Biodegradable tamarind kernel powder/kappa-carrageenan hydrogel for efficient removal of cationic dyes from effluents.

As an adsorbent for wastewater treatment, an eco-friendly biodegradable hydrogel was utilized in an effort to reduce the hydrogel production costs and decrease its negative impact on the environment. The biodegradable hydrogel of natural polysaccharides, tamarind kernel powder (tkp) with kappa-carrageenan (kcg), was employed as an adsorbent to remove cationic dyes from an aqueous environment. The impact of factors such as initial adsorbate concentration, pH, contact time, temperature, and adsorbent dosage on maximum adsorption were investigated. The tkp-kcg hydrogel has a remarkable swelling percentage of 1840%. The high water penetration of the tkp-kcg hydrogel made the internal adsorption sites for safranin (SF) and auramine-O (AO) dye adsorption accessible. The correlation coefficient supported the Langmuir isotherm model's applicability, with maximum adsorption efficiency of 9.372 mg g-1 for SF and 9.225 mg g-1 for AO. The kinetics of adsorption revealed a pseudo-second order process. Adsorption was an exothermic and spontaneous, according to thermodynamic analyses. Furthermore, the adsorbent was effectively used for five consecutive cycles of SF and AO dye adsorption-desorption. The biodegradation of tkp-kcg hydrogel was characterized by percentage of weight loss, Fourier transform infrared and scanning electron microscopy techniques. The composting technique of biodegradation was used in the biodegradation studies. Using the composting process, 92.6% of the synthesized hydrogel was degraded after 70 days. The results demonstrated that the hydrogel has a high microbiological biodegradability. It is believed that the tkp-kcg hydrogel could have excellent wastewater and agricultural applications due to its high water absorption, excellent retention capacities, cost-effective and ecofriendly synthesis. PRACTITIONER POINTS: Microwave assisted tkp-kcg hydrogel was synthesized with the swelling percentage of 1840%. Synthesized hydrogel showed excellent cationic dyes (SF and AO) adsorption capacity with a good recyclability. The synthesized hydrogel showed very good biodegradability of 92.6 % in 70 days by using composite method.

Sustained release of edaravone from (2-hydroxypropyl)-ß-cyclodextrin mediated tamarind kernel powder/kappa-carrageenan hydrogel: Microwave-assisted synthesis and optimization using experimental design.

In the current study, a sustained release formulation made of natural polysaccharide tamarind kernel powder/kappa-carrageenan and (2-hydroxypropyl)-ß-cyclodextrin (2-Hp-ß-CD) was chosen to increase drug effectiveness. A kappa-carrageenan and tamarind kernel powder 3-D hydrogel network was synthesized with the aid of microwave irradiations. The ICs complexes were prepared using a physical mixture (PM), kneading (KM), and microwave (MW) approach and were then successfully loaded into the hydrogel. The synthesis of ICs was verified as a true IC using DSC, SEM, FTIR, 1H NMR, and 2D NMR ROESY. A study on the in vitro sustained release of EV at pH 2, 7, and 7.4 was conducted at 37 °C. The microwave (MW) method was the most effective method for preparing true ICs of EV and 2-Hp-ß-CD for sustained drug release, as evidenced by the drug release data, which indicated that PM and KM displayed a burst release of the drug. Ritger-Peppas and Peppas-Sahlin were essential models for drug release. A phase solubility analysis was done to evaluate the IC's stoichiometry and complexation constant. Studies on drug release have shown that 2-Hp-ß-CD was effective at causing pH-responsive sustained drug release.

Cyclodextrin mediated controlled release of edaravone from pH-responsive sodium alginate and chitosan based nanocomposites.

The objective of the study is to enhance the aqueous solubility and stability of edaravone, a free radical scavenger drug. Inclusion complexes of edaravone with ß-cyclodextrin were prepared by microwave irradiation and physical mixture method and confirmation of inclusion complexes were investigated by different analytical techniques such as FT-IR, ROESY, DSC, and 1H NMR. pH-sensitive nanocomposites based on chitosan (CH), sodium alginate (ALG), and bentonite (BN) were synthesized. To get the maximum percentage swelling different reaction parameters that are responsible for the synthesis of the nanocomposite were optimized and characterized by various techniques such as FESEM, EDS, XRD, and FT-IR. To regulate the drug delivery, inclusion complexes were directly loaded into the CH/ALG hydrogel, and CH/ALG/BN nanocomposite and release studies were evaluated at different pH environments. The solubility of edaravone was investigated by phase solubility and the graph results in a typical AL type behavior, suggesting the formation of a 1:1 stoichiometry inclusion complex. The comparative evaluation of drug release was explored by kinetic models. Controlled release of drug was achieved from CH/ALG/BN nanocomposite in comparison to CH/ALG hydrogel. The exploratory kinetic investigation revealed that ß-CD plays a critical role in the drug release process by influencing polymer relaxation, resulting in slow release.

Comparative Evaluation for Controlled Release of Amoxicillin from RSM-CCD-Optimized Nanocomposites Based on Sodium Alginate and Chitosan-Containing Inclusion Complexes.

Amoxicillin (AMX) is a semisynthetic antibiotic, an analogue of ampicillin, with a wide spectrum of bacterial activity against many microorganisms but possesses some limits. To increase the drug effectiveness, supramolecule nanocomposites composed of ß-cyclodextrin (ß-CD) and chitosan/sodium alginate/GO were chosen in the present study as a sustained release formulation. Nanocomposites of chitosan (CH), sodium alginate (ALG), and graphene oxide (GO) were synthesized at 50 °C. The inclusion complexes (ICs) were processed via the physical mixture (PM), kneading (KM), microwave (MW) method, or coprecipitation (CP) and directly loaded into the nanocomposite. To confirm the formation of true ICs, the ICs were analyzed by DSC, SEM, 1H NMR, 2D NMR ROESY, and XRD. A drug release study was performed to find out which method is best for the controlled release of drugs in different environments of pH 2, 7, and 7.4 at 37 °C. From the observed drug release data, it was found that PM and KM showed a burst release of drugs and the microwave method was the most suitable method to prepare exact ICs of AMX and ß-CD for sustained release of drugs. Kinetics of drug release was analyzed by various kinetic models, and it was observed that the Korsmeyer-Peppas and Peppas-Sahlin models were best fit for drug release in all cases. A Phase solubility study was carried out to find the stoichiometry of IC formation and the complexation constant. The drug release was controlled and pH-dependent, confirming that nanocomposites are pH-sensitive. From drug release analysis, it was acknowledged that ß-CD is capable of causing sustained drug release.

Controlled release of vitamin B1 and evaluation of biodegradation studies of chitosan and gelatin based hydrogels.

Thiamine, also known as vitamin B1, is a vitamin synthesized for dietary supplementation and medication. In order to improve dissolution, bioavailability and sustained release of Thiamine, we prepared Thiamine hydrochloride (TH) and beta-cyclodextrin (ß-CD) host-guest solid inclusion complexes by microwave irradiation and studied the chemical characteristics and drug delivery potential of the complex. Based upon the molecular docking and phase solubility studies, we proposed the most probable structure of 1:1 inclusion complex. The value of the apparent stability constant was found to be 122.437 ± 4 M-1. Furthermore, Chitosan-Gelatin hybrid polymer networks (HPNs) containing ß-CD: TH inclusion complexes (ICs) were synthesized and the drug release was studied. It was found that TH releases in a more controlled manner from the ICs compare to the directly loaded TH into the HPN. The continuous progress of biodegradation at different stages was tested through FTIR and SEM characterization, which showed HPNs synthesized are biodegradable and composting method was found to be more efficient than soil burial method. Overall, our study describes that microwave-induced synthesis of ICs is efficient, time-saving, and environment-friendly, and the ICs are useful for a controlled release of Vitamin B1; thus, highlighting their potential in therapeutics of Vitamin B1 deficiency.

Self-assembled GO incorporated CMC and Chitosan-based nanocomposites in the removal of cationic dyes.

The purpose of the present study is to synthesise a self assembled nanocomposite by incorporating GO nanosheets into the polymer network of carboxy methyl cellulose and chitosan without using any initiator and cross-linker system. By incorporation of GO nanosheets, a great enhancement in various properties likes surface roughness, percentage swelling (from 2347% to 4633.8%) and adsorbent properties. The nanocomposite samples were investigated for removal of various kinds of dyes from waste water sources and were found highly selective for different cationic dyes. The adsorbent showed 97.9% removal of BG in 7 h whereas 100% removal of MB in just 1.5 h. The adsorption kinetics statistics fitted well in pseudo-second order rate equation. The correlation values and favourable RL of adsorption data suggested better fit for Langmuir adsorption for both the dyes.

Comparative study on the behaviour of Chitosan-Gelatin based Hydrogel and nanocomposite ion exchanger synthesized under microwave conditions towards photocatalytic removal of cationic dyes.

The present work reports the comparison study of Chitosan-Gelatin based hydrogels with their nanocomposite ion exchangers synthesized under microwave conditions for the adsorption and photodegradation of the cationic dyes. In this report, the hydrogel based on Chitosan-Gelatin, more selective for anionic dyes is modified to nanocomposite ion exchanger by incorporating the zirconium (IV) selenophosphate to make it selective for cationic dyes. The nanocomposite was investigated with a tremendous hike in the degradation capacity (99% from 12%) of MB after being modified to nanocomposite ion exchanger. Adsorption process followed Langmuir adsorption (Qo = 10.46 mgg-1) and non linear PFO kinetic model with k1, qe (calculated), R2, RMSE = 0.011, 1.02 (mgg-1), 0.996, and 0.01709 respectively.

Studies on the properties and biodegradability of PVA/Trapa natans starch (N-st) composite films and PVA/N-st-g-poly (EMA) composite films.

The morphological modification of Trapa natans starch was done by grafting the methylmethacrylate (EMA) using ferrous ammonium sulphate­potassium persulphate as a redox initiator. Different reaction parameters such as reaction temperature, time, monomer concentration, pH and solvent were optimized to get maximum graft yield (56%). The graft copolymers thus formed were characterized by Fourier transform infrared, scanning electron microscopy, X-ray diffraction and TGA/DTA/DTG techniques. PVA/starch (N-st) composite films and PVA/N-Starch-grafted-poly (EMA) composite films were prepared separately by using glycerol as a plasticizer. The effect and content of grafted starch on the mechanical properties, water uptake (%), and biodegradability of the composite films were observed. Elongation at break % of PVA/starch-grafted-poly (EMA) (1:1) increased up to 38.9% of pure PVA/N-starch composites (1:1). With further increase in the ratio of grafted starch from (50% to 70%) Elongation at break, % increased to a great extent. There was 223.14% increased in PVA/starch-grafted-poly (EMA) (3:7) as compared to pure PVA/N-starch (3:7) composite films. The Max stress increased up to 100% in PVA/N-starch-grafted-poly (EMA) (3:7) composite film of pure PVA/N-starch composite films (3:7). There were 41.63% decreases in water uptake in PVA/N-starch-grafted-poly (EMA) (3:7) composite films as compared to PVA/N-starch composite films.

Microscopic Investigations into the Effect of Surface Treatment of Cathode and Electron Transport Layer on the Performance of Inverted Organic Solar Cells.

Surface treatments of various layers in organic solar cells play a vital role in determining device characteristics. In this manuscript, we report on the influence of surface treatment of indium tin oxide (ITO) electrode and electron transport layer (ETL), ZnO, on the photovoltaic performance of inverted organic solar cells (IOSC) and their correlation with the surface chemistry and surface potential as studied using X-ray photoelectron spectroscopy (XPS) and Kelvin probe force microscopy (KPFM), using the device structure glass/ITO/ZnO/P3HT: PCBM/MoO3/(Au or Ag) (P3HT, poly(3-hexylthiophene-2,5-diyl), and PCBM, phenyl-C61-butyric acid methyl ester). Our results show that although ozonization of ITO leads to an improvement in the device power conversion efficiency, the ozonization of a subsequent ZnO layer results in a decreased performance mainly because of a decrease in the fill factor (FF). However, subsequent methanol (CH3OH) treatment of ZnO layer on an ozonized ITO electrode shows substantial improvement with device efficiencies exceeding ∼4% along with superior reproducibility of the devices. Furthermore, a detailed analysis of the surface wettability, chemistry, and surface potential using contact angle measurements, XPS, and KPFM attribute the improvements to the elimination of surface defects and the changes in the surface potential. Finally, impedance analysis suggests that methanol treatment of the ZnO layers leads to the development of a favorable nanophase structure with higher conductivity, which is otherwise indiscernible using microscopic methods.

Synthesis and flocculation properties of gum ghatti and poly(acrylamide-co-acrylonitrile) based biodegradable hydrogels.

This article reports the development of biodegradable flocculants based on graft co-polymers of gum ghatti (Gg) and a mixture of acrylamide and acrylonitrile co-monomers (AAm-co-AN). The hydrogel polymer exhibited an excellent swelling capacity of 921% in neutral medium at 60°C. The polymer was used to remove saline water from various petroleum fraction-saline water emulsions. The flocculation characteristics of the hydrogel polymer were studied in turbid kaolin solution as a function of the amount of polymer and the solution temperature and pH. Biodegradation studies of hydrogel polymer were conducted using the soil composting method, and the degradation process was constantly monitored using scanning electron microscopy and Fourier transform infrared spectroscopy techniques. The results demonstrated an 89.47% degradation of the polymer after 60 days. Finally, the hydrogel polymer adsorbed 98% of cationic dyes from the aqueous solutions.

Porous solgel fiber as a transducer for highly sensitive chemical sensing.

A novel solgel process for making porous silica fiber and doping the fiber core with sensing material is described. A CoCl(2) -doped solgel fiber was fabricated and was used to construct an active-core optical fiber moisture sensor. Test results show that the sensitivity of the active-core optical fiber sensor is much higher than that of an evanescent-wave-based optical fiber sensor.