Preparation of a carboxymethyl β-cyclodextrin polymer and its rapid adsorption performance for basic fuchsin

Decolorization enhancement of basic fuchsin by UV/H2O2 process: optimization and modeling using Box Behnken design

The present work deals with the optimization of basic fuchsin dye removal from an aqueous solution using the ultraviolet UV/H2O2 process. Response Surface Modeling (RSM) based on Box-Behnken experimental design (BBD) was applied as a tool for the optimization of operating conditions such as initial dye concentration (10-50 ppm), hydrogen peroxide dosage (H2O2) (10-20 mM/L) and irradiation time (60-180 min), at pH = 7.4 under ultra-violet irradiation (254 nm and 25 W intensity). Chemical oxygen demand (COD abatement) was used as a response variable. The Box-Behnken Design can be employed to develop a mathematical model for predicting UV/H2O2 performance for COD abatement. COD abatement is sensitive to the concentration of hydrogen peroxide and irradiation time. Statistical analyses indicate a high correlation between observed and predicted values (R2 > 0.98). In the BBD predictions, the optimal conditions in the UV/H2O2 process for removing 99.3% of COD were found to be low levels of pollutant concentration (10 ppm), a high concentration of hydrogen peroxide dosage (20 mM/L), and an irradiation time of 80 min.

Antibacterial drugs and cyclodextrin inclusion complexes: a patent review

INTRODUCTION

Bacterial antibiotic resistance occurs when bacteria mutate and escape the effect of antibiotics, which makes the antibiotics no longer effective in treating infections. New solutions for bacterial infections are a persistent need including the identification of drugs with better pharmacological profiles, more potent, and safer. Cyclodextrins inclusion complexes have been able to improve the physicochemical and pharmacological properties of the formulation molecules, resulting in new alternatives with better efficacy.

AREAS COVERED

The patents analyzed in the review used treatments based on antibiotics already on the market, natural products, and synthesized molecules composed of the formulation with cyclodextrins. The combination between cyclodextrin and nanostructures also were presented in the patents review process. Moreover, inclusion complexes have been an alternative in developing treatment mainly in China by the pharmaceutical industries in several countries such as Germany, Hungary, the United States of America, Japan and China.

EXPERT OPINION

This review is broad and complete since it considers the first patent involving cyclodextrins and antibacterial drugs. Therefore, the various inclusion complexes and antibacterial drugs alternatives presented in this review offer therapeutic options to fight bacterial infections. If shown to be effective, these drugs may be extremely important in the current clinical practice.

A novel terpolymer nanocomposite (carboxymethyl β-cyclodextrin-nano chitosan-glutaraldehyde) for the potential removal of a textile dye acid red 37 from water

Carboxymethyl β-cyclodextrin-nanochitosan-glutaraldehyde (CM-βCD:nChi:Glu) terpolymer was prepared as a nano-adsorbent for the removal of the anionic textile dye, acid red 37. The terpolymer nanocomposite formation and characterization were clarified by FTIR, XRD, scanning electron microscopy, TEM, Brunauer-Emmett-Teller specific surface area (BET-SSA), and zeta potential. The removal of the textile dye was investigated by using the batch adsorption method, investigating the effect of pH, dye concentration, adsorbent dose, contact time, and temperature. The results revealed that the maximum removal efficiency of 102.2 mg/L of the dye is about 99.67% under pH 6.0, the optimal contact time is 5 min, and the adsorbent dosage is 0.5 g/L. At 29°C; the adsorption capacity increased from 81.29 to 332.60 mg/g when the initial concentration of the dye was increased from 40.97 to 212.20 mg/L. Adsorption kinetics fitted well with the pseudo-second-order model with a good correlation (R ² = 0.9998). The Langmuir isotherm model can best describe the adsorption isotherm model. Based on the experimental results, the CM-βCD:nChi:Glu terpolymer has a promising potential as an efficient novel adsorbent for the removal of textile dye acid red 37 from contaminated water. This study's preparation techniques and demonstrated mechanisms offer valuable insights into the adsorbent-adsorbate interactions mechanism, analysis, challenges, and future directions of beta-cyclodextrin/chitosan-based adsorbents in wastewater treatment.

Exploration of long afterglow luminescent materials composited with graphitized carbon nitride for photocatalytic degradation of basic fuchsin

The frequent exposure of the widely used dye, basic fuchsin (BF), is seriously threatening the health of human central nervous system. Thus, removing the environmental pollution caused by BF is crucial, and photocatalytic technology recently has been used to degrade the pollutions dye. In this study, the binary composite SrAl₂O₄:Eu²⁺, Dy³⁺/g-C₃N₄ was prepared by high-temperature calcination and then applied in BF photodegradation. The results confirmed that the composite material had lower band gap value (Eg) and stronger visible light absorption ability. The photocatalytic capacity of the new composite materials was enhanced compared to that of the non-composite materials. By using the new binary-composited materials, 80% of BF could be degraded in 10 min, and the degradation ratio reached 100% in 30 min. More importantly, even the light source was removed, the photocatalytic reaction could continue due to the luminescence of SrAl₂O₄:Eu²⁺, Dy³⁺, and the degradation efficiency of BF could finally reach more than 90% within 3 h. By quenching experiments and electron spin resonance (ESR) spectra analysis, superoxide anion (·O₂^-) was verified to be the main active substance in this reaction process. Moreover, the excellent stability and recyclability of this catalyst was also proved. Furthermore, the new composite materials were utilized to degrade the BF aqueous solution and actual lake water, and the total organic matter contents (TOC) were measured. TOC values in these two systems decreased after photocatalytic reaction, which indicated that this catalyst has a great development prospect in the removal of organic matter in water. Our study confirmed a new kind of material of high performance with great significance for emergency treatment of water pollution in practical applications.

When MXene (Ti3C2Tx) meet Ti/PbO2: An improved electrocatalytic activity and stability

Stable electrode materials with high catalytic activity are urgently required for electrochemical degradation of refractory organic pollutants in wastewater treatment. Herein, high conductive MXene (Ti₃C₂T_x) was firstly fabricated by electrophoretic deposition (EPD) as an interlayer for preparing a novel PbO₂ electrode. The well-conducted Ti₃C₂T_x interlayer significantly improved the electrochemical performance of the EPD-2.0/PbO₂ (EPD time was 2.0 min) electrode with the charge transfer resistance decreased by 9.51 times, the inner active sites increased by 5.21 times and the ∙OH radicals generation ability enhanced by 4.07 times than the control EPD-0/PbO₂ anode. Consequently, the EPD-2.0/PbO₂ electrode achieved nearly 100% basic fuchsin (BF) and 86.78% COD removal efficiency after 3.0 h electrolysis. Therefore, this new PbO₂ electrode presented a promising potential for electrochemical degradation of BF and the new Ti₃C₂T_x middle layer could also be used to fabricate other efficient and stable anodes, such as SnO₂, MnO₂, TiO₂, etc.

Structural Adaptive, Self-Separating Material for Removing Ibuprofen from Waters and Sewage

β-Cyclodextrin nanosponge (β-CD-M) was used for the adsorption of ibuprofen (IBU) from water and sewage. The obtained material was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), Barrett-Joyner-Halenda (BJH), Harkins and Jura t-Plot, zeta potential, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and elementary analysis (EA). Batch adsorption experiments were employed to investigate the effects of the adsorbent dose, initial IBU concentration, contact time, electrolyte ions and humic acids, and sewage over adsorption efficiency. The experimental isotherms were show off using Langmuir, Freundlich, Hill, Halsey and Sips isotherm models and thermodynamic analysis. The fits of the results were estimated according to the Sips isotherm, with a maximum adsorption capacity of 86.21 mg g-1. The experimental kinetics were studied by pseudo-first-order, pseudo-second-order, Elovich, modified Freundlich, Weber Morris, Bangham's pore diffusion, and liquid film diffusion models. The performed experiments revealed that the adsorption process fits perfectly to the pseudo-second-order model. The Elovich and Freundlich models indicate chemisorption, and the kinetic adsorption model itself is complex. The data obtained throughout the study prove that this nanosponge (NS) is extremely stable, self-separating, and adjusting to the guest structure. It also represents a potential biodegradable adsorbent for the removal IBU from wastewaters.