3-aminopropyltriethoxysilane Research Articles

Silica Janus Particle-Based Coating Applicable to Multiple Substrates Shows Durable Superhydrophobicity, Wear Resistance, and Corrosion Inhibition.

The present work reports the fabrication of a durable superhydrophobic coating based on silica Janus particles. One side of the silica particles was modified by (3-aminopropyl)triethoxysilane to have a reactive alkylamine group, and the other side was treated with octadecyltrimethoxysilane to be hydrophobic. These Janus particles were held together by binder molecules that reacted with the amines attached to the Janus particles and adhered to different substrates, forming superhydrophobic coatings. The water contact angles of the coatings were higher than 158°, whereas their sliding angles were as low as 2°. Their hydrophobicity was preserved even after 200 cycles of intensive abrasion or after 60 days of immersion in 3.5% NaCl solution, evidencing their durable resistance to abrasion and corrosion. The most remarkable property of the presented Janus silica particle-based coating is that it can strongly adhere to multiple substrates such as active metal aluminum, flat substrate glass, biological material wood, and organic polymer with low surface energy polyperfluoroethylene. Moreover, the hydrophobicity, antiwear resistance, and corrosion inhibition ability of the fabricated coating were independent of the substrates. This superiority enables this coating to cover many substrates with different surface properties to fulfill a variety of technical demands.

Uremic Toxins Elimination from Simulated Intestinal Serum with Mesoporous Silica Nanoparticles Coupled with Molecularly Imprinted Polymers and Amino Linker

Background: One of the most researched issues is the elimination of uremic toxins from the human body. These toxins can build up and lead to catastrophic issues including renal failure. To get rid of them, absorbents like activated carbon, zeolites, and other minerals are frequently utilized. Methods: Mesoporous silica nanoparticles functionalized with (3-Aminopropyl) triethoxysilane (APTES) linker (MSN-NH2) and mesoporous silica nanoparticles grafted with molecularly imprinted polymers (MSN-MIP) from the previous study were examined in this study to determine how well they absorbed urea, creatinine, and uric acid in a simulated intestinal serum. Results: MSN-MIP's large surface area (879.12 (m2/g)) and volume of pores (0.8475 (cm3/g)) made removal results that were satisfactory in the simulated serum. Additionally, MSN-MIP demonstrated a high urea adsorption capacity (qm = 1836.45 mg/g). Creatinine (qm = 1529.5 mg/g) and uric acid (qm = 1210.6 mg/g) were absorbed via NH-MSN2, which demonstrated a noticeable potential for absorption. The results of cell viability test for the first 72 hours, showed that the use of these absorbents in hemodialysis systems is acceptable. Conclusion: Synthesized adsorbents can be utilized in the hemodialysis system since the results of the cell viability test also showed that the percentage of cell viability was extremely high up to 72 hours.

A promising CO2 methanation catalyst system based on modified halloysites as supports

Abstract Earth’s climate is warming due to anthropogenic emissions of greenhouse gases, especially carbon dioxide (CO2). Different reactions are allocated to mitigate the CO2 in the atmosphere. However, CO2 methanation is a pivotal research hotspot due to its ability to produce methane at low operating temperatures (200–400 °C). Halloysite nanotubes (HNTs)-based catalysts have attracted significant attention in various catalytic applications. However, Halloysite is rarely reported for thermal CO2 methanation. The selected halloysite clay was modified first using the 3-Aminopropyl triethoxy silane (NH2) as coupling agent, the resulting materials (HNTs), and then doped with Ni at different weight concentrations (5%, 10%, 20%, 40%, 50%). materials can offer high surface area and porous structure, which can improve metal dispersion. The prepared Ni/HNTs catalysts were characterized using various techniques, such as XRD, XPS, SEM, and TEM, which confirmed the existence of nanotubes and porous structures. The propensity of the prepared Ni/HNTs were evaluated to catalyse the CO2 methanation reactions at a temperature range of 250 to 500 ̊C. The catalyst containing 20 wt.% of Ni (20Ni/HNTs) showed the highest CO2 conversion at all reaction temperatures and the highest selectivity of methane at 450 °C (82%). This study paves the way for the large utilization of the HNTs as a strong support for different metals used in thermal catalytic reactions, not limited to the CO2 methanation. Graphical Abstract

Fabrication of a poly(m‑aminophenol)/3-aminopropyl triethoxysilane/graphene oxide ternary nanocomposite for removal of Cu(II) from aqueous solution

Three composites based on Poly (meta-aminophenol) (PmAP), (3-aminopropyl) triethoxysilane (APTES) and graphene oxide (GO) were synthesized with initial GO dispersion of 3.3, 6.6, and 9.9 mg/mL. First, in-situ polymerization of meta-aminophenol monomer on the surface of graphene oxide (GO) was carried out. Then, the hydroxyl groups of both the GO and the polymer were targeted using (3-aminopropyl) triethoxysilane (APTES) to stop the polymer solubility, increase adsorption sites, and bind the two components. The obtained three composites were applied for efficient removal of Cu(II) from polluted water. PmAP/APTES/GO(6.6) composite was the best one for the uptake of Cu(II) with a maximum adsorption capacity of 324.54 mg/g at 40 °C and pH 7 according to Langmuir. PmAP/APTES/GO(6.6) hybrid composite was characterized by different techniques. The adsorption of Cu(II) on this composite was optimized under various experimental conditions. Furthermore, the isotherm data of the uptake of Cu(II) on PmAP/APTES/GO(6.6) were found to agree with the Freundlich and Langmuir model’s linear and nonlinear forms. Chemosorption was suggested by the Dubinin-Radushkevich (D-R) isotherm model as the calculated mean sorption energy exceeds 16 kJ/mol. The thermodynamic analysis of the adsorption process reflects an endothermic, spontaneous process that leads to more disorder at the solid-liquid interface. The chemical interactions between Cu(II) versus oxygen and nitrogen of the functional groups on the surface were demonstrated by X-ray Electron Spectroscopy (XPS). Five cycles of adsorption and desorption of Cu(II) from the prepared composite were carried out with a loss of only 6.3% of its adsorption capacity.

Enhancing the Rheological and Filtration Performance of Water-Based Drilling Fluids Using Silane-Coated Aluminum Oxide NPs.

For optimizing the drilling efficiency, nanoparticles (NPs) specifically nanometal oxides have been used in water-based drilling fluids (WBDF). Nano metal oxides improve the rheological and filtration characteristics of the WBDF. However, dispersion instability among pristine nano metals shrinks the performance of the nanometal oxides due to high surface energy. Therefore, this study aims to utilize silane-coated aluminum oxide NPs (S-Al2O3) as an alternative to widely used pristine aluminum oxide (P-Al2O3) in water-based drilling fluids. The S-Al2O3 NPs were synthesized using 3-aminopropyl triethoxysilane (APTES). FTIR, XRD, and SEM analyses were carried out to examine the crystalline structure and surface morphology of NPs. Moreover, the rheological and filtration properties of nanowater-based drilling fluids were investigated at low-pressure and low-temperature (LPLT) conditions. The results of experiments revealed that S-Al2O3 NPs significantly upgraded the rheological properties compared to P-Al2O3 NPs. The S-Al2O3 NPs reduced plastic viscosity from 12.6 to 9.6 cP, apparent viscosity from 34.5 to 26.5 cP, and yield point from 46.5 to 39.5 lb/100 ft2. The gel strengths (10 s and 10 min) were reduced from 44.5 to 32 lb/100 ft2 and from 77 to 59 lb/100 ft2, respectively. Furthermore, S-Al2O3 NPs enhanced the filtration performance, achieving a 26% reduction in filtrate loss and forming a thinner, more impermeable mud cake than P-Al2O3 NPs. In conclusion, the application of S-Al2O3 NPs in water-based drilling fluid was found to be effective in improving the rheological properties and controlling the filtrate loss effectively under LPLT conditions. The utilization of silane-coated NPs used in this study will open new and novel doors of research in the fields of both drilling engineering and nanotechnology.

Design and Synthesis of Phthalocyanine-Sensitized Titanium Dioxide Photocatalysts: A Dual-Pathway Study.

Phthalocyanine-sensitized TiO2 significantly enhances photocatalytic performance, but the method of phthalocyanine immobilization also plays a crucial role in its performance. In order to investigate the effect of the binding strategy of phthalocyanine and TiO2 on photocatalytic performance, a dual-pathway study has been conducted. On the one hand, zinc-tetra (N-carbonylacrylic) aminephthalocyanine (Pc) was directly grafted onto the surface of Fe3O4@SiO2@TiO2 (FST). On the other hand, Pc was immobilized on a silane coupling agent ((3-aminopropyl) triethoxysilane) grafted onto the surface of the FST. Through photocatalytic experiments on the two types of composite materials synthesized, the results showed that the photocatalyst obtained by directly sensitizing Pc (FSTP) exhibited better performance on rhodamine B(RhB) removal than did the other photocatalyst using the silane coupling agent (FSTAP). Further mechanistic studies showed that directly sensitized FSTP exhibited more efficient photogenerated electron-hole pair separation, whereas FSTAP linked by a silane coupling agent created an additional transport distance that might greatly affect the photogenerated electron transport. Therefore, the dual-pathway research in this work provides new guidance for efficiently constructing phthalocyanine-sensitized TiO2 photocatalysts.

Glass fiber treated with a glycine bridged silane coupling agent reinforcing polyamide 6(PA6): effect of hydrogen bonding.

Silane coupling agents play an indispensable role in improving interfacial adhesion of composite materials, but their interaction mechanism is often unclear. This article combines experiments and theoretical calculations to reveal the importance of hydrogen bonds between silane coupling agents and the matrix polyamide 6 in improving the mechanical properties of composite materials. Firstly, glycine bridged silane (GBSilane) was synthesized and the structure was confirmed by FT-IR, 1H NMR and HRMS. Secondly, with glass fiber treated using GBSilane as a filler, the mechanical properties of glass fiber/PA6 composite materials were studied. Compared with untreated glass fiber/PA6 composites, under the optimal treatment concentration of 1.5%, the tensile strength of glass fiber/PA6 composites treated with 3-aminopropyl triethoxysilane (APTES) and GBSilane increased by 41% and 67%, respectively, and the notch impact strength increased by 55% and 96.5%, respectively. Lastly, density functional theory (DFT) calculations revealed that stronger hydrogen bonds have formed between GBSilane and PA6 than APTES, which have induced the stronger PA6-GBSilane binding energy of 58.20 kJ mol-1. By comparison, the binding energy of PA6-APTES is only 30.91 kJ mol-1. These results demonstrated that the as-synthesized GBSilane could improve the mechanical properties of PA6 composites through an enhanced hydrogen bonding mechanism.

A fiber-shaped ultrasonic transducer by designing a flexible epoxy/nano-zirconia composite as an acoustic matching layer.

Acoustic matching layers play an important role in ultrasonic transducers. However, the acoustic matching layer with both intrinsic flexibility and high acoustic impedance remains an unmet need to achieve high-performing flexible ultrasonic transducers. Herein, we present an epoxy/nano-zirconia composite with excellent flexibility and acoustic performance by the chemical coupling method. (3-Aminopropyl)triethoxysilane was used to effectively disperse nano-zirconia particles in epoxy resin, and endow the resultant composite with flexibility. After carefully adjusting the additions of nano-zirconia particles and (3-aminopropyl)triethoxysilane, the modulus of the epoxy/nano-zirconia composite was 4.5 MPa, combined with an elongation at break over 90%. The acoustic impedance of the epoxy/nano-zirconia composite (∼4.5 MRayl) exceeded that of other typical polymer counterparts. The flexible acoustic matching layer based on an epoxy/nano-zirconia composite could significantly improve the sensitivity and bandwidth of ultrasonic transducers. A fiber-shaped ultrasonic transducer with high sensitivity and wide bandwidth was fabricated, displaying promising application potential in wearable medical electronics.

Effects of Surface-Modified Hap on the Properties of Bioceramic Paste for Sla-3D Printing

Recent advancements in additive manufacturing have sparked investments in hydroxyapatite (HAP) formation for tailored preparations. The objective of this study is twofold: to achieve a stable dispersion of HAP in the monomer reaction mixture; and to optimize the characteristics of the resulting polymerization product. By modifying hydroxyapatite with cis-9-Octadecenoamide (OAA); stearic acid (SA); and (3-Aminopropyl) triethoxysilane (A1100); we found that OAA-HAP exhibits the highest wettability with water and resin; along with the most effective dispersion within the paste. Following the optimization of the solid loading of the HAP paste to 50 wt.%, we investigated the relationship between printing process parameters and curing depth across pastes containing modified hydroxyapatite. Finally; the printed hemispherical shells; both with and without φ600 μm holes; demonstrated the efficacy of our printing approach

Enhanced upconversion luminescence of UCNPs@CsPbI3 nanocomposites via constructing multiple energy transfer channels.

The application of upconversion nanomaterials relies heavily on the ability to produce bright upconversion luminescence (UCL) or high upconversion quantum yields (UCQYs) at low power density excitation. Herein, we synthesized silica-coated NaYF4:Yb3+@NaGdF4:Tm3+@NaYF4:Tb3+ upconversion nanoparticles (UCNPs) and CsPbI3 perovskites quantum dots (PeQDs) nanocomposites by the slow hydrolysis of (3-aminopropyl)triethoxysilane. The energy transfer (ET) of Gd3+→Tb3+ accelerates the five-photon upconversion process of Yb3+-Tm3+ and the design of the core@shell@shell layer effectively mitigates the energy jumps between Gd3+ ions. Importantly, the involvement of multiple ET channels in the UCNPs@CsPbI3 PeQDs nanocomposites increased the intensity of the UCL on the CsPbI3 PeQDs by about six times. In addition, the stability of PeQDs encapsulated in a silica matrix under air and water conditions was greatly improved.

Development of a Functionalized SiO2 Supported Ni Nanoparticles Based Non-Enzymatic Amperometric Dopamine Sensor

In the present work, a novel electrochemical dopamine (DA) sensor depending on Nickel (Ni) nanoparticles deposited on (3-aminopropyl)triethoxysilane (APTES) functionalized silica (SiO2) was fabricated. For this, Ni@SiO2-APTES was synthesized by the conventional wet-impregnation method. The structure of the compozite was evaluated using Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy-energy dispersive X-ray (SEM-EDX), and X-ray diffraction (XRD). The synthesized Ni@SiO2-APTES was drop-casted on glassy carbon electrode (GCE). Also, Nafion (Nf) was drop-casted on Ni@SiO2-APTES/GCE to stabilize the electrode. The fabricated Nf/Ni@SiO2-APTES/GCE electrochemical sensor was electrochemicaly characterized using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and amperometry. CV and EIS results indicated that Ni nanoparticles increased both the conductivity and sensitivity of the working electrode. The linear detection range for DA was found to be 0.2 – 252 µM with limit of detection (LOD) was 0.07 µM depending on signal to noise ratio of 3. The sensitivity was found to be 578.26 µA mM-1 cm-2 depending on the active surface area of the modified working electrode. The sensor exhibited excellent selectivity in the presence of ascorbic acid, glucose, fructose, sucrose, mannose, uric acid, and phenylalanine. The sensor had satisfactory repeatability and reproduciblity. It was observed that the sensor showed an electrocatalytic response of 95.33% after 28 days. According to this result, it was concluded that the sensor was extremely stable within the studied time period. The applicability of Nf/Ni@SiO2-APTES/GCE was tested using dopamine HCl injection (200 mg/5 mL).

The rGO@AuNPs modified label-free electrochemical immunosensor to sensitive detection of CP-BNYVV protein of Rhizomania disease agent in sugar beet

For the first time, a novel simple label-free electrochemical immunosensor was fabricated for sensitive detection of the coat protein of beet necrotic yellow vein virus (CP-BNYVV) as the causal agent of Rhizomania disease in sugar beet. To boost the amplification of the electrochemical signal, gold nanoparticles-reduced graphene oxide (AuNPs-rGO) nanocomposite was employed to modify the glassy carbon electrode. Anti-BNYVV polyclonal was immobilized onto a modified electrode by applying a thiol linker via a self-assembly monolayer (SAM) and activating the functionalized surface using (3-aminopropyl triethoxysilane) and glutaraldehyde. The determination step relied on the forming of an immunocomplex between the antigen and oriented antibody, resulting in a decrease in current in the [Fe (CN)6]3−/4− redox reaction. The response value exhibited direct proportionality to the concentrations of CP-BNYVV. Scanning electron microscopy, energy dispersive x-ray, cyclic voltammetry, and electrochemical impedance spectroscopy techniques collectively provided a comprehensive understanding of the structural, morphological, and electrochemical features during the modification steps. Under optimized experimental conditions, the fast Fourier transform square wave voltammetry responds to the logarithm of CP-BNYVV concentrations in a wide linear range from 0.5 to 50000 pg/mL and the limit of detection is calculated to be 150 fg/mL, implying the admirable sensitivity. Selectivity assay exhibited no cross-reactivity with other proteins from interfering virus samples. Satisfactory reproducibility and stability were achieved with a relative standard deviation of 3.1% and a stable value of 90% after 25 days, respectively. More importantly, the high performance of the immunosensor resulted in the direct detection of CP-BNYVV in spiked and infected plant samples, which affords a sensing platform with huge potential application for the early detection of BNYVV virus in field conditions.Graphical

A novel anti-scaling and protection coating based on hollow periodic mesoporous organosilica encapsulated with scale inhibitor

Scaling and corrosion are common issues in the petroleum industry that compromise production safety. Currently, organic coatings are considered the most effective method for scaling inhibition. This paper presents the synthesis of hollow periodic mesoporous organosilica (HPMO) nanocontainers with a high specific surface area and a uniform, ordered mesoporous structure, using a hard template method. The morphology of HPMO was controlled by adjusting the water-to-ethanol ratio and precursor amount. Characterization of HPMO morphology and structure was conducted using scanning electron microscope, transmission electron microscope, X-ray diffraction, and nitrogen adsorption-desorption analysis. To enhance loading capacity, HPMO was modified with 3-aminopropyl triethoxysilane, increasing the encapsulation of the scale inhibitor ethylenediamine tetramethylphosphonic acid (EDTMP) from 3.6 % to 13.8 %. The modified HPMO, loaded with the scale inhibitor, significantly improved the protective and anti-scaling properties of epoxy resin coatings. Compared with pure epoxy coatings, the scale inhibition rate of the composite coating increased by 42 % under static conditions and 90 % under dynamic conditions. The crystalline morphology of calcium carbonate scale was also influenced by the scale inhibitor; EDTMP promoted the formation of acicular aragonite and inhibited cuboid calcite growth in static conditions. In dynamic conditions, aragonite was not observed, and the calcite crystals were smaller than those formed in static solutions.

Improved superhydrophobicity of magnetic melamine sponge by aminosilane for batch and continuous oil–water separation

Continuous and efficient separation remains the thorny problem that restricts oil–water separation materials for the large-scale application of oil–water separation. A kind of magnetic melamine sponges with enhanced superhydrophobicity was fabricated by dip coating of polydopamine-modified Fe3O4 nanoparticles, (3-aminopropyl)triethoxysilane (APTES) and hexadecyltrimethoxysilane (HDTMS) on melamine sponge. The superhydrophobicity of melamine sponge was improved by adding APTES to cover hydrophilic group of polydopamine. The melamine sponge exhibited water contact angle of 158.3°, the absorption capacity of 43.2–80.7 g/g, volume utilization of 0.70–0.97 v/v and separation efficiencies of 99.6 % for oil–water mixture and 98.6 % for oil/water emulsion. The sponge could carried out in batch and continuous filter devices, and repeated oil absorption capacity could achieve 92.8–96.4 % of initial oil absorption capacity after 45 absorbing-squeezing cycles. The above performances of the as-prepared sponge suggest that it is a promising candidate for large-scale application of oil-spill cleanup and oily wastewater treatment.

Preparation of a Novel Composite Coating of APP/MMT/APTES on Polyurethane with Improved Flame-Retarding Performance.

An environmentally friendly flame retardant coating for polyurethane composed of ammonium polyphosphate(APP)/montmorillonite(MMT)/(3-aminopropyl)triethoxysilane(APTES) has been prepared by deposition on a polyurethane surface through a one-step immersion, enhancing its flame retardancy. The coating of APP/MMT/APTES on the polyurethane sample surface has been verified from XPS and FTIR analysis. In comparison to untreated polyurethane, the amount of char residue after combustion of the flame-retardant polyurethane increases significantly, with a 50.8% increase in limiting oxygen index (LOI). The cone calorimetry test shows that the peak heat release rate (PHRR) and total smoke production (TSP) decreased by 80.28% and 66.7%, respectively. The formation of a dense carbon layer on the polyurethane surface restricts heat feedback from the combustion zone and reduces emission of volatiles. The preparation of polyurethane flame retardant coatings is carried out in an aqueous solution; the process is environmentally friendly and an attractive technology for polymer flame retarding.

Fabrication of novel halogen-free flame retardant containing functionalized chitosan from fisheries waste through the sol-gel technology and its fire safety performance in polyurethane resin

Chitosan (CS) derived from fisheries waste, such as shrimp and crab shells, was used to fabricate a bio-based, ecofriendly flame retardant. By reacting the –NH2 groups of CS and the NH2 groups of melamine polyphosphate (MPP) with the NCO groups of polymethylene polyphenyl polyisocyanate (PMPI), a novel intumescent flame retardant, CS-PMPI-MPP, was synthesized. Isophorone diisocyanate (IPDI) was reacted with polyol and aminopropyltriethoxysilane (APTS) to form a polyurethane containing silicon (Si-PU), into which the flame retardant was incorporated to produce a high-polymer composite through the sol-gel technology. The structure, thermal properties, flame retardancy, mechanical properties, toxicity, and char formation of the composites were analyzed. Fourier transform infrared spectroscopy, thermogravimetric analysis, limiting oxygen index, cone calorimeter, UL-94, thermogravimetric analysis with infrared spectroscopy, universal testing machine, scanning electron microscopy, X-ray photoelectron spectroscopy, raman spectroscopy, and smoke density test analyses were performed. The thermogravimetric test results indicated an increase in char yield from 0.5 wt% in pristine polyurethane to 25.9 wt% upon the addition of CS-PMPI-MPP, signifying an enhancement in the thermal stability of pristine polyurethane. According to limiting oxygen index and UL-94 data, the incorporation of CS-PMPI-MPP improved the limiting oxygen index and UL-94 ratings from 18.2 % (Fail) to 26.5 % (V-1), demonstrating the exceptional flame-retardant property of CS-PMPI-MPP within the pristine polyurethane formulation.

Controllable Synthesis of Amino-Functionalized Silica Particles via Co-condensation of Tetraethoxysilane and (3-Aminopropyl)triethoxysilane.

Amino-functionalized silica has attracted a great deal of interest due to its high surface reactivity and potential for diverse applications across various fields. While the classical co-condensation method is commonly used to synthesize amino-functionalized silica particles, the mechanism of the reaction between (3-aminopropyl)triethoxysilane (APTES) and tetraethoxysilane under different conditions remains unclear, leading to unexpected self-nucleation or cross-linking between silica particles and consequently hindering rational control over the extent of functionalization. To address this issue, we systematically explored the co-condensation growth mechanism of amino-functionalized silica particles in the Stöber method by investigating the effects of APTES concentration and water content on the hydrolysis and condensation of silanes. The experimental results revealed that APTES could decrease the rate of hydrolysis/condensation, while the moderate water content promoted both the rate of hydrolysis/condensation and the overall quality of the silica particles. Consequently, we successfully demonstrated the rational synthesis of amino-functionalized silica particles with diameters ranging from 213 to 670 nm and a nitrogen content of ≤2.8 wt %. The relationship between the APTES concentration and particle properties exhibited a biphasic trend. At low APTES concentrations (≤2.0 mM), the particle size remained stable while the isoelectric point increased rapidly. Further increasing the APTES concentration from 2.0 to 100.0 mM induced a decrease in particle size due to APTES's inhibitory effect on silica growth, with nitrogen content continuing to increase even after the isoelectric point remained unchanged. These silica particles, featuring varying surface amino group densities, were utilized as matrices for loading Au nanoparticles. The resulting functionalized particles exhibited distinctive catalytic ability in the reduction of 4-nitroaniline, demonstrating significant potential for applications across various fields.

Antitumoral action of carvedilol–a repositioning study of the drug incorporated into mesoporous silica MCM-41

We have studied repositioning of carvedilol (an antihypertensive drug) incorporated into MCM-41 mesoporous silica. The repositioning proposes a reduction in the slow pace of discovery of new drugs, as well as toxicological safety and a significant reduction in high research costs, making it an attractive strategy for researchers and large pharmaceutical companies. We obtained MCM-41 bytemplatesynthesis and functionalized it by post-synthesis grafting with aminopropyltriethoxysilane (APTES) only or with folic acid (FA), which gave MCM-41-APTES and MCM-41-APTES-FA, respectively. We characterized the materials by scanning and transmission electron microscopy, zeta potential (ZP) measurements, Fourier transform infrared absorption spectroscopy, x-ray diffractometry, nitrogen gas adsorption, and CHNS elemental analysis. We quantified the percentage of drug that was incorporated into the MCM-41 materials by thermogravimetric analysis and evaluated their cytotoxic activity in non-tumor human lung fibroblasts and the tumor human melanoma and human cervical adenocarcinoma cell lines by XTT salt reduction (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-arboxanilide). The x-ray diffractograms of the MCM-41 materials displayed low-angle peaks in the 2θrange between 2° and 3°, and the materials presented type IV nitrogen adsorption isotherms and H2 hysteresis typical of the MCM-41hexagonal network. The infrared spectra, the charge changes revealed by ZP measurements, and the CHN ratios obtained from elemental analysis showed that MCM-41 was amino-functionalized, and that carvedilol was incorporated into it. MCM-41-APTES incorporated 23.80% carvedilol, whereas MCM-41 and MCM-41-APTES-FA incorporated 18.69% and 12.71% carvedilol, respectively. Incorporated carvedilol was less cytotoxic to tumor and non-tumor cells than the pure drug. Carvedilol repositioning proved favorable and encourages further studies aimed at reducing its cytotoxicity to non-tumor cells. Such studies may allow for larger carvedilol incorporation into drug carriers or motivate the search for a new drug nanocarrier to optimize the carvedilol antitumoral activity.

Enhanced and rapid remediation of chlorpyrifos from aqueous phase by amine modified mesoporous silica SBA-15: A systematic investigation on sorption kinetics and mechanistic studies

Pesticides have become a necessary remedy of contemporary agricultural methods. However, the release of excess pesticides to the water bodies is a growing concern worldwide. Chlorpyrifos (CP), an organophosphate based pesticide used for nearly 50,000 tonnes per year globally, has significantly affected the ecosystem. Herein, we have reported that (3-Aminopropyl)triethoxysilane functionalized SBA-15 (ASBA-15) as an efficient adsorbent to remove CP from its aqueous solution to an extent of 1814 mg g−1 within 20 min. The uptake behavior was studied in detail as a function of adsorbent dosage, contact time, and concentration levels of CP. The adsorption findings were well-fitted into the Langmuir isotherm model and pseudo-second-order kinetics. The estimated values of ΔH0 and ΔS0 revealed the exothermic and spontaneous nature of the process. The XRD reflections between 2 θ = 0.90–1.8o, surface area in the ranges of 781–435 m2 g−1 and pore diameters between 7.2 and 6.0nm indicated the mesoporous as well as stable structure for SBA-15 and ASBA-15 materials at different stages of studies. FT IR studies evidenced the presence of the ‒NH group at 1541 cm−1 in ASBA-15. Thermogravimetric analysis results supported the grafting of the ‒NH group onto ASBA-15 as well as the efficient adsorption of CP. The appearance of characteristic vibration of CP at 1513 cm−1 in CP@ASBA supported the entrapment of CP within ASBA-15. The adsorption and desorption of CP by ASBA-15 were accomplished for five cycles without significant mass loss, which demonstrated the reusability, stability and reversible nature of the material.

In Situ Preparation of MnO2 on the Catechol/Silane-Coated Polypropylene Nonwoven Fabrics for Effective Removal of Cationic Dyes.

Previous studies have confirmed that MnOx removes heavy metal ions and organic pollutants from water with dual effects of adsorption and oxidation coupling, significantly improving the ability to remove impurities. Nanometal oxides have a highly reactive surface but tend to agglomerate during preparation and are challenging to recycle after use. A common method is to combine nano-MnO2 with Fe3O4 to prepare magnetic materials for easy recycling. Our previous research has confirmed that catechol (CA) and (3-aminopropyl) triethoxysilane (KH550) can be co-deposited on the surface of polypropylene nonwovens to form a stable CK coating under alkaline conditions. In addition, the coating has many active groups, including hydroxyl groups, amino groups, etc. This study further investigates the secondary reactivity of CK coatings. The coordination of catechol groups and metal ions was used to anchor manganese ions to the coating. Meanwhile, the hydroxyl and amino groups were used to reduce manganese ions to Mn4+ in situ to prepare PP-(CK-MnO2). We found that the sample had an excellent decolorization effect on cationic dyes but was limited to anionic dyes. The decolorization mechanism of cationic dyes was further discussed. The results showed that the decolorization of cationic dyes had a dual effect of adsorption and oxidative degradation. Under acidic conditions, its oxidation properties were enhanced. It can be used as a highly effective decolorizing agent for cationic dyes, and the decolorization behavior is consistent with the first-order kinetics. As the pH increases, its oxidation properties gradually decrease. Although the electrostatic adsorption effect was enhanced, the overall decolorization performance was significantly reduced. Recycling experiments have proved that it can maintain >90% removal rate after five cycles. This study also demonstrated that the CK coating has dopamine-like properties, which can coordinate with metal ions to prepare metal-organic hybrid materials.