Preparation and Characterization of Magnetic Chitosan/-Carrageenan Nanocomposite and its Application for Removal of Eriochrome black-T from Aqueous Solutions

Due to the non-biodegradability of some dyes especially water soluble dyes, dye can pollute surface and groundwaters. Subsequently, discharging dye-contaminated wastewaters in the environment can endanger the human and aquatic life. In this work, a chitosan-based magnetic adsorbent was used for removal of anionic eriochrome black T. Magnetic nanoparticles were synthesized in situ in the presence of chitosan. The obtained magnetic chitosan was then crosslinked with kappa-carrageenan in order to overcome the solubility of chitosan under acidic conditions. The structure of magnetic adsorbent was investigated by XRD, SEM, TEM, FT-IR, and VSM techniques. The removal of eriochrome black T by magnetic adsorbent was studied regarding dye concentration, pH, temperature, ionic strength, and contact time. The experimental adsorption isotherms were in good accordance with the Langmuir model. According to the Langmuir constants, the maximum adsorption capacity of magnetic adsorbent was acquired 150 mg/g. The adsorption kinetic data were properly described according to the pseudo-second-order kinetic model. A decrease in dye adsorption capacity of the adsorbent was observed as the pH of dye solution was increased. The ease of preparation for magnetic adsorbent and its high adsorption capacity for eriochrome black T makes it a good candidate for removal of pollutants

Preparation of a Novel Magnetic Nanocomposite Hydrogel Based on Carboxymethyl Chitosan for the Adsorption of Crystal Violet as Cationic Dye

The novel magnetic carboxymethyl chitosan/poly (acrylic amide) hydrogel (m-CMC-PAMH) was prepared using magnetic montmorillonite (m-MMT) and characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and vibrating sample magnetometry (VSM) techniques. Results showed that m-CMC-PAMH has been prepared successfully properties without damaging the crystal structure of Fe3O4. Adsorption capacity of Crystal Violet (CV) on the m-CMC-PAMH was 72.4 mg/g. The CV adsorption well described by the pseudo-second-order kinetics and Langmuir isotherm equations. The positive value of the enthalpy change ΔH° (23.5 kJ/mol) showed that the adsorption was endothermic and physical in nature. The value of Gibbs free energy change ΔG° was found to be -9.7 kJ/mol at 295 K for m-CMC-PAMH, which shows spontaneity of the CV adsorption. So, m-CMC-PAMH can be used as a low-cost alternative to other adsorbents for the removal of dyes from aqueous solutions

Carrageenan-based semi-IPN nanocomposite hydrogels: Swelling kinetic and slow release of sequestrene Fe 138 fertilizer

Nanocomposite hydrogels based on kappa-carrageenan were synthesized by incorporating natural sodium montmorillonite (Cloisite) nanoclay. Acrylamide (AAm) and methylenebisacrylamide (MBA) were used as a monomer and a crosslinker, respectively. Effects of reaction variables on the swelling kinetics were studied. The results revealed that the rate of swelling for nanocomposites with high content of MBA was higher than those of nanocomposites consisting of low content of MBA. Similar to the effect of MBA, the rate of swelling enhanced as the carrageenan content was decreased. The influence of clay content on swelling rate was not remarkable. The experimental swelling data were evaluated by pseudo-first-order and pseudo-second-order kinetic models. The swelling data described well by pseudo-second-order kinetic model. Sequestrene Fe 138 (Sq) as an agrochemical was loaded into nanocomposites and releasing of this active agent from nanocomposites was studied. The clay-free hydrogel released the whole loaded Sq; whereas the presence of clay restricted the release of Sq

Dual-drug (Curcumin/Ciprofloxacin) loading and release from chitosan-based hydrogels embedded with magnetic Montmorillonite/Hyaluronic acid for enhancing wound healing

Abstract Montmorillonite (MMt) is extensively applied as an efficient drug-carrier in designing drug delivery systems (DDS) due to its high specific surface area to load drugs. Modification of MMt via iron (Fe) blending can thus be a desirable method to improve its biocompatibility. Herein, magnetic nano-carriers involving the magnetic MMt (mMMt) core surrounded by chitosan (Chito) as a biopolymer and hyaluronic acid (HA) were prepared. To coat the mMMt fabricated through the coprecipitation of the Fe3+/Fe2+ ions in the presence of MMt, the acquired mMMt as the core was then treated with the Chito/HA solution to induce the cross-linked Chito/HA as the shell (namely, the Chito/HA-mMMt). The transmission electron microscopy (TEM) results accordingly revealed the existence of the mMMt inside the Chito/HA solution. Curcumin (CUR) and ciprofloxacin (CIP) were further employed as two model drugs. The CUR and CIP release from the Chito/HA-mMMt subsequently occurred in a sustained manner and pH-dependently. Additionally, an upsurge in the CUR and CIP release by applying an external magnetic field was observed. Thus, the prepared Chito/HA-mMMt hydrogels promise an outstanding potential performance in terms of expanding novel pH-dependent DDS with a sustained release behavior. The scratch assay of the given hydrogels also confirms their applications for wound healing

Magnetic/pH-sensitive nanocomposite hydrogel based carboxymethyl cellulose –g- polyacrylamide/montmorillonite for colon targeted drug delivery

Objective(s): The main aim of current research was to develop a novel magnetically responsive hydrogel by radical polymerization of carboxymethyl cellulose (CMC) on acryl amide (Am) using N,N'-methylene bis acrylamide  (MBA)  as a crosslinking agent, potassium persulfate (KPS) as a free radical initiator, and  magnetic montmorillonite ( mMT)  nanoclay as nano-filler. Methods: The new product (CMC-g-Am/mMT) was characterized by FT-IR, XRD, TEM, SEM, and VSM techniques. Drug loading and release efficiency were evaluated by Diclofenac Sodium (DS) as a model drug. Results:SEM results demonstrated that magnetic nanoclay (mMT) can cause a rough morphology. Transmission electron microscopy (TEM) indicated the formation of MNPs into the montmorillonite clay structure with the final average particle size of around 100 nm. Furthermore, according to the in vitro drug release profiles, the maximum cumulative release was around 79% at pH=7.4 under applied magnetic field. Conclusions: The results indicate that the prepared CMC-g-Am/mMT platform can be used for delivery of drugs to the colon by applying an external magnetic field

Effect Of Chitosan Application On The Performance Of Lentil Genotypes Under Rainfed Conditions

In the current study, influences of chitosan solutions on morphological characteristics, growth and yield components of lentil (Lens culinaris Med.) under rainfed conditions have been investigated. A field experiment was conducted in the Northwest of Iran using a split-plot experiment based on a completely randomized design with three replications. The response of twelve genotypes with different origins to chitosan application at the sowing (seed soaking), vegetative and reproductive stage (spraying chitosan onto leaves) was evaluated. Results revealed that chitosan application could significantly improve the number of pods per plant, 100-seed weight, grain yield per plant and harvest index in comparison to control plants. The comparison of yield components between chitosan treatments showed that spraying chitosan during the reproductive stage was more efficient than in other stages. However, the responses of the number of pods per plants and grain yield per plants to chitosan treatments were significantly different among the genotypes. Although the highest grain yield was recorded in the 78S 26013 genotype (from Jordan), its response to chitosan treatments was different from the other genotypes and showed the best performance in plants obtained from seed soaked in chitosan solutions. We suggest that the application of chitosan as an agronomic management strategy be further investigated for an efficient technique to induce resistance in lentil plants against biotic and drought stress in semi-arid regions

Effect of Chitosan nanoparticles on quality indices, metabolites, and vase life of Rosa hybrida cv. Black magic

Abstract Background Chitosan nanoparticles (CTS-NPs) protect the active ingredients from the environment for a specific period and reduces sweating, control weight loss, delay ripening, and increase vase life. So, a factorial experiment was carried out as a randomized complete design in three replications to investigate the efficiency of CTS-NPs in quality improvement and longevity extension of cut rose flowers. Results The 15-day maximum vase life was attained by the rose placed in a preservative solution containing 10 mg L−1 CTS-NPs. CTS-NPs also reduced microbial growth as compared to controls. Total phenolics, total flavonoids, and amount of anthocyanin in treated petals were dramatically increased. CTS-NPs solutions especially at 10 and 15 mg L−1 concentrations, markedly reduced the H2O2 and malondialdehyde at the end of 15th day and maintained the membrane index. The protein and carbohydrate and petals anthocyanin content and enzymatic activities such as superoxide dismutase, polyphenol oxidase, peroxidase, catalase and ascorbate peroxidase increased in cut roses placed in 10 mg L−1 CTS-NPs vase solution which in turn caused to increase in vase life. Conclusion CTS-NPs especially at a level of 10 mg L−1 can assist plants to enhance light usage efficiency, as well as promote photosynthetic carbon fixation and the production of additional carbohydrate products for plant growth and development. Graphical Abstrac

Adsorption of Cationic Dyes on a Magnetic 3D Spongin Scaffold with Nano-Sized Fe3O4 Cores

The renewable, proteinaceous, marine biopolymer spongin is yet the focus of modern research. The preparation of a magnetic three-dimensional (3D) spongin scaffold with nano-sized Fe3O4 cores is reported here for the first time. The formation of this magnetic spongin–Fe3O4 composite was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential thermal analysis (DTA) (TGA-DTA), vibrating sample magnetometer (VSM), Fourier-transform infrared spectroscopy (FTIR), and zeta potential analyses. Field emission scanning electron microscopy (FE-SEM) confirmed the formation of well-dispersed spherical nanoparticles tightly bound to the spongin scaffold. The magnetic spongin–Fe3O4 composite showed significant removal efficiency for two cationic dyes (i.e., crystal violet (CV) and methylene blue (MB)). Adsorption experiments revealed that the prepared material is a fast, high-capacity (77 mg/g), yet selective adsorbent for MB. This behavior was attributed to the creation of strong electrostatic interactions between the spongin–Fe3O4 and MB or CV, which was reflected by adsorption mechanism evaluations. The adsorption of MB and CV was found to be a function of pH, with maximum removal performance being observed over a wide pH range (pH = 5.5–11). In this work, we combined Fe3O4 nanoparticles and spongin scaffold properties into one unique composite, named magnetic spongin scaffold, in our attempt to create a sustainable absorbent for organic wastewater treatment. The appropriative mechanism of adsorption of the cationic dyes on a magnetic 3D spongin scaffold is proposed. Removal of organic dyes and other contaminants is essential to ensure healthy water and prevent various diseases. On the other hand, in many cases, dyes are used as models to demonstrate the adsorption properties of nanostructures. Due to the good absorption properties of magnetic spongin, it can be proposed as a green and uncomplicated adsorbent for the removal of different organic contaminants and, furthermore, as a carrier in drug delivery applications