Surface Modification of Cellulose from Sugarcane Bagasse Using Soybean Oil to Increase the Hydrophobicity

Cellulose fibers from sugarcane bagasse were bleached and modified by soybean oil in order to increase the hydrophobicity. The modified cellulose prepared by mising cellulose fibers with soybean oil in various quantity and ethanol as a solvent. the process was mixed using ultrasonic for 3 minutes and than was dried using oven at 110 oC for 60 minutes. Identification of the infrared spectrum confirmed that cellulose modified by 0,35 g and 0,5 g soybean oil generates signals carbonyl functional group at wavenumber 1750 cm-1. The XRD patterns indicated that degree of crystalinity from modified cellulose did not change significantly. In addition, the wettability test showed that the modified cellulose hard to dispersed in water solvent

Surface Modification of Cellulose from Sugarcane Bagasse Using Soybean Oil to Increase the Hydrophobicity

Cellulose fibers from sugarcane bagasse were bleached and modified by soybean oil in order to increase the hydrophobicity. The modified cellulose prepared by mising cellulose fibers with soybean oil in various quantity and ethanol as a solvent. the process was mixed using ultrasonic for 3 minutes and than was dried using oven at 110 oC for 60 minutes. Identification of the infrared spectrum confirmed that cellulose modified by 0,35 g and 0,5 g soybean oil generates signals carbonyl functional group at wavenumber 1750 cm-1. The XRD patterns indicated that degree of crystalinity from modified cellulose did not change significantly. In addition, the wettability test showed that the modified cellulose hard to dispersed in water solvent

Simultaneous Analysis of Dopamine and Ascorbic Acid Using Polymelamine/Gold Nanoparticle-Modified Carbon Paste Electrode

Modification of electrode using polymelamine (PM) and gold nanoparticles (AuNPs) has been successfully developed via electropolymerization and electrodeposition onto carbon paste electrode (CPE) using cyclic voltammetry (CV) technique. The modified electrode (AuNPs/PM/CPE) was applied as voltammetry sensors in a simultaneous of dopamine (DA) and ascorbic acid (AA). AuNPs/PM/CPE presented an effective surface area 5 times wider than CPE and demonstrated good electrocatalytic performance in the oxidation of DA and AA in 0.1 M phosphate buffer solution (pH 3) with a scan rate of 100 mV s−1. The differential pulse voltammetry (DPV) technique was chosen as the best method for separating potential peaks of DA and AA. The linear response for determining DA and AA using the DPV technique produced a concentration range of 0.1–13 and 0.4–12 µM with coefficient linearity of 0.9999 and 0.9997, the limit of detection of 0.1405 and 0.2187 µM, the accuracy of 89.62–109.16%, and 83.63–105.08%, and the precision of 0.017–0.701% and 0.066–0.626%, respectively. In addition, this electrode was applied in a real sample of infant urine with a concentration of 1 µM by spike method and found 98.86 and 98.28% as percent recovery of DA and AA, respectively

Cyclopropanation of Various Substrates via Simmons-Smith and Michael-Initiated Ring Closure (MIRC) Reactions

Cyclopropanation of various electron rich and electron deficient olefins via Simmons-Smith and Michael-initiated ring closure reactions was studied in our research. Cinnamyl alcohol 18 was succesfully cyclopropanated in a good to excellent yield using Simmons-Smith reactions. Methyl and benzyl crotonate 14 and 16 were labile in MIRC reaction condition indicated by the detection of starting material degradation in the NMR spectra of the crude reactions, and allowed a low to moderate product yield. The other starting materials, i.e., cinnamaldehyde 19, methyl cinnamate 20, mono- and di-protected cross-coupled product (4R,5R,E)-methyl 5-(tert-butyldimethylsilyloxy)-4-hydroxyhepta-2,6-dienoate 25 and (4R,5R,E)-methyl 5-(tert-butyldimethylsilyloxy)-4-(methoxymethoxy)hepta-2,6-dienoate 26, were apparently incompatible to the reaction condition set in our study

Asymmetric Synthesis of (−)-Brevipolide H through Cyclopropanation of the α,β-Unsaturated Ketone

Brevipolides are 5,6-dihydro-γ-pyrone derivatives, first reported in 2004 as the inhibitors of the chemokine receptor CCR5 and exhibiting cytotoxicity against cancer cells. Starting from the <i>C</i>₂ symmetric diene-diol <b>2</b>, <i>ent</i>-brevipolide H was synthesized for the first time in 11 steps. The <i>anti</i>-addition of the sulfur ylide to the α,β-unsaturated enones was developed to give the key cyclopropane moiety. The synthetic (−)-brevipolide H showed an IC₅₀ value of 7.7 μM against PC-3 cells