Synthesis and Characterization of β-Cyclodextrin Microspheres with Temperature and pH Sensibility

2012 ◽  
Vol 583 ◽  
pp. 391-394 ◽  
Author(s):  
Qiang Zhang ◽  
Li Qin You ◽  
Chun Shan Zhu
Keyword(s):  
Phase Transition ◽  
Grain Size ◽  
Succinic Anhydride ◽  
Ph Value ◽  
Synthesis And Characterization ◽  
Ph Values ◽  
Swelling Rate

The β-CD/NIPAAm-SA microspheres with temperature and pH sensibility were synthesized with β-cyclodextrin(β-CD), N-isopropylacrylamide(NIPAAm) and succinic anhydride(SA), and their drug-releasing properties were investigated. SEM showed that the β-CD/NIPAAm-SA microspheres had a good sphericity and a grain size of 200-300µm.And the swelling results indicated that the swelling rate was decreased with temperature raising and increased with pH value improving, and the phase transition volume changed suddenly at the temperature of about 27°C and 38°C, and the pH values of about 1.4 and 7.4. It revealed that the β-CD/NIPAAm-SA microspheres had pH and temperature sensibilities.

scholarly journals Graphene Oxide/Fe-Based Composite Pre-Polymerized Coagulants: Synthesis, Characterization, and Potential Application in Water Treatment

2020 ◽  
Vol 6 (3) ◽  
pp. 44
Author(s):  
Athanasia K. Tolkou ◽  
Anastasios I. Zouboulis
Keyword(s):  
Graphene Oxide ◽  
Surface Water ◽  
Ph Value ◽  
Synthesis And Characterization ◽  
Alkaline Ph ◽  
Sem Images ◽  
Operational Conditions ◽  
Ph Values ◽  
First Time

This study presents for the first time the synthesis and characterization of GO (graphene oxide), PFSiC (polyferric silicate chloride), and hybrid GO-PFSiC derivatives, aiming to enhance synergistically the performance of coagulation, when applied for the treatment of water. The structure and the morphology of composite GO-PFSiC coagulants were studied in detail by the application of FTIR, XRD, and SEM characterization techniques. Furthermore, the proposed coagulants were applied for the treatment of simulated turbid surface water. The effects of the reagent’s dosage, pH value, and experimental/operational conditions on the coagulation efficiency, applied mainly for the removal of turbidity, were examined. The results, obtained from the FTIR and XRD measurements, showed the presence of a bond between the PFSiC and the GO surface, indicating that the PFSiC particles are distributed uniformly on the surface of graphene, which was also confirmed by the SEM images. Especially, the composite compound GO-PFSiC1.5-15-0.5 presents the most uniform distribution of iron on the surface of graphene oxide and exhibits the optimum coagulation efficiency, while it significantly reduces the turbidity for doses above 3–5 mg/L, i.e., achieving the respective legislation limit as proposed by WHO. Specifically, at the alkaline pH values (>7.9), the removal of turbidity reaches 96%. Consequently, the results of this study render these materials as potential coagulant agents for further research and applications, aiming to also achieve the co-removal of other water components.

Synthesis and order–disorder transition in a novel metal formate framework of [(CH3)2NH2]Na0.5Fe0.5(HCOO)3]

2014 ◽  
Vol 43 (45) ◽  
pp. 17075-17084 ◽  
Author(s):  
Mirosław Mączka ◽  
Adam Pietraszko ◽  
Lucyna Macalik ◽  
Adam Sieradzki ◽  
Justyna Trzmiel ◽  
...  
Keyword(s):  
Phase Transition ◽  
Synthesis And Characterization ◽  
Disorder Transition ◽  
Metal Formate

We report the synthesis and characterization of a novel metal formate templated by dimethylammonium cations, [(CH3)2NH2][Na0.5Fe0.5(HCOO)3], exhibiting phase transition at 167 K.

Synthesis and characterization of CO2-sensitive temperature-responsive catalytic poly(ionic liquid) microgels

2018 ◽  
Vol 9 (21) ◽  
pp. 2887-2896 ◽  
Author(s):  
Shoumin Chen ◽  
Xuezhen Lin ◽  
Zhenghao Zhai ◽  
Ruyue Lan ◽  
Jin Li ◽  
...  
Keyword(s):  
Phase Transition ◽  
Ionic Liquid ◽  
Synthesis And Characterization ◽  
Volume Phase Transition ◽  
Phase Transition Behavior ◽  
Volume Phase ◽  
Temperature Responsive ◽  
Transition Behavior ◽  
Poly Ionic Liquid

A class of poly(ionic liquid) microgels exhibiting CO2-switchable temperature-responsive volume phase transition behavior have been synthesized and used for CO2 fixation.

Effect of pH value on the synthesis and characterization of Ba0.5Sr0.5Co0.8Fe0.2O3−δ powders prepared by the citrate–EDTA complexing method

2010 ◽  
Vol 45 (14) ◽  
pp. 3824-3832 ◽  
Author(s):  
I.-Ming Hung ◽  
Chen-Yu Liang ◽  
Chun-Jing Ciou ◽  
Ren-Zheng Song ◽  
Zu-Yu Lai
Keyword(s):  
Ph Value ◽  
Synthesis And Characterization ◽  
Effect Of Ph

Synthesis and Characterization of BaCe0.8Y0.2O2.9 Nanopowder by Sol-Gel Auto-Ignited Method

2007 ◽  
Vol 280-283 ◽  
pp. 661-664 ◽  
Author(s):  
Jing Tao Ma ◽  
Xu Ping Lin ◽  
Bao Qing Zhang ◽  
Jiu Lin Wang
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Ph Value ◽  
Sol Gel ◽  
Ceramic Powder ◽  
Solid Oxide ◽  
Synthesis And Characterization ◽  
Nanocrystalline Ceramic ◽  
Optimal Ph ◽  
Nitrate Solutions

A sol-gel auto-ignited synthesis, which is a hybrid of sol-gel and auto-ignited techniques, was applied to preparation of homogeneous and stoichiometric BaCe0.8Y0.2O2.9 nanocrystalline ceramic powder as solid electrolyte used in solid oxide fuel cells at 1000°C. Optimal pH value for the mixed citrate-nitrate solutions was determined by calculation. The DTA-TG and XRD were used to investigate the thermal decomposition of the gel precursor. The structure and phase present of the nanocrystalline BaCe0.8Y0.2O2.9 powders were characterized by XRD, BET and SEM techniques.

Synthesis and Characterization of Nano-Calcium Titanate-Based Coated Aluminum Oxide and its Application in Water Analysis of Cr(III) and Cr(VI) Concentration

2010 ◽  
Vol 44-47 ◽  
pp. 2136-2139
Author(s):  
Dong Zhang
Keyword(s):  
Aluminum Oxide ◽  
Sol Gel ◽  
Calcium Titanate ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Composite Adsorbent ◽  
X Ray ◽  
Ph Values ◽  
Adsorption Capability

Nano-calcium titanate-based coated aluminum oxide (ACCTO) was successfully prepared by the citrate acid sol-gel method and characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Its application in speciation of Cr(III) and Cr(VI) from water was studied. The conditions of adsorption and elution were investigated. The results show that nanometer calcium titanate could be immobilized on the aluminum oxide firmly, becoming a composite adsorbent. Two forms of chromium showed different adsorption capability at different pH values, Cr (III) selectively retained at pH 8-14, whereas Cr (VI) retained at pH≤2. So separation of the Cr(III) and Cr(VI) is possible. Retained species were eluted with 5mL of 1 mol•L-1 HCl and NaOH. The Cr(III) and Cr(VI) concentration was measured by atomic absorption spectroscopy. The adsorption agent has a promising prospect in removal or enriching and separation of Cr(III) and Cr(VI) in water.

Synthesis and Characterization of Carboxyl-Terminated Hyperbranched Polyester

2014 ◽  
Vol 665 ◽  
pp. 327-330
Author(s):  
Shi Jie Niu ◽  
Jian Wang ◽  
Yu Qing Bai ◽  
Ming Tao Run
Keyword(s):  
Glass Transition ◽  
Sodium Acetate ◽  
Succinic Anhydride ◽  
Molar Ratio ◽  
Synthesis And Characterization ◽  
Hydroxyl Groups ◽  
Hyperbranched Polyester ◽  
End Groups ◽  
Lower Glass Transition Temperature

In order to prepare carboxyl-terminated hyperbranched polyester (HBP-COOH), succinic anhydride was used to modify hydroxyl-terminated hyperbranched polyester (HBP-OH), and the influences of the solvents, catalysts and time on the product’s structure were investigated. When THF is used as the solvent, sodium acetate as the catalyst, the molar ratio of succinic anhydride and hydroxyl groups is 3:1, and the reaction time is 6 h at 65°C, the modification extent of the hydroxyl groups is about 99% with about 95% yield. HBP-COOH has much lower glass transition temperature than that of HBP-OH due to its long and flexible end-groups.

Sign in / Sign up

Export Citation Format

Share Document