

The deep sea is the frontier of materials research in the 21st century. Owing to the particularity of pressure (15–120 MPa), hydrothermal temperature (90–400°C), and explosive fluid (strong H2S) in the deep-sea hydrothermal field environment, the research on the corrosion mechanism of service materials in this environment under the coupling action of many harsh factors is almost blank. It has become the bottleneck of equipment and material research and development for China to explore the deep sea. This paper reviews the research progress of corrosion mechanisms of deep-sea environmental materials at home and abroad, and forecasts the research trend and difficulties in this field, especially in the deep-sea hydrothermal field. At the same time, it points out the urgency of the construction of harsh environment materials platform and its relevance to the discipline construction of marine college.


2021 ◽  
Author(s):  
Yaoxin LIU ◽  
Enyu Wang ◽  
Ze KAN

Abstract Under the pressure of environmental problems and fossil energy shortage, countries all over the world are looking for fuel to replace fossil energy. Oil shale and rice husk are potential fuels, but they both have some problems, such as high ash content and low calorific value .In the present study,oil shale and rice husk were used as feedstock for the high quality fuel through hydrothermal approach,it provides a new way for the resource utilization of oil shale and rice.Thermogravimetric method was used to analyze the functional groups change and thermal transformation characteristics of mixed hydrochars prepared for oil shale(OS) and rice husk(RH) at different hydrothermal temperatures(150,200 and 250℃), including combustion and pyrolysis processes, and analyze the synergistic effects. Results showed that the co-hydrocharsization pretreatment had a significant effect on the thermal transformation behavior of oil shale and rice husk.On the one hand, the mixture of hydrocar has higher volatile content than its calculated value.On the other hand,a synergistic effect(promoting combustion and pyrolysis behavior) was found in both combustion and pyrolysis processes, and this effect was the most obvious when the hydrothermal temperature was around 200℃,and the characteristic peak of functional groups vibration was strong.Since the synergistic effect of pyrolysis process is lower than that of combustion process, co-hydrocharsation products are considered to be more suitable for combustion.These findings have positive significance of energy generation and utilization of organic waste by the combination of co-hydrocharsization modification and subsequent thermochemical process.


2021 ◽  
Vol 10 (5) ◽  
pp. 1095-1106
Author(s):  
Weiye Liu ◽  
Rongtai Zuo ◽  
Tanglong Zhu ◽  
Min Zhu ◽  
Shichang Zhao ◽  
...  

AbstractBone engineering scaffolds with antibacterial activity satisfy the repair of bacterial infected bone defects, which is an expected issue in clinical. In this work, 3D-printed polymer-derived forsterite scaffolds were proposed to be deposited with hydroxyapatite (HA) coating via a hydrothermal treatment, achieving the functions of photothermal-induced antibacterial ability and bioactivity. The results showed that polymer-derived forsterite scaffolds possessed the photothermal antibacterial ability to inhibit Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) in vitro, owing to the photothermal effect of free carbon embedded in the scaffolds. The morphology of HA coating on forsterite scaffolds could be controlled through changing the hydrothermal temperature and the pH value of the reaction solution during hydrothermal treatment. Furthermore, HA coating did not influence the mechanical strength and photothermal effect of the scaffolds, but facilitated the proliferation and osteogenic differentiation of rat bone mesenchymal stem cells (rBMSCs) on scaffolds. Hence, the HA-deposited forsterite scaffolds would be greatly promising for repairing bacterial infected bone defects.


2021 ◽  
Vol 11 (1) ◽  
pp. 74-79
Author(s):  
Linh Nguyen Le My ◽  
Hieu Bach Thi Kim

In this paper, CuO nanosheets were successfully synthesized by a simple hydrothermal method. The synthesized CuO nanosheets were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR), surface area analysis (BET). Several factors influencing the synthesis of material such as concentration of NaOH, hydrothermal temperature and hydrothermal time were studied. Scanning electron microscopy (SEM) investigation reveals that CuO nanosheets have the length of about 500 - 1000 nm. N2 adsorption–desorption isotherm experiment shows that the BET specific surface area of obtained CuO nanosheets is 12.78 m2/g.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Thi Thuy Trang Phan ◽  
Thi Thanh Huong Nguyen ◽  
Ha Tran Huu ◽  
Thanh Tam Truong ◽  
Le Tuan Nguyen ◽  
...  

MoS2/rGO composites were synthesized by hydrothermal method from the precursors of MoS2 and reduced graphene oxide (rGO) prepared in the former steps. The influence of the synthesis conditions including hydrothermal temperature and mass ratio of MoS2 to rGO on the structure, morphology, and optical absorption capacity of the MoS2/rGO composites was systematically investigated using physicochemical characterizations. The photocatalytic performance of as-prepared samples was investigated on the degradation of Rhodamine B under visible light, in which, the composites obtained at hydrothermal temperature of 180°C and MoS2/rGO mass ratio of 4/1 exhibited the highest photodegradation efficiency of approx. 80% after 4 hours of reaction. This enhancement in photocatalytic behaviour of composites could be assigned to the positive effect of rGO in life time expansion of photoinduced electrons—holes.


2021 ◽  
Vol 50 (6) ◽  
pp. 1685-1695
Author(s):  
Nurashina Abdul Rahman ◽  
Anita Ramli ◽  
Chong Fai Kait

In the present work, effect of hydrothermal temperature from 120 to 160 °C on TiO2 physicochemical properties as well as its photocatalytic activity towards biodiesel production using waste cooking oil (WCO) was investigated. TiO2was synthesized via hydrothermal method using Titanium butoxide, Ti(OBu)4 as the precursor and nitric acid, HNO3 as the peptizing agent. Next, the synthesized photocatalyst was dried at 60 °C for 24 h and later calcined at 400 °Cfor 2 h. The synthesized TiO2 was characterized using X-ray diffraction (XRD) and Burnauer- Emmet- Teller (BET) to determine their crystallinity and textural properties. Results showed that all synthesized TiO2 have a mixture of anatase and rutile phase and N2 adsorption- desorption isotherm for all catalyst possess Type IV isotherm according to IUPACclassification with hysteresis loop of type H1. Then, all the synthesized catalysts were tested for biodiesel production using esterified waste cooking oil under visible light irradiation for 1 h and 10 min. Percentage of fatty acid methyl ester (FAMEs) present in the synthesized biodiesel was determined using gas chromatography with flame ionization detector (GC-FID). The synthesized catalyst (T24_160) showed a good photocatalytic activity as the percentage of biodiesel yield was higher (3.41%) compared to the other catalyst.


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