Formation of BaF2 Microcrystals as Superhydrophobic Materials via a Hydrothermal Method

Author(s):  
Jinxiu Ma ◽  
Gaoyu Ou ◽  
Taohai Li ◽  
Feng Li

Abstract Controllable BaF2 microcrystals with super-hydrophobic property have been successfully synthesized via a facile hydrothermal process. XRD, SEM and CA are used to study the structure, morphology and the hydrophobic properties of the BaF2 materials. The effects of reaction time, surfactants and pH are also detailed investigated in order to get a series of accurate reaction conditions for the preparation of BaF2 material. The results show that uniform BaF2 tetragonal phase structure was fabricated when the reaction temperature was controlled at 180 oC for 24 h. In addition, the BaF2 materials showed excellent super-hydrophobic properties. The results about the influence of time and substrates exhibit that the sample can maintain the stable super-hydrophobic property for over 10 days. As a promising super hydrophobic materials, the studies of BaF2 reported in this paper is quite practical and it has a certain guiding meaning for the future study about super hydrophobic materials.

2013 ◽  
Vol 423-426 ◽  
pp. 550-553 ◽  
Author(s):  
Bing Jiang ◽  
Wen Qin Wang ◽  
Yu Song Liu ◽  
Zhi Meng Guo

FePO4·2H2O with orthorhombic flower-like microstructure was synthesized by a facile hydrothermal process which was of low-cost and easy processing in large area. The formation mechanism of the flower-like FePO4·2H2O was discussed in details by investigating the different concentration of reactants and reaction time. The results show that the morphology of FePO4·2H2O changed from microsphere to flower-like structure, which possess an unique morphology with six petals and the angle of each petal being 60o. The formation mechanism of FePO4·2H2O flowers can be explained by the dissolution-recrystallization and crystal splitting.


Holzforschung ◽  
2016 ◽  
Vol 70 (5) ◽  
pp. 421-427 ◽  
Author(s):  
Giridhar B. Nagarajappa ◽  
Krishna K. Pandey ◽  
Aniket S. Shinde ◽  
Hosadu M. Vagdevi

Abstract Solvent-free acetylation of rubberwood (Hevea brasiliensis Müll.Arg) with acetic anhydride (Ac2O) and by means of N-bromosuccinimide (NBS) as catalyst was carried out in an oil bath at 105°C and 120°C. The effect of catalyst concentration, temperature, and reaction time was studied. The extent of acetylation was measured by determining the weight percent gain (WPG), and the acetylated wood was characterized by FTIR-ATR, CP/MAS 13C NMR, and XRD spectroscopy. The presence of NBS in concentrations between 1.0% and 3.0% elevated the acetylation rate to a great extent. WPG increased from 8.1% without catalyst to 22.1% for 2% NBS concentration after 60 min reaction at 120°C. Similarly, after 60-min reaction time at 105°C, WPG with 3% NBS concentration was 19.0% compared to 7.6% with un-catalyzed reaction under the same reaction conditions. The effect of microwave heating (MWh) on the NBS-catalyzed acetylation was also investigated. A significant level of modification was achieved within a few minutes of MWh. The hydrophobic properties and dimensional stability of the acetylated wood were elevated. NBS was found to be an effective catalyst for wood acetylation.


2011 ◽  
Vol 396-398 ◽  
pp. 2411-2415 ◽  
Author(s):  
Ping Lan ◽  
Li Hong Lan ◽  
Tao Xie ◽  
An Ping Liao

Isoamyl acetate was synthesized from isoamylol and glacial acetic acid with strong acidic cation exchanger as catalyst. The effects of reaction conditions such as acid-alcohol ratio, reaction time, catalyst dosage to esterification reaction have been investigated and the optimum reaction conditions can be concluded as: the molar ratio of acetic acid to isoamylol 0.8:1, reaction time 2h, 25 % of catalyst (quality of acetic acid as benchmark). The conversion rate can reach up to 75.46%. The catalytic ability didn’t reduce significantly after reusing 10 times and the results showed that the catalyst exhibited preferably catalytic activity and reusability.


2012 ◽  
Vol 627 ◽  
pp. 378-381
Author(s):  
Bi Rong Wang

Fenton pretreatment has been used for treating dye wastewater. The effects of the dos of H2O2 and FeSO4, reaction time and pH on the removal COD were investigated. It was found that, when the reaction conditions are as follows: COD 2850 mg/L dyeing wastewater, the dosage of H2O2 is 140mmol/L, FeSO4 17.02 mmol/L, pH 7.6, and reaction time 1.0 h, the CODcr of dye wastewater removal rate of up to 70%. Fenton pretreatment process of dye wastewater has a broad prospect.


2011 ◽  
Vol 17 (3) ◽  
pp. 323-331 ◽  
Author(s):  
Jiancheng Zhou ◽  
Wu Dongfang ◽  
Birong Zhang ◽  
Yali Guo

A series of single-metal carbonates and Pb-Zn mixed-metal carbonates were prepared as catalysts for alcoholysis of urea with 1,2-propylene glycol (PG) for the synthesis of propylene carbonate (PC). The mixed carbonates all show much better catalytic activities than the single carbonates, arising from a strong synergistic effect between the two crystalline phases, hydrozincite and lead carbonate. The mixed carbonate with Pb/Zn=1:2 gives the highest yield of PC, followed by the mixed carbonate with Pb/Zn=1:3. Furthermore, Taguchi method was used to optimize the synthetic process for improving the yield of PC. It is shown that the reaction temperature is the most significant factor affecting the yield of PC, followed by the reaction time, and that the optimal reaction conditions are the reaction time at 5 hours, the reaction temperature at 180 oC and the catalyst amount at 1.8 wt%, resulting in the highest PC yield of 96.3%.


2017 ◽  
Vol 41 (2) ◽  
pp. 88-92
Author(s):  
Shenggui Liu ◽  
Rongkai Pan ◽  
Wenyi Su ◽  
Guobi Li ◽  
Chunlin Ni

2,6-Bis[1-(pyridin-2-yl)-1H-benzo[d]-imidazol-2-yl]pyridine (bpbp), which has been synthesised by intramolecular thermocyclisation of N2,N6-bis[2-(pyridin-2-ylamino)phenyl]pyridine-2,6-dicarboxamide, reacts with sodium pyridine-2,6-dicarboxylate (pydic) and RuCl3 to give [Ru(bpbp)(pydic)] which can catalyse the oxidation of (1H-benzo[d]imidazol-2-yl)methanol to 1H-benzo[d]imidazole-2-carbaldehyde by H2O2. The optimal reaction conditions were: molar ratios of catalyst to substrate to H2O2 set at 1: 1000: 3000; reaction temperature 50 °C; reaction time 5 h. The yield of (1H-benzo[d]imidazol-2-yl) methanol was 70%.


Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2562 ◽  
Author(s):  
Chia-Hung Su ◽  
Hoang Nguyen ◽  
Uyen Pham ◽  
My Nguyen ◽  
Horng-Yi Juan

This study investigated the optimal reaction conditions for biodiesel production from soursop (Annona muricata) seeds. A high oil yield of 29.6% (w/w) could be obtained from soursop seeds. Oil extracted from soursop seeds was then converted into biodiesel through two-step transesterification process. A highest biodiesel yield of 97.02% was achieved under optimal acid-catalyzed esterification conditions (temperature: 65 °C, 1% H2SO4, reaction time: 90 min, and a methanol:oil molar ratio: 10:1) and optimal alkali-catalyzed transesterification conditions (temperature: 65 °C, reaction time: 30 min, 0.6% NaOH, and a methanol:oil molar ratio: 8:1). The properties of soursop biodiesel were determined and most were found to meet the European standard EN 14214 and American Society for Testing and Materials standard D6751. This study suggests that soursop seed oil is a promising biodiesel feedstock and that soursop biodiesel is a viable alternative to petrodiesel.


CrystEngComm ◽  
2016 ◽  
Vol 18 (7) ◽  
pp. 1090-1095 ◽  
Author(s):  
Xueyu Zhang ◽  
Xin Ge ◽  
Shihan Sun ◽  
Yuanduo Qu ◽  
Wenzhong Chi ◽  
...  

This paper investigated the preparation of 3D RGO/CdS hydrogels by a facile hydrothermal process, the morphology control of CdS (ball-like, rod-like, needle-like) in 3D structures, and their application in electrochemical energy storage.


2018 ◽  
Vol 25 (1) ◽  
pp. 23-30
Author(s):  
Chengjin Zhang ◽  
Shaoyi Jia ◽  
Songhai Wu ◽  
Yong Liu

2019 ◽  
pp. 1232-1239
Author(s):  
Mohammed A Alsoufi ◽  
Raghad A. Aziz

The aim of this study was the production of aspartame by using immobilized thermolysin in bentonite clay. The yield of immobilized thermolysin in bentonite was 92% of the original enzyme amount. pH profile of free and immobilized enzyme was 7.0 and 7.5 respectively which was stable at 6.5-9.0 for 30min. The optimum temperature of both enzymes was 50°C, while they were stable at 65°C for 30min. however, they lost 52.73 and 61.72% from its main activity at 80°C respectively. Immobilized thermolysin has retained all activity within 27 days, but it kept 68.27% of initial activity when stored for 60 days at 4°C whereas, it retained a full activity after 20 continue usage. In addition, it retained 86.53% of its original activity after 30 continuing usages. The yield of produced aspartame was increased with reaction time; it was 9% after 1h and increased gradually to 100% after 10h at reaction conditions.


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