Nanocomposite Gel Research Articles

Feasibility Study of Using graphene Oxide/silica Gel Nanocomposite Prepared by Sol-gel Method for Removing Malachite Green from Aqueous Solutions: Optimization, Kinetic, and Isotherm Studies

The main objective of this work was to evaluate the feasibility of the application of GO/Na2SiO3 nanocomposite as highly efficient adsorbent for the removal of malachite green as a cationic dye from aqueous solutions. To do so, first the synthesized nanosorbent was characterized via FTIR, SEM, TEM and XRD techniques. Surface area and pore mean size of above mentioned nanocomposite were determined using BET technique. Also, some important parameters affecting the efficiency of the absorption of malachite green, such as pH, adsorbent dosage, contact time, primary concentration of dye and salt effect were optimized. The malachite green (water-soluble) dye was analyzed at a maximum wavelength of 618 nm. The optimal conditions for removal of malachite green from aqueous solution included a 20 mg l-1 initial concentration with 25 mg adsorbent at pH 7, and adsorption equilibrium was achieved within 5 min. Kinetic studies confirmed that dye adsorption process followed pseudo-second order kinetic models (R2 = 0.9999) and adsorption equilibrium data showed good correlation with Freundlich isotherm (R2=0.9982 at 298 K). Thermodynamic analysis indicates that the adsorption process is spontaneous and exothermic in nature. In addition, the experimental data obtained from reusability studies showed that the prepared adsorbent could be used in up to six adsorption-desorption cycles without significant decrease in removal efficiency.

Experimental Investigation of Low-Concentrated Nanocomposite Polymer Gels for Water Shutoff Treatment Under Reservoir Conditions

Summary Excessive water production is one of the main challenges in mature oil fields. Applying polymer gels has proven to be an effective chemical treatment to this problem. Because of some limitations in application of polymer gels in oil reservoirs with harsh conditions, using nanoparticles (NPs) in gel structure has been proposed recently to improve the performance of such systems. However, while main body of the previous studies has only focused on improvement of bulk properties of polymer gels in presence of NPs, there is a serious lack of data on their performance in porous media. In this study, we have conducted a comprehensive investigation on application of two new nanocomposite polymer gels through bulk-gel static tests and dynamic core displacement tests. Fe2O3 and NiO NPs at low concentrations (<100 mg·L−1) in AN125VLM/chromium acetate polymer gel system were used. The results of bulk bottle tests at 82℃ demonstrated that the nanocomposite gel systems have the same gelation time and gel strength as the NPs-free gel. Swelling ratio measurements were also performed in a high-salinity formation water (268 949 mg·L−1), and accordingly, while NiO NPs deteriorated the swelling behavior of the gel system, Fe2O3 NPs showed a positive impact. The results of the strain-sweep test demonstrated relatively similar linear viscoelastic region and thus the same gel strength for all gel samples. In addition, the results of the thermogravimetric analysis (TGA) revealed that Fe2O3 NPs had a minor positive impact on thermal resistance of the polymer gel system. Finally, high pressure-high temperature coreflooding experiments were carried out on three sandstone reservoir core samples. Although the NPs-free gel showed a desirable level of disproportionate permeability reduction, the injection of Fe2O3 nanocomposite gel showed unsatisfactory results and caused rock permeability degradation. The pressure drop trend and deposition of polymer gel particles at the upstream injection side confirmed the aggregation and plugging effect of NPs during injection. Our findings demonstrate the critical aspect of dynamic core displacement testing of nanocomposite gels before their use for field applications.

Poly(poly[ethylene glycol] methyl ether methacrylate)/graphene oxide nanocomposite gel polymer electrolytes prepared by controlled and conventional radical polymerizations for lithium ion batteries

Nanocomposite gel polymer electrolyte (GPE) films based on poly(poly[ethylene glycol] methyl ether methacrylate)/graphene oxide (GO) (P[PEGMA-GO]) have been prepared by in situ conventional free radical polymerization (FRP) and reversible addition-fragmentation chain transfer (RAFT) polymerization as controlled radical polymerization (CRP) using 2-cyano-2-propyl dodecyl trithiocarbonate (CPDT) as RAFT agent. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) showed that prepared nanocomposite films had amorphous structure and also, thermogravimetric analysis (TGA) showed appropriate thermal stability of samples. GPEs prepared via FRP showed slight higher ionic conductivity that GPEs prepared via RAFT polymerization. In both synthetic approaches, an optimum GO amount of 0.3 wt. % was obtained considering ionic conductivity. At ambient temperature, P(PEGMA-GO) with 0.3 wt. % GO prepared via FRP indicated the highest ionic conductivity of 4.05 × 10−3 S cm−1, a satisfactory lithium ion transference number (t+) of 0.6, and the excellent interface compatibility with electrodes. The lithium ion battery with P(PEGMA-GO0.3%) as GPE also exhibited electrochemical stability window up to 4.6 V vs. Li/Li+, a high charge-discharge capacity of 179 mAh g−1 at 0.1 C, and capacity retention of 91% after 100 cycles.

Experimental Investigation of a Novel Nanocomposite Particle Gel for Water Shutoff Treatment in Mature Oilfields.

Conventional preformed particle gels suffer from insufficient salt tolerance and weak mechanical properties after water absorption, which reduce the water shutoff effect in mature oilfields. In this paper, a nanocomposite particle gel (NCPG) is synthesized by copolymerization of acrylamide (AM) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) using laponite RD (LPT) as a physical cross-linker and N,N-methylene-bisacrylamide (MBA) as a chemical cross-linker via in situ free radical polymerization. Compared with the NCPG without LPT, both the swelling rate and mechanical properties of NCPG added with LPT are found to be improved. In addition, the pore sizes of the network of the swollen NCPG are smaller than those of the sample without LPT, and the thermal stability is also slightly enhanced. The swelling rate of NCPG increases with increasing AMPS concentration. The water absorbency of NCPG first increases and then decreases with increasing MBA and APS concentrations. The NCPG is sensitive to alkaline medium due to the presence of sulfonic acid groups on the molecular chains of the NCPG. The synthesized NCPG exhibits good salt tolerance at 80 °C in formation water. The plugging rate of the NCPG to a sand-pack is above 90%, and the residual resistance factor reaches 19.2 under reservoir conditions. These results indicate that the NCPG may have potential application for water shutoff treatment in mature oilfields.

Fabrication of Biobased Nanocomposites by Chemical Intervention of Nano‐Hydroxyapatite in Aloe Vera Gel‐Guava Seed Matrix for Bone Tissue Engineering

AbstractThe sharp increase in the bone defect related cases have derived an urgent search for novel bone implants which possess identical mechanical aspect as natural bone, along with commendable osteogenic property. Thus, to accomplish these requirements, in the present study, nano‐hydroxyapatite (nHA) reinforced guava seed (GS) – aloe vera (AV) gel nanocomposites were synthesized via a co precipitation approach with an attempt to induce bone mimicking activity. Three ternary systems were fabricated varying the concentration of different components as – nHA/GS/AV in the ratio of 70/20/10 (HGAV1), 70/15/15 (HGAV2) and 70/10/20 (HGAV3). All of the nanocomposites revealed a high cellular viability confirmed from fluorescence microscopy, increased osteogenic activity, phenomenal antibacterial activity, lower haemolysis, and high protein adsorption. These findings suggested that the use of natural products GS and AV gel for fabrication of nanocomposites gave them profound bioactivity and biocompatibility and exhibited a great potential in dental and orthopaedic applications.

Angiogenesis Promotion by Combined Administration of DFO and Vein Endothelial Cells Using Injectable, Biodegradable, Nanocomposite Hydrogel Scaffolds.

Desferrioxamine (DFO) upregulates HIF-1α and stimulates expression of vascular endothelial growth factor (VEGF), thereby accelerating neovascularization. As DFO acts primarily upon surrounding vein endothelial cells to stimulate angiogenesis, the angiogenic efficacy of DFO could be reduced in severely injured tissues lacking a sufficient number of vein endothelial cells. We hypothesized that combined administration of DFO and vein endothelial cells is a promising tissue engineering approach for promoting neovascularization. In this study, we evaluated the applicability of this approach using injectable, biocompatible, biodegradable nanocomposite gels consisting of poly(dl-lactide-co-glycolide)-b-polyethylene glycol-b-poly(dl-lactide-co-glycolide) (PLGA-PEG-PLGA) copolymers and clay nanoparticle LAPONITE. The nanocomposites exhibited irreversible thermo-gelation in the presence of DFO, and the mechanical strength was strongly affected by the amount of DFO. The storage moduli of the gels increased with increasing amount of DFO. These results indicate that the interaction between DFO and LAPONITE works as physical cross-linking points and facilitates the formation of the gel network. The nanocomposite gels achieved sustained slow release of DFO due to interactions between DFO and LAPONITE. Human umbilical vein endothelial cells (HUVECs) cultured on DFO-loaded nanocomposite gels exhibited a higher degree of vascular tube formation than cells cultured on nanocomposite gels without DFO. Moreover, the number of branching points and the diameter of the blood vessels regenerated in the gels significantly increased with increasing DFO amount, indicating that DFO released from the gels facilitates vascular tube-forming capacity. As a proof of concept, we demonstrate that the combined administration of DFO and vein endothelial cells using nanocomposite gels promotes greater angiogenesis than DFO administration alone using the same gels by in vivo experiments, confirming the validity of our hypothesis. Considering the multiple advantages of nanocomposite gels with regard to potential vascularization capacity, certain biocompatibility, biodegradability, and injectable cell- and drug-delivery capacity, we concluded that the nanocomposite gels have potential utility as scaffolding biomaterials for vascularization in tissue engineering applications.

Synthesis and Characterization of BaSO4-CaCO3-Alginate Nanocomposite Materials as Contrast Agents for Fine Vascular Imaging.

Microcomputed tomography is an important technique for distinguishing the vascular network from tissues with similar X-ray attenuation. Here, we describe a composite of barium sulfate (BaSO4) nanoparticles, calcium carbonate (CaCO3) nanoparticles, and alginate that provides improved performance over microscale BaSO4 particles, which are currently used clinically as X-ray contrast agents. BaSO4 and CaCO3 nanoparticles were synthesized using a polyol method with tetraethylene glycol as solvent and capping agent. The nanoparticles show good colloidal stability in aqueous solutions. A deliverable nanocomposite gel contrast agent was produced by encapsulation of the BaSO4 and CaCO3 nanoparticles in an alginate gel matrix. The gelation time was controlled by addition of d-(+)-gluconic acid δ-lactone, which controls the rate of dissolution of the CaCO3 nanoparticles that produce Ca2+ which cross-links the gel. Rapid cross-linking of the gel by Ba2+ was minimized by producing BaSO4 nanoparticles with an excess of surface sulfate. The resulting BaSO4-CaCO3 nanoparticle alginate gel mechanical properties were characterized, including the gel storage modulus, peak stress and elastic modulus, and radiodensity. The resulting nanocomposite has good viscosity control and good final gel stiffness. The nanocomposite has gelation times between 30 and 35 min, adequate for full body perfusion. This is the first nanoscale composite of a radiopaque metal salt to be developed in combination with an alginate hydrogel and designed for medical perfusion and vascular imaging applications.

3D bioprinting of hydrogel/ceramic composites with hierarchical porosity

Direct 3D bioprinting of bioreactors containing microorganisms embedded inside hydrogel structures is a promising strategy for biotechnological applications. Nevertheless, microporous hydrogel networks hinder the supply of nutrients and oxygen to the cell and limit cell migration and proliferation. To overcome this drawback, we developed a feedstock for 3D bioprinting structures with hierarchical porosity. The feedstock is based on a highly particle-filled alumina/alginate nanocomposite gel with immobilized E. coli bacteria with the protein ovalbumin acting as foaming agent. The foamed nanocomposite is shaped into a porous mesh structure by 3D printing. The pore radius diameters inside the non-printed, non-foamed nanocomposite structure are below 10 µm, between 10 and 500 µm in the albumin-stabilized foam and with additional pores in the range of 0.5 and 1 mm in the printed mesh structure. The influence of albumin on the bubbles and hence pore formation was analyzed by means of interfacial shear rheology and porosity measurements with X-ray microtomography (µCT). Furthermore, averaged diffusion coefficients of water in printed and non-printed samples with different albumin concentrations were recorded using nuclear magnetic resonance (NMR) tomography to assess the water content in the porous structure. Moreover, the effective viability and accessibility of embedded E. coli cells were analyzed for various material compositions. Here, the addition of albumin induced bacterial growth and the porosity increased the effective viability of the embedded bacteria, most likely because of enhanced accessibility of the cells. The experimental results demonstrate the potential of this approach for producing macroscopic bioactive materials with complex 3D geometries as a platform for novel applications in bioprocessing.

Green nanocomposite gels based on binary network of sodium alginate and percolating halloysite clay nanotubes for 3D printing

Alginate hydrogels with embedded rigid percolating network of halloysite clay nanotubes were evaluated as a novel ink for 3D printing. Hydrophilic alginate macromolecules adsorbing on halloysite stabilize the network of the nanotubes and form their own network of interlaced polymer chains. The effect of halloysite content on the structure and properties of the hydrogels was studied by rheometry, thermogravimetric analysis, FTIR-spectroscopy, dynamic light scattering, transmission electron microscopy, and 3D cryo-electron microscopy. Hydrogels demonstrate a very pronounced shear-thinning at extrusion and rather quick viscosity recovery after extrusion assigned to rapid rearrangement of the network structure promoted by mobile alginate chains. Even at low volume fractions (up to 0.054) the nanotubes reinforce the hydrogel increasing its storage modulus up to 650 Pa and inducing the appearance of yield stress. These properties make the alginate/halloysite hydrogels promising for the application in 3D printing for fabrication of green and sustainable nanocomposite materials made from natural components.

Effects of radical scavengers on nanocomposite Fricke gel for heavy ion beam irradiation

NC-FG (nanocomposite Fricke gel) dosimeter is a 3D dosimeter for heavy ion beam without LET dependence. In this study, we evaluate the effects of silver perchlorate, a radical scavenger, on NC-FG. We find that radiological properties of NC-FG are changed by small amounts of silver perchlorate. Especially, dose response at high LET enhanced.

Preparation and characterisation of graphene oxide containing block copolymer worm gels.

This paper reports a generic method for preparing reinforced nanocomposite worm-gels. Aqueous poly(glycerol monomethacrylate)-b-poly(2-hydroxypropyl methacrylate) (PGMA-PHPMA) and methanolic poly(glycerol monomethacrylate)-b-poly(benzyl methacrylate) (PGMA-PBzMA) worm gels were prepared by RAFT-mediated polymerisation-induced self-assembly (PISA). The former system undergoes a reversible worm-to-sphere degelation transition upon cooling to 5 °C whilst the latter system undergoes the same transition on heating to 56 °C. This transition allows these copolymer dispersions to be readily mixed with graphene oxide (GO) whilst in a low viscosity state and form nanocomposite gels on returning to room temperature via a sphere-to-worm transition. Various quantities of GO were added to the studied copolymer dispersions at a fixed copolymer content of 15% w/w. A general trend was observed whereby relatively small quantities of GO caused the gel strength of the nanocomposite gel to be higher than that of the pristine worm-gel, as determined by oscillatory rheology. Additional quantities of GO resulted in gel weakening or prevented gel-reformation altogether. For instance, 15% w/w PGMA52-PHPMA130 worm gels had a storage modulus (G') of approximately 1.5 kPa. The addition of 1.5% w/w GO based on the copolymer caused G' to increase to approximately 4.0 kPa but >1.5% w/w GO resulted in gel strengths <1.0 kPa. A combination of aqueous electrophoresis and transmission electron microscopy measurements were used to investigate the mechanism of nanocomposite gel formation. It was observed that the PGMA-based copolymers readily absorb onto the surface of GO. Thus, the role of GO is both to strengthen the worm-gels when an optimal concentration of GO is used, but also prevent worm-reformation if too much copolymer becomes absorbed on the surface of the sheets.

Poly(Acrylic Acid)-Based Nanocomposite Gel Polymer Electrolyte with High Mechanical Strength and Ionic Conductivity Towards Long-Cycle-Life Flexible Zinc–Air Battery

Poly(Acrylic Acid)-Based Nanocomposite Gel Polymer Electrolyte with High Mechanical Strength and Ionic Conductivity Towards Long-Cycle-Life Flexible Zinc–Air Battery

Role of Platelet-Rich Plasma Gel in Promoting Wound Healing Based on Medical Images of Wounds.

A wound is the pathological change of soft tissue under normal skin caused by various factors, such as collision, contusion, hot crush, avulsion, corrosive chemicals, operations, excessive wound tension after operations, local pressure that cannot be relieved for a long time, liquid immersion, local infection, and rejection reactions caused by allogeneic substances. The skin itself or its underlying soft tissue loses its integrity and continuity, thus losing its normal physiological function. Medical image analysis is a medical term that refers to the interdisciplinary fields of integrated medical imaging, artificial intelligence, digital image processing and analysis, mathematical modeling, and numerical algorithms. According to the time of wound formation, they can be divided into acute and chronic wounds. The common acute wounds include lacerations caused by trauma, surgical incisions, burns, and donor sites formed after skin graft operations. This article mainly studies the role of platelet-rich plasma gel nanocomposites in promoting wound healing. It is proven that ptt-rich plasma gel can significantly promote tissue repair and regeneration and accelerate wound healing in patients with severe burns. The atomic number of the nanocomposite has a better treatment effect on the nanoparticle approach. In this paper, chitosan nanocomposite membrane, nanocomposite algorithm, and the calculation method of enthalpy of formation of high alloy nanomaterials were used to study the role of ptt-rich plasma gel combined chitosan nanocomposite membrane loaded bone marrow stromal cells in promoting wound healing, and its effects were applied to the repair of special site burns, special burns, and different age burns. Good wound repair benefits from the correct treatment of the wound, which directly affects the stability and development of the internal environment. The difference in healing time between the two groups was statistically significant, and the recovery time of the PRP group was 0.001 less than that of the control group. The results showed that the wound healing time of the PRP group was significantly shorter than that of the control group (P < 0.05); after treatment, the content of VEGF in the wound tissue of the two groups increased, especially in the PRP group; the effective rate of the PRP group was 75.0%, which was higher than 68.8% of the control group. It can play an important role in the regulation of expression and the pathophysiological process of wound healing.

Silver Nanoparticulate Matter Reinforced Conducting Polymer Polyaniline Nanocomposite: Sol-Gel Processing, Schottky-Diode Making and Electronic Worthiness Testing

Abstract: Polyaniline nanoparticles is synthesized by chemical oxidation of aniline by copper sulphate. Chemical reduction of silver nitrate by sodium citrate yileds silver nanoparticles. Both aforesaid nanomaterials are mixded with polyvinyl alcohol to get nanocomposite gel. Nanoparticles are characterized by ultraviolet-visible absorption spectroscopy. Schottky diode is made by applying nanocomposite with copper wire on one side of aluminium foil and on other side attaching copper wire for another electrical contact. Current-voltage electrical characterization is analyzed by making simple circuit encompassing polyaniline/silver nanocomposite diode. Keywords: Nanoelecttronics, Nanoparticles, Polyaniline, Nanocomposite, Schottky-diode

Development, Optimization, and In Vitro Evaluation of Novel Oral Long-Acting Resveratrol Nanocomposite In-Situ Gelling Film in the Treatment of Colorectal Cancer.

This study aimed to develop and evaluate sustained-release (SR) long-acting oral nanocomposites in-situ gelling films of resveratrol (Rv) to treat colorectal cancer. In these formulations, Rv-Soy protein (Rv-Sp) wet granules were prepared by the kneading method and then encapsulated in the sodium alginate (NA) dry films. The prepared nanocomposite in-situ gels films were characterized using dynamic light scattering, Fourier-transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The optimized formulations were further evaluated based on drug encapsulation efficiency, pH-drug release profile, swelling study, and storage time effects. The optimized formulation was tested for its anticancer activity against colorectal cancer cells using the cytotoxicity assessment, apoptosis testing, cell cycle analysis, gene expression analysis, and protein estimation by the reverse-transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay methods, respectively. The optimum film showed encapsulation efficiency of 97.87% ± 0.51 and drug release of 14.45% ± 0.043 after 8 h. All physiochemical characterizations confirmed, reasoned, and supported the drug release experiment’s findings and the encapsulation assay. The Rv nanocomposite formulation showed concentration-dependent cytotoxicity enhanced apoptotic activity as compared to free Rv (p < 0.05). In addition, Rv nanocomposite formulation caused a significant increase in Bcl-2-associated protein X (Bax) and a decrease in expression of B-cell lymphoma 2, interleukin 1 beta, IL-6, and tumor necrosis factor-alpha (Bcl2, IL-1β, IL-6, and TNF-α respectively) compared to that of free Rv in HCT-116 cells. These results suggest that long-acting Rv nanocomposite gels could be a promising agent for colorectal cancer treatment.

Graphene oxide modulates inter-particle interactions in 3D printable soft nanocomposite hydrogels restoring magnetic hyperthermia responses

Hydrogels loaded with magnetic iron oxide nanoparticles that can be patterned and which controllably induce hyperthermic responses on AC-field stimulation are of interest as functional components of next-generation biomaterials. Formation of nanocomposite hydrogels is known to eliminate any Brownian contribution to hyperthermic response (reducing stimulated heating) while the Néel contribution can also be suppressed by inter-particle dipolar interactions arising from aggregation induced before or during gelation. We describe the ability of graphene oxide (GO) flakes to restore the hyperthermic efficiency of soft printable hydrogels formed using Pluronics F127 and PEGylated magnetic nanoflowers. Here, by varying the amount of GO in mixed nanocomposite suspensions and gels, we demonstrate GO-content dependent recovery of hyperthemic response in gels. This is due to progressively reduced inter-nanoflower interactions mediated by GO, which largely restore the dispersed-state Néel contribution to heating. We suggest that preferential association of GO with the hydrophobic F127 blocks increases the preponderance of cohesive interactions between the hydrophilic blocks and the PEGylated nanoflowers, promoting dispersion of the latter. Finally we demonstrate extrusion-based 3D printing with excellent print fidelity of the magnetically-responsive nanocomposites, for which the inclusion of GO provides significant improvement in the spatially-localized open-coil heating response, rendering the prints viable components for future cell stimulation and delivery applications.

Acupoint nanocomposite hydrogel for simulation of acupuncture and targeted delivery of triptolide against rheumatoid arthritis

BackgroundAttenuating inflammatory response and relieving pain are two therapeutic therapeutical goals for rheumatoid arthritis (RA). Anti-inflammatory and analgesic drugs are often associated with many adverse effects due to nonspecific distribution. New drug delivery systems with practical targeting ability and other complementary strategies urgently need to be explored. To achieve this goal, an acupoint drug delivery system that can target deliver anti-inflammatory drugs and simulate acupuncture in relieving pain was constructed, which can co-deliver triptolide (TP) and 2-chloro-N (6)-cyclopentyl adenosine (CCPA).ResultsWe have successfully demonstrated that acupoint nanocomposite hydrogel composed of TP-Human serum album nanoparticles (TP@HSA NPs) and CCPA could effectively treat RA. The result shows that CCPA-Gel can enhance analgesic effects specifically at the acupoint, while the mechanical and thermal pain threshold was 4.9 and 1.6 times compared with non-acupoint, respectively, and the nanocomposite gel further enhanced. Otherwise, the combination of acupoint and nanocomposite hydrogel exerted synergetic improvement of inflammation, bone erosion, and reduction of systemic toxicity. Furthermore, it could regulate inflammatory factors and restore the balance of Th17/Treg cells, which provided a novel and effective treatment strategy for RA. Interestingly, acupoint administration could improve the accumulation of the designed nanomedicine in arthritic paws (13.5% higher than those in non-acupoint at 48 h), which may explain the better therapeutic efficiency and low toxicity.ConclusionThis novel therapeutic approach-acupoint nanocomposite hydrogel, builds a bridge between acupuncture and drugs which sheds light on the combination of traditional and modern medicine.Graphical

Whole Three-Dimensional Dosimetry of Carbon Ion Beams with an MRI-Based Nanocomposite Fricke Gel Dosimeter Using Rapid T1 Mapping Method.

MRI-based gel dosimeters are attractive systems for the evaluation of complex dose distributions in radiotherapy. In particular, the nanocomposite Fricke gel dosimeter is one among a few dosimeters capable of accurately evaluating the dose distribution of heavy ion beams. In contrast, reduction of the scanning time is a challenging issue for the acquisition of three-dimensional volume data. In this study, we investigated a three-dimensional dose distribution measurement method for heavy ion beams using variable flip angle (VFA), which is expected to significantly reduce the MRI scanning time. Our findings clarified that the whole three-dimensional dose distribution could be evaluated within the conventional imaging time (20 min) and quality of one cross-section.

A green approach to the valorization of kraft lignin for the production of nanocomposite gels to control the release of fertilizer

AbstractThe valorization of industrial by‐products is a green approach. This work investigates the valorization of kraft liquor from paper pulping as a precursor in the production of lignin‐based nanocomposites to control the release of monoammonium phosphate (MAP) fertilizer. These nanocomposites were prepared from the stoichiometry of lignin nanoparticles (LNPs) and chitosan (Cs). The lignin nanoparticles were synthesized by solvent exchange and dialysis using two polar solvents: tetrahydrofuran (THF) and ethylene glycol (EG). These LNPs were characterized by transmission electron microscopy (TEM), X‐ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and textural techniques. The TEM images showed that the shapes of LNPs based on THF (LNPT) and LNPs based on EG (LNPE) were spherical, with an average particle size of 300 ± 40 nm and 23 ± 6.5 nm, respectively. Textural characteristics and FTIR revealed no change in the chemical nature of the two synthesized LNPs, and their Brunauer, Emmett and Teller (BET) surface area and average pore diameter ranged from 0.78 to 1.58 m2 g−1, and 4.069 to 5.20 nm, respectively. Swelling, functional groups, and the thermal, morphology, and MAP release characteristics were investigated for unloaded and loaded chitosan‐LNP nanocomposites (Cs‐LNPs). The water‐swelling capacity of the nanocomposite gel was about 200%. The data indicated that the Cs‐LNP gels can be used as controlled release systems for releasing MAP fertilizer, with maximum releasing value observed for chitosan‐LNPT gel (65%). The kinetic of MAP release from the investigated nanocomposites was followed by the Ritger‐Peppas model with Fickian and quasi‐Fickian diffusion mechanisms. © 2021 Society of Chemical Industry and John Wiley &amp; Sons, Ltd

Design, preparation and applications of gel nanocomposites from bile acids – A brief review

Synthesis of advanced hybrid materials formed by the unification of nanoparticles with gels is gaining importance due to their unusual properties coupled with the ease of fabrication. The gel medium provides a template for generating complex inorganic nanostructures with controlled size and desirable mechanical properties. In this paper, we review the synthesis of various inorganic nanoparticles in gel matrices formed by the self-assembly of bile acid-derived gelators and the role of the gel medium to improve the properties of the nanocomposites.