Synthesis and characterization of camphorsulfonyl acetate of cellulose

Fabrication of Cellulose Acetate-Based Proton Exchange Membrane with Sulfonated SiO2 and Plasticizers for Microbial Fuel Cell Applications

Developing a hybrid composite polymer membrane with desired functional and intrinsic properties has gained significant consideration in the fabrication of proton exchange membranes for microbial fuel cell applications. Among the different polymers, a naturally derived cellulose biopolymer has excellent benefits over synthetic polymers derived from petrochemical byproducts. However, the inferior physicochemical, thermal, and mechanical properties of biopolymers limit their benefits. In this study, we developed a new hybrid polymer composite of a semi-synthetic cellulose acetate (CA) polymer derivate incorporated with inorganic silica (SiO₂) nanoparticles, with or without a sulfonation (-SO₃H) functional group (sSiO₂). The excellent composite membrane formation was further improved by adding a plasticizer (glycerol (G)) and optimized by varying the SiO₂ concentration in the polymer membrane matrix. The composite membrane's effectively improved physicochemical properties (water uptake, swelling ratio, proton conductivity, and ion exchange capacity) were identified because of the intramolecular bonding between the cellulose acetate, SiO₂, and plasticizer. The proton (H⁺) transfer properties were exhibited in the composite membrane by incorporating sSiO₂. The composite CAG-2% sSiO₂ membrane exhibited a higher proton conductivity (6.4 mS/cm) than the pristine CA membrane. The homogeneous incorporation of SiO₂ inorganic additives in the polymer matrix provided excellent mechanical properties. Due to the enhancement of the physicochemical, thermal, and mechanical properties, CAG-sSiO₂ can effectively be considered an eco-friendly, low-cost, and efficient proton exchange membrane for enhancing MFC performance.

The determination of enantiomer composition of 1-((3-chlorophenyl)-(phenyl)methyl) amine and 1-((3-chlorophenyl)(phenyl)-methyl) urea (Galodif) by NMR spectroscopy, chiral HPLC, and polarimetry

For the first time, a method for enantiomer resolution of the anticonvulsant Galodif (1-((3-chlorophenyl)(phenyl)methyl) urea) by chiral HPLC was developed, whereas the enantiomeric composition of 1-((3-chlorophenyl)(phenyl)methyl) amine-precursor in Galodif synthesis-cannot be resolved by this method. However, starting 1-((3-chlorophenyl)(phenyl)methyl) amine quantitatively forms diastereomeric N-((3-chlorophenyl)(phenyl)methyl)-1-camphorsulfonamides in reaction with chiral (1R)-(+)- or (1S)-(-)-camphor-10-sulfonyl chlorides. The diastereomeric ratio of obtained camphorsulfonamides can be easily determined by NMR ¹ H and ¹³ C spectroscopy. The DFT calculations of specific rotation of Galodif enantiomers showed good agreement with experimental data. The absolute configuration of enantiomers was proposed for the first time.

Reactive Black 5 dye degradation using filters of smuggled cigarette modified with Fe3

This study presents an attempt to solve two serious environmental problems: the generation of toxic effluents and solid waste disposal. The work proposes recycling cigarette filters with the purpose of degrading reactive dyes, which are used in the textile industry. Filters of smuggled cigarettes were recycled through Fe³⁺ immobilization on their surface. The material obtained was characterized through Fourier transform infrared spectroscopy (FTIR), atomic absorption spectroscopy (AAS), scanning electron microscopy-energy-dispersive spectroscopy (SEM-EDS), and ultraviolet-visible spectroscopy (UV-vis). The factorial design revealed that the most suitable conditions for the degradation of Reactive Black 5 dye were obtained by using 1 g of material at pH 3.0 in a 100 mg L^-1 hydrogen peroxide solution. The material showed excellent performance in the Reactive Black 5 dye degradation process; in 60 min, 99.09 % dye was removed. At pH 7.0, the dye degradation was 72.67 %, indicating that the material prepared can be used at pH values greater than 3.0 without the occurrence of hydrated Fe³⁺ oxide precipitation. Furthermore, the material showed no loss of catalytic activity after three degradation studies.

Preparation and application of cellulose acetate/Fe films in the degradation of Reactive Black 5 dye through photo-Fenton reaction

In this study, the Reactive Black 5 dye degradation and textile effluent were investigated using the photo-Fenton process employing immobilized Fe(3+) in acetate cellulose films. The films prepared were characterized through Fourier transform infrared spectroscopy, atomic absorption spectroscopy, scanning electron microscopy - energy-dispersive spectroscopy and ultraviolet visible spectroscopy. The factorial design revealed that the best conditions for the Reactive Black 5 dye degradation were obtained using the film containing 5% Fe (w/w), 100 mg L(-1) H2O2 and pH 4.0. In studies using artificial light, the dye degradation was 99.29% and the chemical oxygen demand (COD) reduction was 90% after 45 min of treatment. In the process assisted by sunlight, the degradation was 86% and the COD reduction was 70% considering the same time of treatment. At pH 6.0 and artificial light, the dye degradation was 98.90% and the COD reduction was 78%, indicating that the material prepared can be used at pH values greater than 3 without the occurrence of hydrated ferric oxides precipitation. It was also observed that the material can be reused seven consecutive times without substantial loss of efficacy in dye degradation. Furthermore, the proposed material reduces the COD of a textile effluent by 72% after 300 min of treatment.