Agent 3-aminopropyltriethoxysilane Research Articles

Preparation and characterization of crystalline poly(L‐lactic acid)/silica nanocomposite films with high ductility and gas barrier properties

AbstractIncorporating inorganic particles is a common approach to preparing polymeric materials with desirable physical properties and processability. However, this often results in increased brittleness, necessitating methods to improve melt strength and toughness. In this study, in situ polymerization was employed to functionalize silica nanoparticles with the silane coupling agent (3‐aminopropyl) triethoxysilane (APTES) as a core. A flexible chain segment, poly(butylene itaconate) (PBI), was then introduced as a “rubbery” intermediate layer, resulting in a core‐shell structure of poly(L‐lactic‐co‐butanediol itaconate) nano‐silica copolymer films (PLBISiO2) with both branched and “rubbery” structures. Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) confirmed the formation of macromolecular chains, with the molecular weight (Mn) of PLBI increasing from 59,638 to 74,306 g/mol. This significant increase supports the “rubbery” core‐shell structure. When 0.5% SiO2 was added, the T5% of the film increased by 40°C, significantly improving thermal stability. Additionally, the elongation at break increased to 265.7%, while retaining the original tensile strength. Dynamic rheology experiments further confirmed the generation of branched or “rubbery” core‐shell structures, and a doubling of gas barrier properties was observed with increased silica nanoparticles, suggesting potential applications in food packaging or biopharmaceuticals.Highlights Nanocomposites with core‐shell structure and improved mechanical properties. Dynamic rheology experiments confirmed the formation of the core‐shell structure. Significantly improved gas barrier properties due to core‐shell structure.

Antibacterial finishing of compression fabrics based on Ti3C2Tx-APTES material

Patients with hyperplastic scarring need to wear compression garments for long periods of time during treatment with compression therapy. Compression garment fabrics (CGFs) are prone to bacterial growth during use, leading to patient infections. It is essential to apply antibacterial functional finishing to the CGFs. In this study, antibacterial CGFs based on Ti3C2Tx and amino-functionalized silane coupling agent (3-aminopropyl) triethoxysilane composite material (APTES) were prepared by dip-coating method. The binding mechanism between the Ti3C2Tx-APTES and the CGF was explored, and the antibacterial rate, wash fastness, and wearability of the antibacterial fabric were investigated. The addition of APTES resulted in the formation of covalent bonds between the CGF and the antibacterial agent. The unwashed CGF exhibited antibacterial rates of 99.9% against Staphylococcus aureus (S. aureus, AATCC 25922) and 99.76% against Escherichia coli (E. coli, AATCC 6538), respectively. The wash fastness of antibacterial CGF met industry standard AA level, and the wearability of the treated fabric could basically satisfy daily wear requirements. The Ti3C2TX-APTES antimicrobial CGF prepared in this study provides an effective solution for the development of antimicrobial fabrics for sports and medical applications.

3-aminopropyltriethoxysilane modified MXene on three-dimensional nonwoven fiber substrates for low-cost, stable, and efficient solar-driven interfacial evaporation desalination

Recently, the solar-driven interfacial evaporation desalination has attracted more and more attentions due to the advantages of low cost, zero energy consumption, and high water purification rate, etc. One of the bottlenecks of this emerging technique lies in a lack of simple and low-cost ways to construct three-dimensional (3D) hierarchical microstructures for photothermal membranes. To this end, a two-step strategy is carried out by combining surface functionalization with substrate engineering. Firstly, a silane coupling agent 3-aminopropyltriethoxysilane (APTES) is grafted onto an ideal photothermal material of Ti3C2Tx MXene, to improve the nanochannel sizes and hydrophilicity, which are attributed to enlarged interspaces of MXene and introduced hydrophilic group e.g., –NH2 and –OH, respectively. Secondly, a low-cost and robust nonwoven fiber (NWF) substrate, which has a 3D micron-sized mesh structure with interlaced fiber stacks, is employed as the skeleton to load enough APTES-grafted MXene by a simple soaking method. Benefited from above design, the Ti3C2Tx-APTES/NWF composite membrane with a 3D hierarchical structure shows enhanced light scattering and utilization, water transport and vapor escape. A remarkable evaporation rate of 1.457 kg m−2 h−1 and an evaporation efficiency of 91.48 % are attained for a large-area (5 × 5 cm2) evaporator, and the evaporation rate is further increased to 1.672 kg m−2 h−1 for a small-area (2 × 2 cm2) device. The rejection rates of salt ions and heavy metal ions are higher than 99 % and 99.99 %, respectively, and the removal rates of organic dye molecules are nearly to 100 %. Besides, the composite photothermal membrane exhibits great stabilities in harsh conditions such as high salinities, long cycling, large light intensities, strong acid/alkali environments, and mechanical bending. Most importantly, the photothermal membrane shows a considerable cost-effectiveness of 89.4 g h−1/$. Hence, this study might promote the commercialization of solar-driven interfacial evaporation desalination by collaboratively considering surface modification and substrate engineering for MXene.

Functionalized boron nitride nanosheets and their polypropylene nanocomposites: influence on thermal, mechanical, rheological and wear behaviour

ABSTRACT The few-layer hexagonal boron nitride (hBN) nanosheets with hydroxyl (−OH) functional group at edges are synthesized using heat treatment of micron size hBN powder followed by sonication. These nanosheets are modified with a silane coupling agent, 3-Aminopropyl,triethoxysilane (APTES). The synthesized hBN nanosheets are mixed with the PP matrix using twin-screw extrusion followed by injection moulding. In case of APTES-modified hBN nanosheets incorporation in the PP matrix with PP-grafted maleic anhydride (PP-g-MA) shows the formation of an imide bond between the MA functional group of PP-g-MA and the amine group of APTES modified hBN nanosheets revealing compatibilization. The flow behaviour index values are lower for hBN nanosheets filled PP nanocomposites showing the improved processability from Rheological characterization. The few-layered – OH and APTES modified hBN nanosheet incorporation in the PP matrix improves the tensile and thermal properties. The incorporation of APTES modified hBN nanosheet in the PP matrix shows an increase in tensile modulus (18.1%) and tensile strength (8.1%) respectively. Wear studies show the incorporation of – OH and APTES modified hBN nanosheets in the PP matrix decreases the coefficient of friction and wear rate significantly. The wear rate at 4 min of wear testing for modified hBN nanosheet in the PP nanocomposites is ~ 96% less in comparison with neat PP. The wear mechanism is established from wear measurements and scanning electron microscopy (SEM) of worn-out wear surfaces of PP nanocomposites.

In-vitro bioactivity investigation and surface properties of a PMMA-SiO2 composite coating on SS-316L using the Sol-Gel technique

Surface modification of SS-316L using an organic and inorganic hybrid coating of polymethyl methacrylate (PMMA) and silicon dioxide (SiO2) is being conducted in the current investigation with crosslinking agent 3-aminopropyl tri-ethoxy silane (APTES). The solvent-gel method and dip coating with varying amount of SiO2 (i.e. 0.5, 1, and 1.5 wt.%) is used for surface modification. On the coated surface, Fourier transform infrared spectroscopy (FTIR) at 1000–1250 cm−1 reveals the crosslinking of silicon and PMMA. The coatings formed on SS-316L are homogenous, transparent, and free of defects and voids when seen macroscopically. A good crystallinity and presence of coated material can be seen from the X-ray diffraction and microstructure analysis of coated surface. The PMMA coating with 1.5 wt.% SiO2 has the most apatite crystals deposited on surface as observed with 7 days of immersion on simulated body fluid (SBF). These findings provide a solid link that coating SS-316L with SiO2 promotes bone bioactivity, and the PMMA+1.5 wt.% SiO2 coating can be employed on implants. The results of this study suggest a sustainable coating solution for improved bioactivity in medical applications and surgical instruments.

Effect of filler surface treatment on the physico-mechanical properties of filler/styrene-butadiene rubber nanocomposites

In the present work, the effects of various filler types and content on the characteristics and properties of styrene-butadiene rubber (SBR) were studied. This study prepared SBR filled with different fillers: kaolin, metakaolinite, synthetic zeolite Na-A, alumina (Al2O3) nanoparticles, and hybrid filler (synthetic zeolite Na-A/Al2O3). The silane coupling agent 3-aminopropyltriethoxysilane (APTES) was employed to treat the surface with fillers. Scanning electron microscope (SEM) and X-ray diffraction (XRD) were used to determine the surface morphology. The results demonstrated that fillers improved the physicomechanical properties. Tensile strength and elongation at break (%) in composites containing synthetic zeolite Na-A increased by up to 158.6% at 3 phr and 100% at 2 phr, respectively. The results showed that the surface properties displayed by SEM analysis indicated a good distribution of filler particles. Also, the rubber compound’s resistance to organic solvents such as toluene was improved, as evidenced by swelling properties; the swelling ratio decreased by 17.5% while the crosslink density increased by 42.6% at 5 phr Al2O3/synthetic zeolite Na-A. The constants of the various hyperelastic models that explain the behavior of the composite materials under study were determined, and their predictions of the experimentally obtained stress-strain curves were compared. The study’s experimental findings will be helpful for several industrial uses, including an extender in water-based paints, rubber fillers, ceramic materials, paper fillers, and coating pigments.

P/N/Si-rich and flexible coating imparting polypropylene excellent flame retardancy without compromising its inherent mechanical properties

In general, the addition of flame retardants may lead to the degradation of the mechanical properties of polymers, despite enhancing their flame retardancy. However, flame-retardant coatings have the potential to provide good flame resistance to polymers without compromising their inherent mechanical properties. In this study, we applied highly adhesive and flexible polysiloxane flame-retardant coatings (196 μm) to polypropylene, resulting in reductions of 74.9 %, 58.0 %, 80.0 %, and 56.4 % in peak heat release rate, peak smoke production rate, fire growth rate, and mass loss, respectively. By incorporating the lab-synthesized DOPO-modified polysiloxane (APID), the flame-retardant efficiency of ammonium polyphosphate (APP) was greatly enhanced. The primary film-forming agent, (3-aminopropyl) triethoxysilane (APTES), played a key role in maintaining the compatibility of APP and APID with the coating, as well as facilitating the formation of a robust SiOSi crosslinked network structure that strengthened the resulting char layer. The interactivity between the various components, including hydrogen bonds and crosslinked network structures, contributed to improved uniformity, thermal stability, and adhesion of the coatings. Moreover, the coatings exhibited resistance to ultraviolet radiation and water. Our findings suggest that highly flexible and adhesive flame-retardant coatings hold significant potential for applications in polymer protection. These promising results provide a viable pathway for improving the fire protection of polymers through the use of high-adhesive intumescent flame-retardant coatings.

APTES-mediated Cu2(OH)3(NO3) Nanomaterials on the Surface of Silicone Catheters for Abscess

Metal-based nanomaterials have remarkable bactericidal effects; however, their toxicity cannot be disregarded. To address this concern, we developed a simple synthesis route for antibacterial catheters using metal-based nanomaterials to reduce toxicity while harnessing their excellent bactericidal properties. The grafting agent (3-aminopropyl)triethoxysilane (APTES) forms -NH2 groups on the catheter surface, onto which copper ions form a nanomaterial complex known as Cu2(OH)3(NO3) (defined as SA-Cu). The synthesized SA-Cu exhibited outstanding contact antibacterial effects, as observed through scanning electron microscopy (SEM), which revealed cell membrane crumbing and bacterial rupture on the catheter surface. Furthermore, SA-Cu exhibited excellent biosafety characteristics, as evidenced by the cell counting kit-8 (CCK-8) assay, which showed no significant cytotoxicity. SA-Cu demonstrated sustained antimicrobial capacity, with in vivo experiments demonstrating over 99% bactericidal efficacy against methicillin-resistant Staphylococcus aureus (MRSA) for two weeks. The transcriptome sequencing results suggested that SA-Cu may exert its bactericidal effects by interfering with histidine and purine metabolism in MRSA. This study presents a straightforward method for synthesizing antimicrobial silicone catheters containing copper nanomaterials using copper ions.

Large-area grown ultrathin molybdenum oxides for label-free sensitive biomarker detection.

The rise of two-dimensional (2D) materials has provided a confined geometry and yielded methods for guiding electrons at the nanoscale level. 2D material-enabled electronic devices can interact and transduce the subtle charge perturbation and permit significant advancement in molecule discrimination technology with high accuracy, sensitivity, and specificity, leaving a significant impact on disease diagnosis and health monitoring. However, high-performance biosensors with scalable fabrication ability and simple protocols have yet to be fully realized due to the challenges in wafer-scale 2D film synthesis and integration with electronics. Here, we propose a molybdenum oxide (MoOx)-interdigitated electrode (IDE)-based label-free biosensing chip, which stands out for its wafer-scale dimension, tunability, ease of integration and compatibility with the complementary metal-oxide-semiconductor (CMOS) fabrication. The device surface is biofunctionalized with monoclonal anti-carcinoembryonic antigen antibodies (anti-CEA) via the linkage agent (3-aminopropyl)triethoxysilane (APTES) for carcinoembryonic antigen (CEA) detection and is characterized step-by-step to reveal the working mechanism. A wide range and real-time response of the CEA concentration from 0.1 to 100 ng mL-1 and a low limit of detection (LOD) of 0.015 ng mL-1 were achieved, meeting the clinical requirements for cancer diagnosis and prognosis in serum. The MoOx-IDE biosensor also demonstrates strong surface affinity towards molecules and high selectivity using L-cysteine (L-Cys), glycine (Gly), glucose (Glu), bovine serum albumin (BSA), and immunoglobulin G (IgG). This study showcases a simple, scalable, and low-cost strategy to create a nanoelectronic biosensing platform to achieve high-performance cancer biomarker discrimination capabilities.

Preparation and Properties of Phenolic Epoxy Modified Silicone Resin

Phenolic epoxy resin (F51) was first reacted with silane coupling agent (3-aminopropyl)triethoxysilane (KH550) to form a silanized phenolic epoxy resin (SPER); then the SPER was copolymerized with methylphenyl silicone resin (MPS) to synthesize phenolic epoxy modified silicone copolymer (PEMSC). The chemical structure of the PEMSC was characterized by FT-IR. The results of tensile strength and shear strength measurements indicated that the successful introduction of F51 significantly improved the mechanical and adhesive properties of the PEMSC; compared with the PEMSC with 10 phr of F51 added, the tensile strength and shear strength of the PEMSC with 40 phr increased by 8.5 and 3.5 times respectively. The TGA and DTGA analysis showed that the initial thermal decomposition temperature and the residual weight of PEMSC at 800 °C decreased compared to MPS, but the temperature corresponding to the maximum thermal decomposition rate in the second stage increased. Qualitative analysis was conducted on the decomposition products of PEMSC using gas chromatography coupled with mass spectrometry (GC-MS). The results showed that the relative content of aromatic hydrocarbons and their derivatives in the decomposition products of PEMSC was 64.11%, and the relative content of cyclic trimers and higher cyclomers was 20.41%.

A study of high-strength and durable cotton fabric joining via laser-induced polymerisation of silica-sol photosensitive resin

Cotton is the most popular fabric used in human clothing and garment, and its joining process is still based on the traditional sewing method. In this study, a new approach to cotton fabric joining via UV-laser induced polymerisation was investigated, which involved preparation of a silane coupling agent (3-Aminopropyl) triethoxysilane (3-Aps) for surface modification of cotton fabric, and formulation and application of a silica-sol photosensitive resin as the filler. The developed resin consists of two other silanes, Silane A174 and KH560 so as to provide chemical bonds with the cellulose of cotton surface and the 3-Aps modified cotton. The results showed that the silica-sol resin not only produced self-polymerisation due to photothermal effect, but also joined with the fiber surfaces by chemical bonding, which enhanced the surface interaction with cotton fibers and obtained excellent mechanical properties. The heat accumulation at joint was detected in real-time using the infrared thermography, which ensured the fast drying and curing of the silica-sol containing resin. With 4 % silica-sol content in resin, the interfacial bonding was optimal for APS-Fabric, and the tensile force of the 2 mm joint reached 300 N exceeding the ultimate breaking strength of the cotton fabric itself. The fabric joint was demonstrated to withstand at least 20 washing cycles without cracking. This new fabric joining technique provides both strong bonding and sufficient flexibility in the joints, resulting in high strength and durable cotton fabric joining, which has a broad application prospect in the field of apparel.

Surface modification of lithium-ion sieves by silane coupling agent for improved adsorption performance

Solid-phase reaction is a promising method to synthesize lithium-ion sieves H2TiO3 (HTO) for simple production process. However, the uneven mixing of raw materials during the solid-phase reaction causes the agglomeration phenomenon. In this work, silane coupling agent (3-aminopropyl)triethoxysilane (KH550) was employed for surface modification of HTO to yield the HTO/KH550 composite by forming covalent bond. The crystallinity, composition, morphology, and porosity of HTO/KH550 were characterized by a series of techniques. The agglomeration phenomenon was well alleviated and HTO/KH550 showed increased surface area. The adsorption experiments were detailed carried out by varying the different factors. HTO/KH550 exhibited improved lithium adsorption capacity and adsorption rate constant (25.61 mg·g−1 and 0.0037 mg·g−1·h−1 vs 22.41 mg·g−1 and 0.0020 mg·g−1·h−1 of HTO) derived from surface modification by KH550. Ion exchange mechanism in the adsorption process was revealed by X-ray photoelectron spectroscopy (XPS). Selective adsorption experiments were performed and HTO/KH550 exhibited the partition coefficient (Kd) of Li+ much higher than the competing ions (Na+, Mg2+, K+, and Ca2+). Furthermore, HTO/KH550 showed excellent cyclic stability with the adsorption capacity loss of only 3.3 % after five adsorption–desorption cycles. This work is of guiding significance to synthesize surface modified lithium-ion sieves for industrial production.

High-performance, renewable thermal insulators based on silylated date palm fiber–reinforced poly(β-hydroxybutyrate) composites

Developing insulating materials with minimal environmental impacts and enhanced properties has been the primary challenge in recent years. To address these challenges, date palm fiber (DPF) was treated with a silane coupling agent 3-aminopropyl triethoxysilane and two grafting solvents (acetone and ethanol) via the wet chemical method. The treated fibers were used to prepare poly(β-hydroxybutyrate) (PHB)-based composites via melt blending, thermo-compression molding, and annealing. The insulation properties of these green composites revealed that the silylated fiber composites possess an appropriate thermal conductivity, of 0.0901–0.106 W/(m·K). In cold and hot water, the silylated fiber composites drastically decreased water absorption by 20% and 34%, respectively. The tensile strength of the silylated fiber composites reached 18 MPa owing to improved compatibility, and the highest compressive strength was 48.6 MPa with a filler content of 40 wt%. The heat of combustion for silylated fiber composites ranged from 20.79 to 21.94 MJ/kg. The results indicate that silylated DPF-based PHB composites have potential for use in building engineering.

Construction of silane-modified nanoscale magnesium hydroxide as an inorganic flame-retardant coating for silk textiles

Inorganic magnesium hydroxide nanoparticles (Mg(OH)2 NPs) offer a promising halogen-/phosphorus-free flame-retardant solution for silk. However, achieving effective and durable flame retardancy remains a challenge. In this study, silane-modified Mg(OH)2 NPs were prepared using the double drop-reverse precipitation method with the silane coupling agent 3-aminopropyltriethoxysilane as a surface modifier. The chemical bonding between silane-modified Mg(OH)2 NPs and silk fabric was beneficial for improving the stabilization and durability of the functional particles on the silk surface. The surface morphology and structure of the silane-modified Mg(OH)2 NPs, as well as the smoke and heat generation performance, flame retardancy, washing durability, and flame-retardant mechanism of the coated silk fabrics were investigated. The coated silk fabric exhibited high flame-retardant efficiency and significantly reduced smoke and heat generation, indicating a lower fire hazard. Additionally, the coated silk fabric displayed self-extinguishing behavior even after 15 robust washings, demonstrating high washing durability. The coated silk exhibited fibrous and weave structures after combustion, indicating a strong charring ability. Overall, this study presents a promising approach for the development of flame-retardant silk fabrics with excellent washing durability using inorganic Mg(OH)2 NPs.

Modified SiO2 microspheres/polyacrylate resin composites for the enhancement of oil-absorbing performance

Inserting inorganic materials into the skeleton of oil-absorbing resin (OAR) would weaken the interchain winding of polymer, regulate the pore channel structure, and thus enhance the oil-absorbing performance. However, the effects of surface modifiers on the oil-absorbing ability have been rarely explored. Herein, SiO2 microspheres coated with three kinds of silane coupling agents (3-aminopropyltriethoxysilane (APTES), γ-(methacryloxypropyl) trimethoxy silane (MEMO) and chlorotrimethylsilane (TMCS)) were composited with P(SMA-co-BA-co-ST) (octadecyl methacrylate (SMA), butyl acrylate (BA) and styrene (ST)). The as-prepared composite resin microspheres (OAR-APTES-SiO2, OAR-MEMO-SiO2 and OAR-TMCS-SiO2) were fully characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), optical microscopy (OM) and thermal gravimetric analysis (TGA). The results showed that the average particle sizes of the as-prepared SiO2 microspheres were nearly 300 nm and the silane coupling agent of APTES exhibited the best surface modification for SiO2 microspheres (grafting rate reached 16.78%). While, the average particle sizes of composite resins (OAR-APTES-SiO2, OAR-MEMO-SiO2 and OAR-TMCS-SiO2) were nearly 1.5 mm, 2 mm and 2.5 mm, respectively. Meanwhile, composite resin OAR-APTES-SiO2 showed the highest saturated oil-absorbing capacities, which were calculated to be 44.97, 38.12, 27.29 and 22.86 g/g for CCl4, CHCl3, CH2Cl2 and gasoline, respectively, under the optimal adding amount of SiO2 (ω(SiO2) = 0.8%), reaching more than 90% of the saturated oil-absorbing capacity in 30 min. Meanwhile, the oil-absorbing capacity of composite resin is 1.34 times higher than that of bare acrylic resin. It can be recycled 7 times without the obvious decrease in oil absorption ability. This study provides a novel method for the preparation of composite materials with high stability, high oil-absorbing capacity and low-saturation oil-absorbing time by regulating the resin pore structure.

Nanostructured system based on hydroxyapatite and curcumin: A promising candidate for osteosarcoma therapy

Osteosarcoma is the most common type of bone cancer. Despite therapeutic progress, survival rates for metastatic cases or that do not respond well to chemotherapy remain in the 30% range. In this sense, the use of nanotechnology to develop targeted and more effective therapies is a promising tool in the fight against cancer. Nanostructured hydroxyapatite, due to its biocompatibility and the wide possibility of functionalization, is an interesting material to design nanoplatforms for targeted drug delivery. These platforms have the potential to enable the use of natural substances in the fight against cancer, such as curcumin. Curcumin is a polyphenol with promising properties in treating various types of cancer, including osteosarcoma. In this work, hydroxyapatite (n-HA) nanorods synthesized by the hydrothermal method were investigated as a carrier for curcumin. For this, first-principle calculations based on the Density Functional Theory (DFT) were performed, in which the modification of curcumin (CM) with the coupling agent (3-aminopropyl) triethoxysilane (APTES) was theoretically evaluated. Curcumin was incorporated in n-HA and the drug loading stability was evaluated by leaching test. Samples were characterized by a multi-techniques approach, including Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy (UV–Vis), X-ray diffraction (XRD), X-ray fluorescence spectrometry (FRX), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), zeta potential analysis (ζ), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The results show that n-HAs with a 90 nm average size were obtained and successful incorporation of curcumin in the nanostructure was achieved. Cell viability and the number of osteosarcoma cells were decreased by CMAP-HA treatment. Furthermore, the stability test suggests that hydroxyapatite nanoparticles present great potential for the transportation of curcumin in the bloodstream, crediting this system for biological performance evaluations aiming at the treatment of osteosarcomas. Keywords: nanostructures, curcumin, hydroxyapatite, osteosarcoma.

Preparation and anti-corrosion properties of 8-HQ@SiO2@AK/EP composite materials

Epoxy coatings are popular due to their strong adhesion, low cost, and superior thermal and electrical insulation. Unfortunately, surface defects in epoxy resin lead to surface cracks, limiting the long-term use of epoxy resin coatings in humid marine environments. In this study, modified kaolin (Kaolin) was added to an epoxy resin (EP) to enhance its corrosion resistance, and a silane coupling agent 3-aminopropyltriethoxysilane (APTES), tetraethyl orthosilicate (TEOS), and 8-hydroxyquinoline (8-HQ) were chosen as modifiers. This resulted in the composite 8-hydroxyquinoline/silica/amino kaolin (8-HQ@SiO2@AK), and the structural makeup, loading, hydrophobic characteristics, surface roughness, and corrosion resistance of 8-HQ@SiO2@AK and 8-hydroxyquinoline/silica/amino kaolin/epoxy resin composite coating (8-HQ@SiO2@AK/EP) was investigated. Based on these findings, the maximum contact angle of the hydrophobic composite coating was 88°, its roughness Ra was 3.09 nm, and the hardness and adhesion were unaltered compared to silica-modified kaolin/epoxy composite coatings (SiO2@AK/EP). The impedance modulus |Z|0.01 Hz of the composite was 3.662×109 Ω • cm2 after 30 days of immersion, which indicated significantly enhanced corrosion resistance.

Preparation of Copper Nanoparticles/Diatomite Nanocomposite for Improvement in Water Quality of Fishponds

Diatomite (DA) with the main component of silica (SiO2) was chemically modified by amine groups of the coupling agent 3-amino propyl triethoxysilane (APTES) before deposition of Cu2+ ions. The mixture of DA-APTES and Cu2+ ions in the chitosan stabilizer (1%) was added with ascorbic acid and purged oxygen by N2O for antioxidation before irradiation. Cu2+ ions were reduced to Cu0 and aggregation into copper nanoparticles (CuNPs) on DA by an electron beam (EB). Characterizations of CuNPs onto DA were determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES), UV-Vis spectra, transmission electron micrography (TEM), Fourier transform infrared (FT-IR) spectra, and BET-specific surface area. A nanocomposite of CuNPs/DA with the porous structure of DA is capable of improving the water quality by adsorption of organic pollutants and suspended solids. Therefore, the values of chemical oxygen demand (COD) and biochemical oxygen demand (BOD5) decreased for samples of fishpond water after treatment with CuNPs/DA. Antibacterial activity of CuNPs/DA nanocomposite against pathogenous bacteria for catfish such as Aeromonas hydrophila and Edwardsiella ictaluri was estimated.

Ni and Ce Grafted Ordered Mesoporous Silica KIT-6 for CO2 Adsorption

In this study, the Ni/KIT-6 and Ce/KIT-6 materials were prepared through the impregnation method and then amino-functionalized materials were obtained by the grafting of an amino-silane coupling agent 3-aminopropyl triethoxysilane (APTES). The samples were characterized by thermogravimetric analysis (TGA-DTA), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction, scanning electron microscopy (SEM) and nitrogen adsorption at 77 K. The study of CO2 adsorption–desorption on prepared materials was investigated using thermogravimetric analysis (TGA-DTA) coupled with mass spectrometry (MS). The influence of metal oxides on the performance of CO2 adsorption on functionalized mesoporous silica was presented. The results showed that doping the molecular sieve with cerium oxide can significantly increase the adsorption capacity of the amino-functionalized KIT-6. As the CO2 adsorbents were prepared by functionalization through grafting with APTES, the amount of amine loading is one of the important factors which improves CO2 adsorption capacity. Additionally, CO2 adsorption performance depends on the textural properties and the temperature used for the adsorption process. The maximum adsorption capacity of Ce/KIT-6 Sil is 3.66 mmol/g, which is 2.4 times higher than Ni/KIT-6 Sil. After the nine cycles of cyclic CO2 adsorption/desorption, the Ce/KIT-6 Sil still had higher adsorption capacities, indicating their good cyclical stability.

Polyamidoamine dendrimer-functionalized silica nanocomposite with polydopamine coating for dispersive micro solid-phase extraction of benzoylurea insecticides in water samples

近年来,由农药残留导致的环境污染问题已引起社会的广泛关注,开发便捷高效的分析方法对农药残留进行检测和监测十分必要。研究设计并成功制备了聚多巴胺涂敷的聚酰胺-胺树状分子功能化的二氧化硅复合材料(SiO2-PAMAM-PDA),并采用透射电镜对其进行表征。开发了以此复合材料为吸附剂的分散微固相萃取方法(D-μ-SPE),并结合高效液相色谱对水基质中的4种苯甲酰脲类杀虫剂(BUs)残留进行了富集检测。多巴胺结构中含有丰富的苯环、氨基及羟基,可与目标物形成氢键、π-π相互作用,从而增强了材料对苯甲酰脲的萃取能力。对吸附剂用量、萃取时间等可能影响萃取效率的条件进行了单因素优化。在最优条件下,该方法的线性范围在10~500 μg/L之间,根据3倍信噪比(S/N)计算所得的检出限(LOD)为1.1~2.1 μg/L,回收率为82.8%~94.1%,相对标准偏差(RSD)为2.1%~8.0%。将建立的方法与已报道的以苯甲酰脲作为目标物的方法进行了对比,发现方法样品用量及萃取剂用量均较少,且所需前处理时间较短,有机溶剂消耗也较少,为苯甲酰脲类农药的检测提供了更快速、绿色的选择。为评估所开发方法的实际样品适用性,将其应用于3种河水样品中4种苯甲酰脲类杀虫剂的分析检测,所得回收率及RSD分别为69.5%~99.4%和0.2%~9.5%,表明此方法在实际样品中同样具有较高的准确性和精密度。