Sol-gel Approach Research Articles

Novel MnCo2O4/YVO4 heterostructure for promoting photocatalytic oxidative desulfurization of thiophene under visible light

In this work, for the first time, the photocatalytic oxidative desulfurizing of thiophene through exposure to visible light was performed on mesoporous MnCo2O4/YVO4 heterojunctions. Mesoporous YVO4 nanocrystals were combined with MnCo2O4 nanoparticles (NPs) to construct MnCo2O4/YVO4 heterostructure candidates using an easy sol-gel approach. The constructed mesoporous YVO4 with a tetragonal structure has a large surface area of approximately 200.0 m2 g−1. Within 90-min visible light exposure, the 9.0 wt% MnCo2O4/YVO4 nanocomposite photocatalyst exhibited 100.0 % desulfurization efficacy, which was ∼25.0 folds greater than occurred using the unmodified YVO4 (only 4.0 %). Notably, the 9.0 wt% MnCo2O4/YVO4 photocatalyst displayed a desulfurization rate of ca. 269.19 μmol L−1 min−1, which was ∼55.00 folds higher than that occurred on the unmodified YVO4 material (4.90 μmol L−1 min−1). The constructed MnCo2O4/YVO4 heterostructure exhibited preeminently superb photocatalytic thiophene oxidation with superior recyclability than nonmodified YVO4. The n-n heterojunction construction between MnCo2O4 and YVO4 played a major role in synergistic promoting the photocatalytic efficacy of the MnCo2O4/YVO4 nanocomposite through enlarging the photoabsorbance capability and promoting photoexcited carriers’ separation. Moreover, the abundant surface reactive sites originating from the mesoporous nature of the constructed heterostructure candidates significantly contributed to enhancing the photocatalytic thiophene oxidation. The 9.0 wt% MnCo2O4/YVO4 candidate exhibited high stability within 600.0 min. Overall, this contribution not only presents a new MnCo2O4/YVO4 heterojunction, fabricated by an easy approach for highly efficient desulfurizing of thiophene but also provides good ideas for establishing other heterostructure materials.

Effect of foreign impurity and growth temperatures on hexagonal structure and fundamental properties of ZnO nanorods.

This study examined the influence of growth temperature and dopant concentration on the properties of Gd- and Ni-doped zinc oxide nanorods (ZnO NRs). ZnO seed layers were deposited on glass substrates using a sol-gel and dip-coating approach. Gd- and Ni-doped ZnO NRs were hydrothermally grown on the seed layers at different temperatures such as 75, 90, and 105°C for a constant growth time of 5 h. The crystal structure, optical, surface morphology views, and electrical properties of the NRs were extensively investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible spectroscopy, and four probe experimental methods. The XRD analysis confirmed the successful substitution of Zn2+ ions by Gd3+ and Ni2+ within the ZnO main matrices. The reordering of hexagonal structures with varied electronegativity, ionic radius dimensions, and valence electron states of Gd and Ni dopants affected seriously the fundamental characteristic features of NRs. The SEM images showed that the ZnO NRs grown at 90°C possessed a more favorable surface morphology and well-defined hexagonal shape compared with those grown at other growth temperatures. Higher dopant concentration led to an increase in NR diameter but a decrease in density depending on the increase in the space between the NRs. Additionally, the optical transmittance was found to generally enhance with increasing dopant concentration. The results obtained highlighted the interplay between growth temperature, dopant type and concentration in tailoring the structural, morphological, and optical properties of Gd- and Ni-doped ZnO NRs, paving the way for the development of optimized nanomaterials for various applications. RESEARCH HIGHLIGHTS: The XRD analysis confirmed the successful substitution of Zn2+ ions by Gd3+ and Ni2+ within the ZnO main matrices. The SEM images showed that the ZnO NRs grown at 90°C possessed a more favorable surface morphology and well-defined hexagonal shape compared with those grown at other growth temperatures. The optical transmittance was found to generally enhance with increasing dopant concentration. The results obtained highlighted the interplay between growth temperature, dopant type and concentration in tailoring the structural, morphological, and optical properties of Gd- and Ni-doped ZnO NRs, paving the way for the development of optimized nanomaterials for various applications.

Photodegrading rhodamine B dye with cobalt ferrite-graphitic carbon nitride (CoFe2O4/g-C3N4) composite

The present research utilizes a sol-gel approach to create a CoFe2O4/g-C3N4 nanocomposite (NC) and explored several analytical methods to evaluate physical, chemical and optical based characteristics via XRD, FTIR, UV–vis, SEM/EDS and XPS for the prepared pure CoFe2O4, g-C3N4, and CoFe2O4/g-C3N4 NC. The XRD results show that the prepared g-C3N4, CoFe2O4, exhibits hexagonal and cubic phases respectively, whereas the g-C3N4/CoFe2O4 NC exhibit mixing of two phases. The energy band gaps for pure g-C3N4, CoFe2O4 and g-C3N4/CoFe2O4 NC values are viz., 2.75, 1.3, and 2.4 eV. As photocatalysts, synthesized materials were utilized for the decomposition of Rhodamine-B (RhB) dye. Finally, the CoFe2O4/g-C3N4 NC showed good performance of photocatalysis for RhB dye disintegration under the stimulus of visible light. According to the induced visible light, the rate at which the photocatalytic degradation occurs for the CoFe2O4/g-C3N4 NC was found to be 57% in 120 min and this is greater when compared with pure catalysts like CoFe2O4 (28%) and g-C3N4 (10%). These outcomes suggest that the prepared NC have efficiently worked during the photocatalytic process compared with its pure materials.

The effect of different temperature rate on sol-gel approach derived M-type hexagonal BaFe12O19 using D-mannose as a fuel: Synthesis, structural, thermal gravimetric and magnetic properties

In this article, we reported that the BaFe12O19 powders were prepared using the effective sol-gel process under different calcination temperatures, i.e., 700–900 °C for 2 h. The structural effects of the temperature rate on the phase formation, morphological and magnetic properties of the as-prepared powders have been analyzed and discussed. The X-ray diffraction pattern confirmed the hexaferrite phase formation at calcined temperature range of 800 °C with no secondary phase and the particles size are about 45 nm–65 nm. The Fourier-transform infrared (FT-IR) spectra show that the intensity frequencies for hexaferrite site stretching were observed at 601 and 443 cm−1 from Fe–O and Ba–O bonds, respectively. The micro-sized flakes morphological structure with particle sizes ranging from 45 to 65 nm by strongly agglomerated powders of the hexaferrite phase is examined through the field emission scanning electron microscopy (FESEM) technique for the good-quality calcined 800 °C. Additionally, the effect of the calcination rates at 800 °C on the material features was analyzed by the energy-dispersive X-ray, X-ray photoelectron spectroscopy (XPS), etc. The magnetic properties, such as saturation magnetization and coercive field of the as-prepared nanomaterials were analyzed using the vibrating sample magnetometry (VSM) technique. The hysteresis loop of the BaFe12O19 nanomaterials calcined at 800 °C for 2 h showed excellent magnetic properties, with a higher saturation magnetization curve of 55.774 emu/g and a coercivity (Hc) of 5079 kOe. The dark brown colored annealed 800 °C nanomaterials can be useful as a ceramic color pigment, which has several industrial applications.

Structural, electrical and magnetic studies on CoFe2O4 nanoparticles with polyvinylalcohol (PVA) via Sol-Gel approach

Cobalt ferrite (CoFe2O4) nanoparticles were synthesized using sol–gel method from cobalt nitrate; iron nitrate as precursor materials with the chelating agent PVA in water (2.5, 5.0, 7.5, 10.0 and 12.5 %) is added. Through X-ray diffraction (XRD) examinations, the crystallite size and single phase of the ferrite samples were studied. The functional and active analysis is found through Fourier transform infrared (FTIR) studies. The optical analysis carried out through UV–visible spectrometer and the absorption is found. The surface features and its content of elements were analyzed through SEM with EDAX analysis. The larger saturation magnetization at 12.5 % were recorded through vibrating sample magnetometer (VSM). The dielectric behavior recorded at room temperature from LCR measurement. The electrochemical behavior like V/I, impedance, scan rate and phase angle obtained through cyclic voltameter setup. The observed results with all the physical parameters with the influence of presence of PVA are discussed and interpreted extensively.

Rice husk-derived cobalt silica as effective peroxymonosulfate activator for degradation of organic pollutants

In this study, mesoporous silica was synthesized from rice husks, and subsequently used to prepare a cobalt silica (Co/SiO2) catalyst via a simple sol–gel approach. The synthesized Co/SiO2 catalyst was thoroughly characterized. The analysis of the scanning electron microscopy (SEM) images revealed silica particles with sizes of nearly 20 nm. Energy-dispersive X-ray analysis showed a good Co dispersion on the catalyst surface with a Co content of 7.7 %. The Co/SiO2 catalyst was then utilized as a peroxymonosulfate (PMS) activator to degrade reactive black 5 (RB5). Furthermore, the impact of various parameters on RB5 degradation was analyzed. The Co/SiO2 catalyst demonstrated excellent performance and completely degraded RB5 within 8 min with a rate constant of 5.5 × 10−1 min−1 at an extremely low dosage of 0.05 g/L. Furthermore, the degradation rate increased with temperature, and the activation energy was 51.5 kJ/mol. The analysis of the quenching and electron paramagnetic resonance experiments showed that SO4• −, HO•, 1O2, and O2• − were produced, with 1O2 being the predominant reactive species. Notably, the catalyst remained effective when tested in actual water environments and could degrade various other dyes and tetracycline. To facilitate catalyst recovery through filtration, Co/SiO2 was embedded in crosslinked chitosan beads. The bead catalyst demonstrated comparable performance to pristine Co/SiO2 and could be reused for five cycles.

Synthesize uniform ZrO2 NPs by non-coordination solvents and modification for high refractive film

Zirconia nanoparticles (ZrO2 NPs) are considered promising functional materials due to their high refractive index, thermal stability, and relatively wide bandgap. They can be particularly valuable when blended with monomer resins to create transparent composite materials with tunable refractive indices. However, the challenge of synthesizing uniformly sized and transparently dispersible ZrO2 NPs in organic resin monomers has been an ongoing research problem. In this study, we proposed an improved method based on an existing synthesis route for the production of ZrO2 NPs. We employed a sol-gel approach and introduced a simple yet effective strategy to synthesize ZrO2 NPs. Using high-boiling non-coordinating solvent squalane to adjust the concentration of oil amine ligands in the solution, helped to balance the nucleation and growth of ZrO2, thereby improving the size uniformity of ZrO2 NPs. In addition, the addition of sodium hydroxide (NaOH) to the reaction system effectively promoted the crystal growth of ZrO2 without affecting its crystal structure and crystallinity. Simultaneously, this addition significantly reduced the content of surface oleylamine (OAm) ligands. Finally, ZrO2 was modified using 2-Ethylhexanoic acid (EHA) and 3-methacryloxypropyltrimethoxysilane (KH-570), achieving successful transparent dispersion within the high refractive index acrylic monomer, benzyl acrylate (BZA). In-situ polymerization was used with a UV initiator to produce a refractive index continuously tunable BZA/ZrO2 composite film.

Advancements in the Synthesis and Functionalization of Zinc Oxide-Based Nanomaterials for Enhanced Oral Cancer Therapy.

The fabrication of zinc oxide-based nanomaterials (including natural and synthetic polymers like sulfated polysaccharide, chitosan, and polymethyl methacrylate) has potential to improve oral cancer treatment strategies. This comprehensive review explores the diverse synthesis methods employed to fabricate zinc oxide nanomaterials tailored for oral cancer applications. Several synthesis processes, particularly sol-gel, hydrothermal, and chemical vapor deposition approaches, are thoroughly studied, highlighting their advantages and limitations. The review also examines how synthesis parameters, such as precursor selection, the reaction temperature, and growth conditions, influence both the physicochemical attributes and biological efficacy of the resulting nanomaterials. Furthermore, recent advancements in surface functionalization and modification strategies targeted at improving the targeting specificity and pharmaceutical effectiveness of zinc oxide-based nanomaterials in oral cancer therapy are elucidated. Additionally, the review provides insights into the existing issues and prospective views in the field, emphasizing the need for further research to optimize synthesis methodologies and elucidate the mechanisms underlying the efficacy of zinc oxide-based nanoparticles in oral cancer therapy.

Cytotoxicity and heating efficiency of dendrimer functionalized graphene oxide modified nickel ferrite nanoparticles

Magnetic nanoparticles have garnered significant interest, offering a promising avenue for magnetic hyperthermia. In this study, nickel ferrite nanoparticles were successfully synthesized using green-mediated sol–gel approach and subsequently modified with graphene oxide and functionalized using G3 Polyamidoamine dendrimer. Saturation magnetization values obtained from VSM analysis were found to be 51.8 emu/g and 11.2 emu/g for bare and functionalized nickel ferrite nanoparticles, respectively. The functionalized nanostructure exhibited potential for hyperthermia applications, with a specific absorption rate of 16 W/g. The in-vitro cytotoxicity of the functionalized nickel ferrite nanoparticles shows cell viability of 94.55 %, underscoring the non-toxic nature of the functionalized material.

Impact of zinc oxide on dielectric properties of forsterite coated titanium based medical implants

Zinc oxide-doped forsterite solutions are synthesized through the sol-gel approach by varying the weight percentage of zinc oxide. These solutions are then applied to titanium (Ti) substrates to form zinc oxide-doped forsterite coated Ti substrate samples using the dip-coating method. The structural and surface morphology analyses of the samples are conducted using x-ray Diffraction (XRD) and Scanning Electron Microscope (SEM). Dielectric properties, encompassing dielectric constant, dielectric loss, alternating current conductivity, loss tangent, and relaxation time are explored at room temperature over a frequency range of 200 MHz to 20 GHz utilizing a Vector Network Analyzer (VNA) setup. The impact of zinc oxide on the structure, morphology, and dielectric properties of the samples, particularly in medical implant applications, is extensively discussed. The results indicate that samples with a higher weight percentage of zinc oxide demonstrate superior dielectric characteristics.

Synthesis of Mesoporous Silica Using the Sol-Gel Approach: Adjusting Architecture and Composition for Novel Applications.

The sol-gel chemistry of silica has long been used for manipulating the size, shape, and microstructure of mesoporous silica particles. This manipulation is performed in mild conditions through controlling the hydrolysis and condensation of silicon alkoxide. Compared to amorphous silica particles, the preparation of mesoporous silica, such as MCM-41, using the sol-gel approach offers several unique advantages in the fields of catalysis, medicament, and environment, due to its ordered mesoporous structure, high specific surface area, large pore volume, and easily functionalized surface. In this review, our primary focus is on the latest research related to the manipulation of mesoporous silica architectures using the sol-gel approach. We summarize various structures, including hollow, yolk-shell, multi-shelled hollow, Janus, nanotubular, and 2D membrane structures. Additionally, we survey sol-gel strategies involving the introduction of various functional elements onto the surface of mesoporous silica to enhance its performance. Furthermore, we outline the prospects and challenges associated with mesoporous silica featuring different structures and functions in promising applications, such as high-performance catalysis, biomedicine, wastewater treatment, and CO2 capture.

Fabrication of Rhenium Disulfide/Mesoporous Silica Core-Shell Nanoparticles for a pH-Responsive Drug Release and Combined Chemo-Photothermal Therapy.

A stimuli-responsive drug delivery nanocarrier with a core-shell structure combining photothermal therapy and chemotherapy for killing cancer cells was constructed in this study. The multifunctional nanocarrier ReS2@mSiO2-RhB entails an ReS2 hierarchical nanosphere coated with a fluorescent mesoporous silica shell. The three-dimensional hierarchical ReS2 nanostructure is capable of effectively absorbing near-infrared (NIR) light and converting it into heat. These ReS2 nanospheres were generated by a hydrothermal synthesis process leading to the self-assembly of few-layered ReS2 nanosheets. The mesoporous silica shell was further coated on the surface of the ReS2 nanospheres through a surfactant-templating sol-gel approach to provide accessible mesopores for drug uploading. A fluorescent dye (Rhodamine B) was covalently attached to silica precursors and incorporated during synthesis in the mesoporous silica walls toward conferring imaging capability to the nanocarrier. Doxorubicin (DOX), a known cancer drug, was used in a proof-of-concept study to assess the material's ability to function as a drug delivery carrier. While the silica pores are not capped, the drug molecule loading and release take advantage of the pH-governed electrostatic interactions between the drug and silica wall. The ReS2@mSiO2-RhB enabled a drug loading content as high as 19.83 mg/g doxorubicin. The ReS2@mSiO2-RhB-DOX nanocarrier's cumulative drug release rate at pH values that simulate physiological conditions showed significant pH responsiveness, reaching 59.8% at pH 6.8 and 98.5% and pH 5.5. The in vitro testing using HeLa cervical cancer cells proved that ReS2@mSiO2-RhB-DOX has a strong cancer eradication ability upon irradiation with an NIR laser owing to the combined drug delivery and photothermal effect. The results highlight the potential of ReS2@mSiO2-RhB nanoparticles for combined cancer therapy in the future.

Effect of electrolytes on supercapacitive behavior of cubic shaped pristine cuprous oxide synthesized via sol-gel approach

The present study uses the sol-gel approach to employ cuprous oxide (Cu2O) as an electrode material for the electrochemical energy storage application. Scanning electron microscopy (SEM) examines the structural and surface morphological characteristics of the synthesized material, and pure phase development is verified by the X-ray Diffraction (XRD) patterns. The synthesized material has a high value of specific capacitance, notable porosity, and a well-defined cubic shape. In the three-electrode set-up, the electrochemical analysis uses different aqueous electrolytes, i.e., KOH and NaOH. The electrochemical outcomes indicate that the synthesized material has a maximum specific capacitance (Cs) of 362.77 Fg-1 with excellent stability (104 %) in 6 M NaOH than KOH electrolyte (225 Fg-1). EIS data for Cu2O-based electrodes have been modeled using various equivalent circuits. The ESR value of Cu2O in NaOH electrolyte is much smaller (0.503 Ω) than in KOH electrolyte, indicating the creation of more active sites and enhanced accessibility of ions. Capacitive and diffusion current contributions are shown by using the Trassati and Dunn techniques. Thus, all our findings suggest that sol-gel synthesized pristine cuprous oxide is a potential option for energy storage gadgets.

ZnSnO3 - SnO2 nanocomposite as a catalyst for efficient hydrogen production through sodium borohydride methanolysis

In this work, we describe a straightforward modified sol gel approach for producing zinc stannate-tin oxide (ZnSnO3-SnO2) nanocomposite particles by combining tin chloride and zinc acetate using EDTA ammonium salt as an electrosteric inhibition agent. The acquired samples were characterized using simultaneous thermal gravimetric and differential scanning calorimetry (TGA/DSC), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-Vis spectroscopy and scanning electron microscopy (SEM). The catalyst activity of ZnSnO3-SnO2 particles in hydrogen production was determined by the methanolysis reaction from NaBH4. The hydrogen generation rate TOF (Turnover Frequency) The hydrogen generation rate, activation energy (Ea), enthalpy (ΔH) and entropy (ΔS) values of the hydrogen production reaction were calculated as 374.11 ml min−1.g−1 (832.38 h−1), 43.19 kJ mol−1, 40.65 kJ mol−1 and -178.96 J/mol.K, respectively. The prepared ZnSnO3-SnO2 composite can be recycled and used without obvious loss of activity; This makes the procedure economical and environmentally friendly.

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.

Preparation of AC/TiO2 doped N-Ce Synthesized via Microwave Irradiation for Amoxicillin Photodegradation

Activated carbon (AC) supported with titanium dioxide (TiO2) doped with nitrogen (N) and cerium (Ce), denoted as AC/TiO2 doped N-Ce was synthesized for adsorption and photodegradation of amoxicillin (AMX) antibiotic. Photocatalyst was prepared using sol-gel approach assisted by microwave irradiation.30 experiment runs were generated for photocatalyst production and optimized via Central Composite Design-Response Surface Methodology (CCD-RSM) with observation of four types of variable parameters. The experimental variables consisted of the quantities of urea (N) (𝑥𝑥𝑖𝑖: 0.02–0.20 g), amount of cerium (III) nitrate hexahydrate (Ce) (𝑥𝑥𝑗𝑗: 0.02–0.20 g), amount of AC (𝑥𝑥𝑘𝑘: 0.10 –0.50 g), and microwave power (𝑥𝑥𝑙𝑙: 600–800 W). The analysis revealed that AC/TiO2 doped N-Ce photocatalyst, which was prepared with 0.50 g AC, 0.02 g N, and 0.20 g Ce, and activated with microwave power 600 W in 15 min, achieved a 93.6% AMX removal under UV light irradiation. The photocatalyst was initially subjected to a concentration of 10 mg L-1 at 30 °Cfor a duration of 60 min.

Structural, optical, dielectric, and magnetic properties of Zn-doped copper ferrite—sol–gel approach

Structural, optical, dielectric, and magnetic properties of Zn-doped copper ferrite—sol–gel approach

Visible light-induced photocatalytic degradation of methylene blue dye using pure phase bismuth ferrite nanoparticles

The degradation of organic dyes in wastewater has become a significant environmental issue, requiring the development of degradation technologies that are both effective and environmentally friendly. The present study employed the sol-gel approach to synthesize nanoparticles of phase pure bismuth ferrite (BiFeO3). The nanoparticles were assessed for their ability to efficiently degrade methylene blue (MB) dye, especially under visible light irradiation. The X-ray diffractogram (XRD) confirmed the formation of BiFeO3 nanoparticles, with an average crystallite size of 48 nm. The material's band gap, with a value of 1.84 eV, demonstrates its capacity to effectively absorb light, including wavelengths within the visible spectrum. Scanning electron microscopy (SEM) was used to identify porous aggregated particles. Both Raman and Fourier transform infrared spectroscopy (FTIR) confirm the successful synthesis of pure BiFeO3 in the desired phase. The BiFeO3 photocatalyst exhibited a significant surface area and isotherms of type IV, a characteristic typically observed in mesoporous materials, as determined by the Brunauer-Emmett-Teller (BET) analysis. The efficacy of BiFeO3 nanoparticles in facilitating the decomposition of MB in a water-based solution was evaluated by visible light photocatalysis. An efficiency degradation of 98.49 % was recorded for MB within 2 h.

Research on Sol-Gel Synthesis of Low-Temperature Na2O-B2O3-SiO2 Vitrified Bonds and Preparation of High-Strength Stacked Abrasives Using the Molding and Crushing Method.

Currently, the sol-gel technique is employed in the synthesis of high-performance vitrified bonds; however, its application in the fabrication of stacked abrasives has been minimally explored. Furthermore, the methods utilized in the production of abrasive particles for stacked abrasives are technically challenging and incur high costs, which hinders their actual industrial application. Consequently, this study utilizes the sol-gel approach to synthesize a Na2O-B2O3-SiO2 ternary system vitrified bond powder and employs a molding and crushing method, which offers a lower technological barrier and reduced preparation costs, for the production of abrasive particles subsequently fabricating corundum stacked abrasives. Upon setting the binder composition to a molar ratio of n(SiO2):n(B2O3):n(Na2O) = 65:23:12, it was observed that the crystallization within the glass matrix was minimized and the optimal sintering temperature for the synthesized laminate abrasive to be sustained at 820 °C. At the aforementioned temperature, the binder melt is capable of flowing uniformly amongst the abrasive granules, thereby ensuring a robust encapsulation of the particles. The average single particle compressive strength of the prepared corundum stacked abrasive with a grain size of forty mesh can reach the highest of all composition points at 28.56 N and the average single particle compressive strength of the prepared diamond stacked abrasive is 28.14 N.

Ordered Mesoporous Silica Delivering siRNA as Cancer Nanotherapeutics: A Comprehensive Review.

Nanosized mesoporous silica has emerged as a promising flexible platform delivering siRNA for cancer treatment. This ordered mesoporous nanosized silica provides attractive features of well-defined and tunable porosity, structure, high payload, and multiple functionalizations for targeted delivery and increasing biocompatibility over other polymeric nanocarriers. Moreover, it also overcomes the lacunae associated with traditional administration of drugs. Chemically modified porous silica matrix efficiently entraps siRNA molecules and prevents their enzymatic degradation and premature release. This Review discusses the synthesis of silica using the sol-gel approach and the advantages with different silica mesostructure. Herein, the factors affecting the synthesis of silica at nanometer scale, shape, porosity and nanoparticle surface modification are also highlighted to attain the desired nanostructured silica carriers. Additional emphasis is given to chemically modified silica delivering siRNA, where the silica nanoparticle surface was modified with different chemical moieties such as amine modified with (3-aminoropyl) triethoxysilane, polyethylenimine, chitosan, poly(ethylene glycol), and cyclodextrin polymer modification to attain high therapeutic loading, improved dispersibility and biocompatibility. Upon systemic administration, ordered mesoporous nanosized silica encounters blood cells, immune cells, and organs mainly of the reticuloendothelial system (RES). Thereby, biocompatibility and biodistribution of silica based nanocarriers are deliberated to design principles for smart and efficacious nanostructured silica-siRNA carriers and their clinical trial status. This Review further reports the future scopes and challenges for developing silica nanomaterial as a promising siRNA delivery vehicle demanding FDA approval.