Functionalized Silica Nanoparticles Research Articles

Effects of Different Surface Functionalizations of Silica Nanoparticles on Mesenchymal Stem Cells.

Physicochemical properties of nanoparticles, such as particle size, surface charge, and particle shape, have a significant impact on cell activities. However, the effects of surface functionalization of nanoparticles with small chemical groups on stem cell behavior and function remain understudied. Herein, we incorporated different chemical functional groups (amino, DETA, hydroxyl, phosphate, and sulfonate with charges of +9.5, + 21.7, -14.1, -25.6, and -37.7, respectively) to the surface of inorganic silica nanoparticles. To trace their effects on mesenchymal stem cells (MSCs) of rat bone marrow, these functionalized silica nanoparticles were used to encapsulate Rhodamine B fluorophore dye. We found that surface functionalization with positively charged and short-chain chemical groups facilitates cell internalization and retention of nanoparticles in MSCs. The endocytic pathway differed among functionalized nanoparticles when tested with ion-channel inhibitors. Negatively charged nanoparticles mainly use lysosomal exocytosis to exit cells, while positively charged nanoparticles can undergo endosomal escape to avoid scavenging. The cytotoxic profiles of these functionalized silica nanoparticles are still within acceptable limits and tolerable. They exerted subtle effects on the actin cytoskeleton and migration ability. Last, phosphate-functionalized nanoparticles upregulate osteogenesis-related genes and induce osteoblast-like morphology, implying that it can direct MSCs lineage specification for bone tissue engineering. Our study provides insights into the rational design of biomaterials for effective drug delivery and regenerative medicine.

Modification of amino functionalized silica nanoparticles with L-proline and furanacrylic acid as novel composites for the efficient removal of methyl orange

The present study deals with the preparation of new composites in which L-proline (LP) and furnacrylic acid (FA) have been grafted on surface of amino functionalized silica nanoparticles (AFS). At first, AFS were prepared by sol-gel approach using tetraethoxysilane (TEOS) as silica source and aminopropyltriethoxysilane (APTES) as silica modifiers. Taking the advantage of amino group on AFS surface, LP and FA were easily grafted on silica surface to obtain LP grafted silica (AFS-LP) and FA grafted silica (AFS-FA) nanocomposites by post modification approach. As prepared composites were characterized by FTIR, SEM, XRD and TGA. The evidence of LP and FA on AFS was elucidated from the FTIR bands found at 1650–1698 cm−1 related to carbonyl group CO) of amide. Additionally, peaks observed at 2965 cm−1 (C-H stretching) of propyl groups and at 1050 cm−1 (Si-O-Si) indicated that the backbone of the material is preserved as silica. The micro images of SEM depicted that the AFS are spherical in shape and have more degree of monodispersivity whereas the SEM images of composites (AFS-LP and AFS-FA) have larger particle size and less degree of monodispersivity. Likewise, XRD peaks at 2θ (∼12°) revealed the mesoporosity of silica as well as hybrid silica and further depression in this peak in case of AFS-LP and AFS-FA depicted the existence of organic moieties on silica. TGA analysis depicted three decomposition steps (high weight loss) in case of AFS-LP and AFS-FA in contrast to two decomposition steps observed in case of AFS. The higher weight loss observed in the case of hybrid composites depicted the grafting of organic molecules on AFS. The prepared composites AFS-LP and AFS-FA were deployed to investigate their adsorption capacity to remove methyl orange (MO) from aqueous media. Experiments revealed that the composites have high adsorption capacity in acidic media (pH=2) with % removal of 85.05 % for AFS-LP and 81.70 % for AFS-FA. The experimental data was evaluated for adsorption isotherms and value of correlation factor (R2) was close to unity in case of Freundlich representing that the adsorption follows Freundlich isotherm. The data was also evaluated for kinetic models and higher values of R2 as well as closeness of experimental and calculated values of Qe predicted that adsorption of MO followed pseudo-second order kinetic model.

Facile Synthesis of Poly(methyl methacrylate) Silica Nanocomposite Monolith by In Situ Free Radical Polymerization of Methyl Methacrylate in the Presence of Functionalized Silica Nanoparticles.

Novel porous poly(methyl methacrylate) (PMMA) silica nanocomposites have been produced by utilization of polymerization-induced phase separation in a simple one-pot approach. A facile free radical polymerization of MMA in the presence of surface methacrylate-functionalized silica nanoparticles was carried out in ethanol-based solvents, successfully producing novel, morphologically designable porous nanocomposite monoliths. Differing from standard free radical polymerization in solution, a mixture of good and poor solvents (ethanol/N,N-dimethylformamide ratio) for the resulting polymer was used to trigger spinodal phase separation. The influence of monomer concentration, as well as solvent composition, on the morphology of the resulting porous polymers has been investigated. Porous monolith structures composed of connected particles and co-continuous morphologies were observed under a scanning electron microscope depending on the polymerization conditions. The resulting polymers were insoluble and showed swelling characteristics in some organic solvents that are capable of dissolving regular PMMA, indicating covalent bonds between the functionalized silica nanoparticles and the polymer chains. The presence of silica particles in the final polymer was proven via an ATR-IR analysis. The glass transition temperature of the present PMMA-silica nanocomposite was higher than that of the conventional PMMA. The porous polymer immersed in a mixed organic solvent showed coloration induced by the Christiansen effect.

Improved electrochemical sensor using functionalized silica nanoparticles (SiO2-APTES) for high selectivity detection of lead ions

Mesoporous silica nanoparticles, functionalized by APTES, were used to modify glassy carbon electrodes (GCE) and their performance was assessed for the accurate quantification of trace Pb2+ ions under electrochemical methods. Mesoporous (3-aminopropyl) triethoxysilane modified-silica particles (SiO2-APTES), of about 200 nm, were synthesized by the modified Stӧber method in presence of cetyltrimethylammonium bromide. Silica particles were characterized by X-Ray diffraction analysis, scanning electron microscopy, infrared spectrum analysis, and electrochemical techniques such as cyclic voltammetry and electrochemical impedance spectroscopy (EIS). Furthermore, their mesoporous characteristics were investigated by the analysis of N2 adsorption/desorption isotherms. The functional groups on the silica particle surface showed remarkable selectivity towards Pb2+. Various experimental parameters, including incubation time, pH of the buffered solution, and quantity of SiO2-APTES deposited on the electrode were systematically investigated to identify optimal operating conditions for the system. After optimization, the sensors covered a working dynamic range from 8.8 × 10−8 M to 1.2 × 10−6 M achieving a noteworthy limit of detection of 2.6 × 10−8 M. Interference studies have demonstrated that GCE/SiO2-APTES electrodes exhibit high sensitivity and specificity for Pb2+ detection, making them a promising tool for rapid and portable detection of this heavy metal. Finally, the feasibility of these electrodes for Pb2+ ions detection was evaluated in real samples such as seawater (obtained from Monastir, Tunisia) and tap water by using the standard addition method. The high accuracy and reliability of the SiO2-APTES modified GCE was demonstrated by the excellent recovery studies, which ranged from 88 to 104% for all spiked samples. The overall finding supports the practical applicability of this sensor for a real-world context and confirms its potential for environmental monitoring.

Differential Silica Nanoparticles Functionalized with Branched Poly(1-Vinyl-1,2,4-Triazole): Antibacterial, Antifungal, and Cytotoxic Qualities

This research aims to improve antimicrobial materials based on functional silica nanoparticles. Three different methods were used in the study to create silica nanoparticles with other properties. The nanoparticles’ morphological structures are porous, hollow, and filled with spherical forms. The surface of these nanoparticles was grafted with poly(1-vinyl-1,2,4-triazole) (PVTri). The morphological properties of nanocomposites were used for analysis. In contrast, thermal gravimetric analysis was used to characterize the thermal properties of nanocomposites (thermogravimetric analysis). The silica nanoparticles were evaluated for their in vitro antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Saccharomyces cerevisiae using minimum inhibitory concentration measurement. Silica nanoparticles have different antifungal and antibacterial properties related to their structure. The cytotoxic effects of the silica nanoparticles on HaCaT cells were performed with an MTS assay. In this study, we observed that high doses of HSS and e-SiO2 decreased cell growth, while HSS and e-SiO2 composite with PVTri increased cell proliferation.

Composite nano hydrogel with dual response and hierarchical drug release for enhanced wound healing

A novel nanocomposite hydrogel with photothermal therapeutic properties, which could enhance the healing of surgical wounds, was developed. The composite comprises functionalized silica nanoparticles (FSNs) loaded with desferoxamine (DFO) as the core and a dexamethasone (Dex) filled hyaluronic acid–chitosan hydrogel (HA-CS) as the shell. Dex can effectively control inflammation at the wound site, and DFO is beneficial in proliferating the skin cells. The two drugs effectively promote wound healing at the surgical site. The aim of this approach is to demonstrate the hierarchical and continuous release of Dex and DFO from the FSNs@DFO-H@Dex system to reduce wound inflammation and promote healing. Furthermore, the controlled release of DFO can be achieved by controlling the near-infrared illumination. The composite nano hydrogel has a photothermal response, which accelerates wound healing by effectively reducing inflammation through the controlled release of drugs and regulating the immunological response of damaged skin tissue.

Bioaccessibility of chlorogenic acid and curcumin co-encapsulated in double emulsions with the inner interface stabilized by functionalized silica nanoparticles

The aim of this study was to evaluate the bioaccessibility of chlorogenic acid (CA) and curcumin co-encapsulated in Pickering double emulsions (DEs) with the inner interface stabilized by hydrophobically modified silica nanoparticles with myristic acid (SNPs-C14) or tocopherol succinate (SNPs-TS). Both SNPs-C14 and SNPs-TS showed contact angles > 90°. Pickering W1/O emulsions were formulated with 4 % of both types of SNPs. Pickering DEs showed higher creaming stability (5–7 %, day 42) and higher CA encapsulation efficiency (EE; 80 %) than control DE. The EE of curcumin was > 98 % in all the DEs. CA was steadily released from Pickering DEs during digestion, achieving bioaccessibility values of 58–60 %. Curcumin was released during the intestinal phase (∼80 % bioaccessibility in all DEs). Co-loaded DEs showed similar bioaccessibility for CA and curcumin than single-loaded. SNPs-C14 and SNPs-TS were suitable to stabilize the W1:O interface of DEs as co-delivery systems of bioactive compounds with health-promoting properties.

Development of amine-functionalized fluorescent silica nanoparticles from coal fly ash as a sustainable source for nanofertilizer

Scaling up the synthesis of fluorescent silica nanoparticles to meet the current demand in diverse applications involves technological limitations. The present study relates to the hydrothermal synthesis of water-soluble, crystalline, blue-emitting amine-functionalized silica nanoparticles from coal fly ash sustainably and economically. This study used tertiary amine (trimethylamine) to prepare amine-functionalized fluorescent silica nanoparticles, enhancing fluorescence quantum yield and nitrogen content for nanofertilizer application. The TEM and FESEM studies show that the silica nanoparticles have a spherical morphology with an average diameter of 4.0 nm. The x-ray photoelectron and Fourier transform infrared spectroscopy studies reveal the presence of the amine group at the surface of silica nanoparticles. The silica nanoparticles exhibit blue fluorescence with an emission maximum of 454 nm at 370 nm excitation and show excitation-dependent emission properties in the aqueous medium. With the perfect spectral overlap between silica nanoparticle emission (donor) and chlorophyll absorption (acceptor), fluorescent silica nanoparticles enhance plant photosynthesis rate by resonance energy transfer. This process accelerates the photosynthesis rate to improve the individual plant’s quality and growth. These findings suggested that the fly ash-derived functionalized silica nanoparticles could be employed as nanofertilizers and novel delivery agents.

Diffusion of Water Molecules on the Surface of Silica Nanoparticles─Insights from Nuclear Magnetic Resonance Relaxometry.

1H spin-lattice nuclear magnetic resonance (NMR) relaxation experiments have been performed for water dispersions of functionalized silica nanoparticles of diameters of 25 and 45 nm. The experiments have been performed in a broad frequency range spanning 3 orders of magnitude, from 10 kHz to 10 MHz, versus temperature, from 313 to 263 K. On the basis of the data, two-dimensional translation diffusion (diffusion close to the nanoparticle surface within a layer of the order of a few diameters of water molecules) has been revealed. The translational correlation times as well as the residence life times on the nanoparticle surface have been determined. It has turned out that the residence lifetime is temperature-independent and is on the order of 5 × 10-6 s for the smaller nanoparticles and by about a factor of 3 longer for the larger ones. The translational correlation time for the case of 25 nm nanoparticles is also temperature-independent and yields about 6 × 10-7 s, while for the dispersion of the larger nanoparticles, the correlation times changed from about 8 × 10-7 s at 313 K to about 1.2 × 10-6 s at 263 K. In addition to the quantitative characterization of the two-dimensional translation diffusion, correlation times associated with bound water molecules have been determined. The studies have also given insights into the population of the bound and diffusing water on the surface water fractions.

Development of a prototype of a theranostic system based on silica nanoparticles with immobilized fluorescent dyes and VEGF targeting ligand.

Background. Administration of certain drugs causes undesirable effects associated with the systemic effect of the active substance on the entire body. Selective targeting of the drug to the affected tissue promotes a selective increase in the concentration of the substance in the area of interest, thereby reducing the systemic effect and enhancing the local therapeutic effect.Objective. Development of a targeted delivery system for theranostic agents using recombinant human vascular endothelial growth factor type A (rhVEGF-A121) as a targeting ligand.Design and method. To create the theranostic complex, commercially available reagents were used: the recombinant protein rhVEGF-A121 (cat.#: PSG140-10, LLC CyStorLab, Skolkovo, Russia) and fumed silica Aerosil (A-200, Degussa AG, Germany). The tosyl spacer that interconnects both components was synthesized in the laboratory. Protein conjugation with fluorophores was also carried out in-house. Indocyanine green (ICG; Sigma-Aldrich, USA) and rhodamine B (JSC Lenreaktiv, St. Petersburg, Russia) were taken for immobilization.Results. In the course of the work, functionalization of silica nanoparticles (SiNPs) with a tosyl spacer was carried out, conjugates of SiNPs with rhVEGF-A121 were synthesized, and theranostic constructs based on SiNPs were obtained, including rhVEGF-A121 as a targeting ligand, and ICG/Rhodamine B as a visualizing label.Conclusion. In the presented study, a prototype of a complex for targeted delivery of a theranostic agent to tissues with an active angiogenesis process, for example, to tumor and ischemic tissues, was developed. To solve the problem, we immobilized on the surface of SiNP a recombinant protein of human vascular endothelial growth factor (rhVEGF) to use as a guide ligand. Such a synthetic construct will help to deliver diagnostic and/ or medicinal substances packed in SiNP directly to cells that overexpress extracellular specific receptors of the VEGFR family. In subsequent in vivo experiments, delivery efficiency will be assessed by tissue accumulation of the fluorophores ICG and rhodamine B, which have been conjugated to the targeting ligand protein. The physicochemical characteristics of the obtained samples were studied by the methods of spectrophotometry and dynamic light scattering.

Functionalized borosilicate-silica-epoxy nanocomposite superhydrophobic coating for corrosion inhibition under harsh environment

Current work proposes a facile scheme for fabrication of robust superhydrophobic borosilicate-silica-epoxy nanocomposite coatings on steel substrate with hierarchical structures, capable of inhibiting corrosion under harsh environment. The scheme amalgamates the advantageous properties of three ingredients: acid resistant property of borosilicate glass, superhydrophobic features of functionalized silica nanoparticles and durability of epoxy resin. The various steps of synthesis include 1. ball milling of borosilicate glass to micron and submicron size (~500 nm to 1.5 μm) 2. grafting of silica nanoparticles (~20 nm, through stober method) on the borosilicate particles to form rough hierarchical structure and 3. preparation of stable dispersion of the nanoparticles in epoxy-based resin followed by coating through immersion technique. Efficacy of the scheme was established through morphological, durability and electrochemical impedance studies. The surface morphology revealed hierarchical structures of functionalized silica nanoparticles (size range 20–100 nm) grafted on micro-sized borosilicate particles, which sustained water droplets with contact angle as high as 164.5° ± 2°. Sandpaper abrasion test proved excellent durability retaining hydrophobicity up to 250 abrasion cycles. The prepared surface maintained notable interface stability under aggressive environment: 3 and 10 days under pH 1 and 13 respectively. The electrochemical study in 3.5 wt% NaCl aqueous solution showed significant decrease in corrosion current density of coated surface (0.3585 μA/cm2) compared to uncoated surface (43.918 μA/cm2) suggesting excellent corrosion resistance. The results highlight scope of using this robust coating for abrasive and harsh environment.

Highly CO2-Selective Membranes Composed of Quaternary Ammonium Functionalized Silica Nanoparticles

Highly CO₂-Selective Membranes Composed of Quaternary Ammonium Functionalized Silica Nanoparticles

Benzimidazole-modified organosilane functionalized silica nanoparticles as a ‘turn-off’ fluorescent probe for highly selective Cu2+ ion detection: unravelling logic gate behaviour and molecular docking studies

The present work involves the synthesis of a new benzimidazole derived organosilane and its hybrid silica nanoparticles for the recognition of Cu2+ ions and this nanocomposite demonstrated a strong affinity for Cu2+ ions.

The preparation of a boronate affinity-based controlled oriented imprinting coating on a silica nanoparticle surface for the separation and purification of shikimic acid in herbal medicine.

Shikimic acid (SA) is one of the most effective drugs against the A (H1N1) virus and has high medicinal value. Additionally, it has the ability to generate non-toxic herbicides and antimicrobial medications. The extraction from plants has proven to be the main route of production of SA with economic benefits and environmental efficiency. Therefore, it is necessary to perform purification of SA from these herbal medicines before quantifying it. In this study, researchers employed a boronate affinity-based controlled oriented surface imprinting technique to produce molecularly imprinted polymers (MIPs) as highly effective solid phase extraction (SPE) adsorbents for the isolation and purification of SA. 3-Fluoro-4-formylphenylboronic acid functionalized silica nanoparticles were used as supporting materials for immobilizing SA. Poly(2-anilinoethanol) with a higher hydrophilic domain can be used as an effective imprinting coating. The prepared SA-imprinted silica nanoparticles exhibited several significant results, such as good specificity, high binding capacity (39.06 ± 2.24 mg g-1), moderate binding constant (6.61 × 10-4 M-1), fast kinetics (8 min) and low binding pH (pH 5.0) toward SA. The replication of SA-imprinted silica nanoparticles was deemed satisfactory. The SA-imprinted silica nanoparticles could be still reused after seven adsorption-desorption cycles, which indicated high chemical stability. In addition, the recoveries of the proposed method for SA at three spiked level analysis in star aniseed and meadow cranesbill were 96.2% to 109.0% and 91.6% to 103.5%, respectively. The SA-imprinted silica nanoparticles that have been prepared are capable of identifying the target SA in real herbal medicines. Our approach makes sample pre-preparation simple, fast, selective and efficient.

Salinity stress and different types of nano silicon's effects on lupine morphology and biochemical accumulations

Drug and food industries employ lupine (Lupinus termis). Saline irrigation water is one of the main obstacles to spread of lupine growing in Egypt's reclamation regions. Productivity of plants grown under salty irrigation water can be improved by using silicon nanoparticles (SiNPs) or functionalized silica nanoparticles (FSiNPs). Lupine plant can be harmed by saline water, especially if it includes sodium chloride; consequently, it was projected that lupine production would fail in Egypt's reclaimed soil, where sodium chloride-containing groundwater is used as the principal irrigation source. In this work, Si types were applied to the leaves of lupine to aid in their response to sodium chloride in to lessen the damaging effects of sodium chloride on them for increasing their output in the recently reclaimed regions. Si types were applied to lupine leaves at 0, 1, 2 mM SiNPs, and 1, 2 mM FSiNPs with fresh or saline water. Obtained results indicated that there were different improvements in the morphological characters, yield and fixed oil content, when SiNPs or FSiNPs were applied to lupine plants that had been exposed to saline water. In this way, SiNPs or FSiNPs adapted to saline water by increasing photosynthetic pigments (chlorophyll a or b and carotenoids), osmolytes (proline, soluble sugars, free amino acids), antioxidant molecules (phenols and flavonoids), membrane stability index and antioxidant enzymes (catalase, superoxide dismutase, peroxidase and glutathione reductase), while decreasing the values of hydrogen peroxide, malondialdehyde and electrolyte leakage. However, additions of FSiNPs under saline water performed better than SiNPs x saline water treatments. This study assists farmers in reducing the negative impacts of saline irrigation water on reclaimed fields.

EGFR-targeted humanized single chain antibody fragment functionalized silica nanoparticles for precision therapy of cancer

The combination of highly specific targeting ability and potent killing effect has made antibody-drug conjugates (ADCs) a popular area of focus in the development of anti-cancer drugs. However, the large molecular weight of IgG antibodies (∼ 150 kDa) often faces challenges in penetrating capillaries and stroma in tumor tissue. Moreover, when the drug-antibody ratio (DAR) is too low (DAR < 2) or too high (DAR > 6) it decreases the effectiveness of the ADC and further increases the potential for aggregation, overall clearance of the early system payload, and release rate. In this study, an EGFR-based single-chain antibody fragment (husA)-human serum albumin (HSA)-coupled FITC-labeled mesoporous silica nanoparticle (FMSN-DOX-H-husA) was developed. Chinese hamster ovarian cells express the husA, which is a single chain antibody fragment of the EGFR that has been humanized. The small molecular weight of the single chain antibody allows for shorter penetration into solid tumors and the absence of adverse effects of the Fc fragment. The modification of HSA improves the safety of the antibody nanoparticle couples by both improving the biocompatibility of the nanoparticles, prolonging the circulation time of the nanoparticles, and avoiding early release of the payload. Also, the humanization substantially reduces the immunogenicity. More importantly, the ratio of drug antibodies on nanoparticles was experimentally and computationally derived to be 11.8, providing a more accurate guide for clinical trials. The results of both in vivo and in vitro experiments indicated promising antitumor activity and safety of FMSN-DOX-H-husA. Thus, this antibody-drug conjugate provided a hopeful option for cancer treatment.

Effect of nanomaterials functionality on the acidic crude oil: Wettability and oil recovery studies

Chemical enhanced oil recovery often involves the injection of chemicals, such as surfactants, polymers, nanoparticles, and macromolecules. These chemicals are to alter the rock-oil-water interactions and mobilize the oil towards the production well. However, they often pose considerable challenges in the harsh environment of the oil-wet reservoirs, such as chemical instability, and high retention/adsorption of chemicals in the near-wellbore. Herein, we investigated the effect of functionalized silica nanofluids on improving oil recovery in the carbonate reservoir as a function of the oil acidity. To do so, we synthesized two types of silica nanofluids functionalized with sulfonate and carboxylate groups. We used two crude oils with different total acid numbers (TAN) of 0.4 and 5.7 mg/KOH. All experiments were ran at 100 °C and salinity of 67–240 kppm to simulate the harsh reservoir conditions of the Saudi Arabia. Spontaneous imbibition oil recovery studies were conducted to assess their effects on oil recovery. Contact angle and interfacial tension were performed at different conditions to examine the oil recovery mechanism. Further, in order to corroborate the previous research and comprehend the principles underlying the oil recovery, we also examined the electrokinetic zeta potential in parallel. Also, to better understand how oil and nanofluid functional groups interact, we conducted a surface complexation model study. In addition, molecular simulation (density functional theory and molecular dynamics) are employed to gain atomistic insights on the implicated molecular interactions between nanosilica particles with calcite surface in seawater brine. DFT simulations predicted that both functionalized nanosilica can form thermodynamically stable complexes with a dry and hydrated calcite surface. Further, MD simulations reveal that a good amount of both functionalized nanosilica are interacting with calcite surface in the diffuse electric double layer of the calcite-brine interface. However, the carboxylated functionalized nanosilica particles interact with rock stronger than sulfonated ones. Further, the carboxylated nanosilica could form stable complexes with naphthenic acids mediated by calcium ions, which supports the synergy effect observed experimentally. The results shed light on much more complex mechanisms behind the oil recovery rather than the common peripheral understanding. This work provides a good insight into the applicability of nanofluids for enhanced oil recovery for further research and field trials.

Polyacrylic acid tethered onto the surface of vinyl functionalized silica nanoparticles for flexible hydrogel electrolytes of sodium ion hybrid supercapacitors

Hydrogel electrolytes, where water solvents and salts are confined in the porous networks of polymeric or inorganic solids, are attractive because they can resolve technical challenges of liquid electrolytes such as leakage, water decomposition, and mechanical instability. Herein, we demonstrate polyacrylic acid tethered onto the surface of vinyl functionalized silica nanoparticles (PAA-VSNP) hydrogel electrolytes through a sol-gel and radical polymerization process. The synthesis chemistry, the associated chemical structure, and the morphology of PAA-VSNP hydrogel electrolytes were comprehensively characterized analyzing FTIR, XPS and 13C and 29Si solid-state MAS NMR spectroscopies. The resulting PAA-VSNP hydrogel electrolytes were mechanically stable as verified by the stretchability up to 1122.75% of original length as well as ionically conductive as demonstrated by higher ionic conductivity of 20.23 mS cm−1 and lower activation energy of 0.106 eV than those of PVA counterparts. Integrating this PAA-VSNP hydrogel electrolytes with activated carbon and Na3V2(PO4)3/carbon composite and, flexible sodium ion hybrid supercapacitors (AC//PAA-VSNP //NVP@C SHSC SHSC) full cells could be fabricated. The as-fabricated AC//PAA-VSNP//NVP@C SHSC achieved a long-term cyclability over 4000 cycles and flexibility, delivering the larger energy and power densities 86.95 W h kg−1 and 19.94 kW kg−1 than those of AC//PVA//NVP@C and other works using hydrogel electrolytes.

A new solid phase extraction sorbent developed based on cyanopropyl functionalized silica nanoparticles for organophosphorus pesticides determination

In this work, a simple sol-gel approach was used for the preparation of cyanopropyl (CNPr) functionalized silica nanoparticles (SiO2-CNPr) that tetraethoxysilane (TEOS) and cyanopropyltriethoxysilane (CNPrTEOS) used as precursors. This as-prepared SiO2-CNPr nanoparticle sorbent was first characterized using FESEM, EDX, FTIR, TGA, and BET techniques. Then, the SiO2-CNPr nanoparticle was applied as a new SPE sorbent for determining trace levels of OPPs in environmental water samples. To enhance the simultaneous extraction of non-polar or/and polar OPPs and to obtain the most efficient sorbent, several sol-gel synthesis parameters were studied. In addition, the effect of several effective parameters on SPE performance was investigated toward simultaneous extraction of non-polar or/and polar OPPs. Moreover, the figures of merit such as precision, linearity, LOQ, LOD, and recovery were evaluated for the sorbent. Finally, the designed SiO2-CNPr SPE was used to determine OPPs in real water samples, and its extraction performance was compared to commercial cartridges based on cyanopropyl.

Reprocessable Non-Isocyanate Polyurethane Vitrimers

Non-isocyanate polyurethanes (NIPUs, polyhydroxyurethanes, PHUs), have emerged as sustainable alternatives to conventional isocyanate-polyol polyurethanes. However, the permanent cross-links in traditional linear, crosslinked polyhydroxyurethane polymer networks hinder their recyclability for high-value applications. In this study, we provide a comprehensive overview of polyhydroxyurethane vitrimers – polymers with intrinsic recyclability – containing dynamic covalent adaptable bonds that allow them to be reprocessed or self-healed under external stimuli such as heat or solvents. These materials exhibit a unique combination of the attributes of thermosets, such as improved heat stability, solvent resistance or enhanced mechanical properties, and the reprocessability of thermoplastics. Various strategies have been explored to enable the reprocessability of PHUs. External catalysts, such as 4-(dimethylamino)pyridine (DMAP) have been used to facilitate exchange reactions and promote reprocessing. Additionally, the use of functionalized silica nanoparticles as reinforcing fillers has influenced the material’s behavior during reprocessing. Another method involved the incorporation of dynamic disulfide bonds to expedite reprocessing times for PHU networks, while dissociative dynamic chemistry has enabled self-healing behavior in certain partially cross-linked NIPUs. These advancements demonstrate the potential for tailoring the reprocessability and mechanical attributes of NIPUs, paving the way for sustainable and versatile polymeric materials, and addressing the environmental concerns associated with traditional polyurethanes.