Synthesis and biological activities of endo-3,6-epoxy-1,2,3,6-tetrahydrophthalimide and its polymers

Photocopolymerizations of endo-3,6-epoxy-1,2,3,6-tetrahydrophthalimide (ETPI) with acrylic acid (AA), vinyl acetate (VAc), and maleic anhydride (MAH) were carried out in a mixed solvent of 2-butanone and acetone using 2,2-dimethoxy-2-phenylacetophenone as an initiator at 25°C. Synthesized ETPI, poly(ETPI), poly(ETPI-co-AA), poly(ETPI-co-VAc), and poly(ETPI-co-MAH) were characterized by IR and ¹H-NMR spectroscopies, elemental analysis, and gel permeation chromatography. The synthesized polymers have a number-average molecular weight (M_n) in the range of 3500-27,400. The in vitro cytotoxicities of poly(ETPI), poly(ETPI-co-AA), poly(ETPI-co-VAc), and poly(ETPI-co-MAH) against fibroblast and K-562 human leukemia cells were lower than that of monomeric ETPI at a low concentration (0.02 mg/mL). The in vivo antitumor activities of the polymers were evaluated by the survival time with sarcoma 180 tumor-bearing mice. The polymers showed higher antitumor activity and lower toxicity than both monomeric ETPI and 5-fluorouracil at all doses tested. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 2605–2612, 1997     

Hydrogen production from waste activated sludge by using separation membrane acid fermentation reactor and photosynthetic reactor

The possibility and characteristics of hydrogen production from waste activated sludge were investigated using separation membrane acid fermentation reactor (AR) and photosynthetic reactor (PR). The AR used submerged and external separation membranes and it was followed by the PR. The COD removal efficiencies in the AR with submerged and external separation membrane were about 65% and 40%, respectively. More VFA was produced in the AR with external separation membrane than AR with submerged separation membrane. Hydrogen was produced in the PR but not in the AR and hydrogen productions in the PR connected with submerged membrane AR and external membrane AR were about 50.1 and 160.5 ml _H2/g${\mathrm{H}}_2/\mathrm{g}$ T-VFA, respectively.     

Solution-processed highly adhesive graphene coatings for corrosion inhibition of metals

Nano Research - The corrosion of metals can be induced by different environmental and operational conditions, and protecting metals from corrosion is a serious concern in many applications. The...     

Effect of COD/SO4ratio and Fe(II) under the variable hydraulic retention time (HRT) on fermentative hydrogen production

The effect of chemical oxygen demand/sulfate (COD/SO₄²⁻) ratio on fermentative hydrogen production using enriched mixed microflora has been studied. The chemostat system maintained with a substrate (glucose) concentration of 15 g COD L⁻¹ exhibited stable H₂ production at inlet sulfate concentrations of 0-20 g L⁻¹ during 282 days. The tested COD/SO₄²⁻ ratios ranged from 150 to 0.75 (with control) at pH 5.5 with hydraulic retention time (HRT) of 24, 12 and 6 h. The hydrogen production at HRT 6 h and pH 5.5 was not influenced by decreasing the COD/SO₄²⁻ ratio from 150 to 15 (with control) followed by noticeable increase at COD/SO₄²⁻ ratios of 5 and 3, but it was slightly decreased when the COD/SO₄²⁻ ratio further decreased to 1.5 and 0.75. These results indicate that high sulfate concentrations (up to 20,000 mg L⁻¹) would not interfere with hydrogen production under the investigated experimental conditions. Maximum hydrogen production was 2.95, 4.60 and 9.40 L day⁻¹ with hydrogen yields of 2.0, 1.8 and 1.6 mol H₂ mol⁻¹ glucose at HRTs of 24, 12 and 6 h, respectively. The volatile fatty acid (VFA) fraction produced during the reaction was in the order of butyrate > acetate > ethanol > propionate in all experiments. Fluorescence In Situ Hybridization (FISH) analysis indicated the presence of Clostridium spp., Clostridium butyricum, Clostridium perfringens and Ruminococcus flavefaciens as hydrogen producing bacteria (HPB) and absence of sulfate reducing bacteria (SRB) in our study.