scholarly journals Catalytic Activity for Decomposition of Hydrogen Peroxide by Metal Complexes of Water-Soluble Thiacalix[4]arenetetrasulfonate on the Modified Anion-Exchangers

2004 ◽  
Vol 52 (2) ◽  
pp. 266-269 ◽  
Author(s):  
Junichi Odo ◽  
Hanae Yamaguchi ◽  
Hirotaka Ohsaki ◽  
Noriyoshi Ohmura
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Metal Complexes ◽  
Water Soluble ◽  
Anion Exchangers

scholarly journals Catalytic Degradation of Chitosan by Supported Heteropoly Acids in Heterogeneous Systems

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1078
Author(s):  
Hang Zhang ◽  
Zhipeng Ma ◽  
Yunpeng Min ◽  
Huiru Wang ◽  
Ru Zhang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Molecular Weight ◽  
Catalytic Activity ◽  
Activated Carbon ◽  
Reaction Time ◽  
High Molecular Weight ◽  
Reaction Temperature ◽  
Water Soluble ◽  
High Catalytic Activity ◽  
High Molecular Weight Chitosan

Several kinds of composite materials with phosphotungstic acid (PTA) as the catalyst were prepared with activated carbon as support, and their structures were characterized. According to the Box–Behnken central combination principle, the mathematical model of the heterogeneous system is established. Based on the single-factor experiments, the reaction temperature, the reaction time, the amount of hydrogen peroxide and the loading capacity of PTA were selected as the influencing factors to study the catalyzed oxidation of hydrogen peroxide and degradation of high molecular weight chitosan. The results of IR showed that the catalyst had a Keggin structure. The results of the mercury intrusion test showed that the pore structure of the supported PTA catalyst did not change significantly, and with the increase of PTA loading, the porosity and pore volume decreased regularly, which indicated that PTA molecules had been absorbed and filled into the pore of activated carbon. The results of Response Surface Design (RSD) showed that the optimum reaction conditions of supported PTA catalysts for oxidative degradation of high molecular weight chitosan by hydrogen peroxide were as follows: reaction temperature was 70 ℃, reaction time was 3.0 h, the ratio of hydrogen peroxide to chitosan was 2.4 and the catalyst loading was 30%. Under these conditions, the yield and molecular weight of water-soluble chitosan were 62.8% and 1290 Da, respectively. The supported PTA catalyst maintained high catalytic activity after three reuses, which indicated that the supported PTA catalyst had excellent catalytic activity and stable performance compared with the PTA catalyst.

Chemoselective hydrogen peroxide oxidation of primary alcohols to aldehydes by a water-soluble and reusable iron(iii) catalyst in pure water at room temperature

2017 ◽  
Vol 41 (6) ◽  
pp. 2372-2377 ◽  
Author(s):  
Qi Yan ◽  
Ye Chen Fang ◽  
Yun Xue Jia ◽  
Xin Hong Duan
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Room Temperature ◽  
Pure Water ◽  
Water Soluble ◽  
High Catalytic Activity ◽  
Peroxide Oxidation ◽  
Primary Alcohols ◽  
Hydrogen Peroxide Oxidation

A novel, water-soluble and reusable FeCl3 catalyst showed high catalytic activity and chemoselectivity in the H2O2-oxidation of primary alcohols into aldehydes.

scholarly journals Catalytic Activity of Thiacalix[4]arenetetrasulfonate Metal Complexes on Modified Anion-Exchangers for Ascorbic Acid Oxidation

2013 ◽  
Vol 61 (9) ◽  
pp. 927-932 ◽  
Author(s):  
Junichi Odo ◽  
Tomomi Hirashima ◽  
Tomoko Hayashida ◽  
Asuka Miyauchi ◽  
Mami Minemoto ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Catalytic Activity ◽  
Metal Complexes ◽  
Acid Oxidation ◽  
Anion Exchangers

Neurotoxicity and Neuroprotective Effects of Polyimides (PI) and Polyphenylenevinylene (PPV) against Hydrogen Peroxide (H2O2)

2011 ◽  
Vol 8 (2) ◽  
pp. 33
Author(s):  
Norfaezah Mazalan ◽  
Mazatulikhma Mat Zain ◽  
Nor Saliyana Jumali ◽  
Norhanim Mohalid ◽  
Zurina Shaameri ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Drug Delivery Systems ◽  
Neuronal Cells ◽  
Water Soluble ◽  
Brain Delivery ◽  
Specific Therapy ◽  
Neuroprotective Effects ◽  
Water Soluble Polymer ◽  
Site Specific ◽  
Novel Drugs

Recently, research and development in the field of drug delivery systems (DDS) facilitating site-specific therapy has reached significant progression. DDS based on polymer micelles, coated micro- and nanoparticles, and various prodrug systems including water-soluble polymer have been prepared and extensively studied as novel drugs designed for cancer chemotherapy and brain delivery. Since polymers are going to be used in human, this study has the interest of testing two types of polymer, polyimides (PI) and polyphenylenevinylene (PPV) on neuronal cells. The objective of this study was to determine the possible neurotoxicity and potential neuroprotective effects of PI and PPV towards SH-SY5Y neuronal cells challenged by hydrogen peroxide (H2O2) as an oxidant. Cells were pretreated with either PI or PPV for 1 hour followed by incubation for 24 hour with 100 µM of H2O2. MTS assay was used to assess cell viability. Results show that PI and PPV are not harmful within the concentration up to 10 µM and 100 µM, respectively. However, PI and PPV do not protect neuronal cells against toxicity induced by H2O2 or further up the cell death.

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