查找使用阿拉丁产品的科研文献

Beetle-Exoskeleton-Inspired Fluorine-Free PDA/Chitosan–SiO2/PDMS Coating for Cotton: Durable Self-Cleaning, Self-Healing, Antibacterial Activity, and Oil–Water Separation

Rongdi Wu,Jitong Han,Weichao Chen,Xin Yu,Ruixin Gao,Chunming Zhang

A biomimetic, fluorine-free, three-layer aqueous coating for cotton─composed of an Fe2+/Cu2+-catalyzed polydopamine (PDA) primer, a chitosan–SiO2 (CS) aerogel midlayer, and a thin polydimethylsiloxane (PDMS) overcoat─was developed to impart durable superhydrophobicity, rapid photothermal self-healing, antibacterial activity, and efficient oil–water separation. Treated cotton exhibited a static water contact angle (WCA) of 170° and retained a WCA of >155° after 2500 Martindale abrasion cycles or 30 ISO 105-C06 wash cycles; the WCA was restored to ≥160° after ambient storage or within 20 min under natural sunlight as surface temperatures approached ≈50 °C. PDA-mediated Cu2+ chelation (5 mM) produced >99% inhibition of Escherichia coli and Staphylococcus aureus; gravity-driven oil–water separation efficiencies exceeded 98% with >96% retention after 12 cycles. Preliminary scalability and environmental impact analyses, including material inventories and PDMS release estimates, support the potential for industrial translation. This fluorine-free, beetle-exoskeleton-inspired strategy offers a scalable route to multifunctional, sustainable textile finishing and environmental remediation.

Two birds with one stone: insights into the micro-morphologies of SiO2 spheres for simultaneously enhancing the fire safety and radiative cooling performance

Wei Cai,Bicheng Lin,Tianyang Cui,Yang Ming,Yunhuan Liu,Ruofan Yang,Mohammad Ziaur Rahman,Weiyi Xing,Bin Fei,Deyi Wang

Even though radiative cooling materials have demonstrated significant potential in decreasing energy consumption, pursuing higher efficiency and multi-functionality still remains a huge challenge. Herein, we first design four kinds of silicon dioxides (SiO 2 ) spheres that are widely explored and employed due to high infrared emissivity, to analyze the intrinsic mechanism between micro-morphologies and reflectivity properties. Besides, applicable to real application, we further add dendritic SiO 2 spheres with highest reflectivity into polyurethane (PU) resin, thus achieving an advanced PU-based film. Based on reflectivity of 95.5% and IR emissivity of 94.5%, the PU/dendritic SiO 2 composite film achieves sub-ambient temperatures of ∼7.9 °C and ∼7.3 °C, in nighttime and daytime, respectively. Attributed to its large specific surface and dendritic structure, SiO 2 spheres effectively suppress the escape of pyrolysis products that are further captured and converted into protective layer, by increasing melting viscosity. Consequently, the time and value of peak heat release rate in composite films are postponed by 13 s and decreased by 48.4%, respectively. In conclusion, based on “Two birds with one stone” strategy, this work provides a design thought for realizing the higher cooling efficiency and multi-functionality, thus significantly decreasing energy consumption and guaranteeing high fire safety in emerging buildings.

Lightweight and strong toughness of polyimide/SiO2 composite aerogels with super-high working temperature for high-performance thermal insulation and flame-resistant application

Li Dandan,Ye Qibin,Zhao Dong,Li Hui,Chen Chunhai,Qian Guangtao,Yang Jinjun

As the continuous development of aerospace and outer space exploration, high-performance thermal insulation materials with high-temperature resistance and attractive mechanical properties have always been a fascinating topic of research to protect human body or components from extreme environments. In this research, hydrophobic silicon dioxide (SiO 2 ) nanoparticles as molecular skeleton enhancers and heat transfer inhibitors are introduced in crosslinked polyimide (PI) aerogels with rigid molecular structure to maintain the stable nanoporous network structure. The density, shrinkage, porosity, specific surface area and pore size distribution of PI/SiO 2 composite aerogels can be adjusted by the addition of SiO 2 nanoparticles, so as to improve the comprehensive performances. The excellent thermal stability and mechanical properties of PI/SiO 2 composite aerogels with super-high working temperature of over 550 °C and high modulus of compression and tension (compression Young’s modulus of 37.75 MPa and tensile modulus of 237.1 MPa) ensure their use as a structural component. The charming thermal conductivity (29.7 mWm −1  K −1 ) and excellent flame resistance make them a candidate for high-performance thermal insulation materials. Graphical abstract

Design order macro-meso porous structure monolithic Co3O4/SiO2 catalyst via a novel 3D printing for the highly efficient catalytic combustion of toluene

Yuntai Xi,Fang Dong,Zhongying Ji,Zhicheng Tang,Jiyi Zhang

The shortcomings of Co-based powder catalysts such as amorphous susceptibility to loss and high influence by pressure drop have become the key factors affecting their catalytic activity. In this paper, two methods were proposed to prepare novel monolithic Co 3 O 4 /SiO 2 catalysts by 3D direct ink writing (DIW) technology: (1) one-step method of printing the active component with supports, (2) two-step method of printing the support first, and then loading the active components. The results showed that the monolithic catalyst prepared by the two-step method possessed more abundant Co 3+ and lattice oxygen (O latt ) species than the one-step method, which jointly promoted the catalytic conversion of toluene. However, the catalyst printed by the one-step method had a stronger interaction between the active component and the support, showing better thermal stability and water resistance. In addition, the SiO 2 support (the calcined product after SiO 2 ink printing) enhances the activity, stability, compression resistance, while the N–SiO 2 support (the calcined product after SiO 2 precursor ink printing) can effectively prevent blockage of the pore structure by the binder and increase physical properties such as pore volume and specific surface area of Co 3 O 4 /SiO 2 catalyst.

An Ultrasensitive Electrochemical Immunosensor for HIV p24 Based on Fe3O4@SiO2 Nanomagnetic Probes and Nanogold Colloid-Labeled Enzyme–Antibody Copolymer as Signal Tag

Ning Gan,Xiaowen Du,Yuting Cao,Futao Hu,Tianhua Li,Qianli Jiang

An ultrasensitive portable electrochemical immunosensor for human immunodeficiency virus p24 (HIV p24) antigen detection has been developed, whereby the detection sensitivity was 1000 times higher than that of the ELISA method. Firstly, a novel HRP enzyme–antibody copolymer (EV-p24 Ab2) was synthesized through an EnVision regent (EV, a dextrin amine skeleton anchoring more than 100 molecules of HRP and 15 molecules of anti IgG), then incubated in the secondary antibody of p24. Secondly, the copolymer was immobilized on the gold nanocolloids (AuNPs) to fabricate a novel signal tag (AuNPs/EV-p24 Ab2). Subsequently, a sandwich-type immunoreaction would take place between the capture probe (silicon dioxide-coated magnetic Fe3O4nanoparticles (MNPs) labeled with the primary p24 antibody (MNPs-p24 Ab1)), p24 (different concentrations) and the signal tag [AuNPs/EV-p24 Ab2)] to form the immunocomplex. Finally, the immunocomplex was absorbed on the surface of screen printed carbon electrode (SPCE) by a magnet and immersed in the o-hydroxyl phenol (HQ) and H2O2. The large amounts of HRP on the signal tag can catalyze the oxidation of HQ by H2O2, which can induce an amplified reductive current. Moreover, the capture probe could improve the accumulation ability of p24 and facilitate its separation from the substrate through the magnet. Under optimal conditions, the proposed immunoassay exhibited good sensitivity to p24 within a certain concentration range from 0.001 to 10.00 ng/mL, with a detection limit of 0.5 pg/mL (S/N = 3). The proposed method can be used for real-time and early detection of HIV-infected people.

The preparation of a high performance near-infrared shielding CsxWO3/SiO2 composite resin coating and research on its optical stability under ultraviolet illumination

Xianzhe Zeng,Yijie Zhou,Shidong Ji,Hongjie Luo,Heliang Yao,Xiao Huang,Ping Jin

Cesium-doped tungsten bronze CsxWO3 is an ideal near infrared (NIR) shielding material for solar filters. However, the CsxWO3 nanoparticle dispersed resin film exhibits obvious photochromic behavior under ultraviolet (UV) illumination, which severely hinders the commercial application of CsxWO3. In this paper, CsxWO3/SiO2 composite resin coatings were successfully prepared with excellent NIR shielding ability and outstanding optical stability under strong UV illumination by combining an ultraviolet-absorbing agent (UVA) with SiO2. The roles of UVA and SiO2 in preventing the photochromic behavior of the CsxWO3/SiO2 composite resin coating were vital, reducing the photochromic reaction rate by UVA and limiting the photochromic reaction areas by SiO2. In sum, our research provides a new solution for eliminating the photochromism of a CsxWO3-based resin film and it may have practical application in architecture and automobiles.

Novel magnetically separable anhydride-functionalized Fe3O4@SiO2@PEI-NTDA nanoparticles as effective adsorbents: synthesis, stability and recyclable adsorption performance for heavy metal ions

Chaoyang Jia,Junhong Zhao,Liling Lei,Xiyang Kang,Ran Lu,Chongtao Chen,Shunling Li,Yale Zhao,Qingxiang Yang,Zhijun Chen

In this paper, a novel adsorbent, Fe3O4@SiO2@PEI-NTDA, was first prepared by the immobilization of an amine and anhydride onto magnetic Fe3O4@SiO2 nanoparticles with polyethylenimine (PEI) and 1,4,5,8-naphthalenetetracarboxylic-dianhydride (NTDA) for the removal of heavy metal ions from aqueous solutions. The structure of Fe3O4@SiO2@PEI-NTDA was systematically investigated; the results confirmed that amine and anhydride groups were successfully covalently grafted onto the surface of Fe3O4@SiO2, which showed a homogenous core–shell structure with three layers of about 300 nm diameter (Fe3O4 core: 200 nm, nSiO2 layer: 20 nm, and PEI-NTDA layer: 20 nm). The adsorption performance of Fe3O4@SiO2@PEI-NTDA NPs was evaluated for single Pb2+ and coexisting Cd2+, Ni2+, Cu2+, and Zn2+ ions in an aqueous solution in a batch system. The amine and anhydride groups may have a synergistic effect on Pb2+ removal through electrostatic interactions and chelation; Fe3O4@SiO2@PEI-NTDA NPs exhibited preferable removal of Pb2+ with maximum adsorption capacity of 285.3 mg g−1 for Pb2+ at a solution pH of 6.0, adsorbent dosage of 0.5 g L−1, initial Pb2+ concentration of 200 mg L−1 and contact time of 3 h. The adsorption mechanism conformed well to the Langmuir isotherm model, and the adsorption kinetic data were found to fit the pseudo-second order model. Fe3O4@SiO2@PEI-NTDA NPs could be recovered easily from their dispersion by an external magnetic field and demonstrated good recyclability and reusability for at least 6 cycles with a high adsorption capacity above 204.5 mg g−1. The magnetic adsorbents showed high stability with a weight loss below 0.65% in the acid leaching treatment by 2 M HCl solution for 144 h. This study indicates that Fe3O4@SiO2@PEI-NTDA NPs are new promising adsorbents for the effective removal of Pb2+ in wastewater treatment.

Synthesis of raspberry-like polymer/SiO2 hybrid colloidal spheres grafted by block-copolymer poly(MPC-b-MPS) for underwater superoleophobic anti-biofouling coatings

Shengyang Pan,Min Chen,Limin Wu

Raspberry-like polymer/inorganic compound hybrid colloidal spheres have attracted tremendous interest owing to their many potential applications, but most of them are concentrated on synthesis methods, controlling structures and morphologies. Herein, we synthesize raspberry-like poly(ethyl methacrylate)/SiO 2 colloidal spheres and further graft a hydrophilic diblock copolymer on the SiO 2 nanoparticles. The obtained copolymer-grafted hybrid sphere-based coatings are robust and display excellent underwater superoleophobic and anti-biofouling performances as well as self-repairing ability.

Corrosion behavior and mechanical properties of SiC/SiC composite joints with Y2O3-Al2O3-SiO2 interlayer under high-temperature steam environments at 1200 °C

Shaobo Yang,Chenxi Liang,Jiali Li,Yujie Ma,Sijie Kou,Juanli Deng,Bo Chen,Shangwu Fan

The study investigated the corrosion behavior and mechanical performance of SiC/SiC composite joints with Y 2 O 3 -Al 2 O 3 -SiO 2 (YAS) interlayers under high-temperature steam environments at 1200 °C. Under low-flow conditions, partial disruption of Si-O and Al-O bonds in the YAS glass network reduced crosslinking, forming an aluminosilicate protective layer that inhibited further corrosion. Prolonged exposure led to Y 3+ migration and accumulation, resulting in Y 2 Si 2 O 7 precipitation and growth. High-flow conditions caused a thinner glass layer, continuous longitudinal cracks, and more severe erosion and dissolution of the YAS glass due to higher steam velocity. Despite these degradations, the joints exhibited satisfactory performance, maintaining shear strengths of about 40 ± 2 MPa after 15 h of low-flow exposure and about 36 ± 5 MPa after 5 h of high-flow exposure. These findings demonstrate that YAS interlayers provide excellent corrosion resistance and mechanical stability as a sealant for nuclear-grade SiC/SiC.

Biogenic synthesis of ferrous(III) oxide and Fe3O4/SiO2 using Chlorella sp. and its adsorption properties of water contaminated with copper(II) ions

Shireen Ibrahim Hamadamin,Sewgil Saaduldeen Anwer,Parween Mohsin Abdulkareem,Kwestan Hassan Sdiq

Selective hydrodeoxygenation of p-cresol as a model for coal tar distillate on Ni–M/SiO2 (M = Ce, Co, Sn, Fe) bimetallic catalysts

Liuyi Pan,Yulong He,Menglong Niu,Yong Dan,Wenhong Li

Ni–M/SiO2 with different binary metals M (M = Ce, Co, Sn, Fe) prepared by an incipient impregnation method was used in the hydrodeoxygenation (HDO) of low-temperature coal tar distillate, which is rich in phenolic compounds. p-Cresol, as a model compound of the distillate, was used to evaluate the activity and selectivity of BTX products on the series of reduced Ni–M/SiO2 catalysts in a fixed bed reactor. The properties of the catalysts were characterized by N2 adsorption–desorption, ICP-AES, XRD, H2-TPR, and XPS. Benzene and toluene as the direct deoxygenation (DDO) products and cyclohexane and methylcyclohexane as the hydrogenolysis (HYD) products were detected to evaluate the selectivity of the path in the deoxygenation process. In this series of catalysts, the order of reactivity was Ni–Ce > Ni–Sn > Ni–Co > Ni–Fe > monometallic Ni. Meanwhile, the addition of Ce and Co loaded in the Lewis acid sites of the catalyst affected the electron distribution of nickel atom and its atomic arrangement on the surface of the carrier. Compared to monometallic Ni, the DDO path become dominant on Ni–Ce and Ni–Co and the selectivity for BTX products increased from 58.8% to 77.4% and 71.1%, respectively. The binary metal Sn, unlike the former two metals, formed a Ni3Sn crystal form with Ni, which resulted in significant enhancement of the HYD path while obviously increasing the reactivity.

One-pot synthesis of 1,5-benzodiazepine-2,3-dicarboxylates via three-component domino reactions in the presence of γ-Fe2O3@SiO2/Ce(OTf)3

An Xiaoying,Gao Lei,Wang Mingliang,Wu Haitao,Wang Lanzhi

Novel, efficient and environmentally friendly approaches have been developed for the synthesis of 1,5-benzodiazepine-2,3-dicarboxylates by one-pot three-component domino reactions in the presence of a catalytic amount of γ-Fe 2 O 3 @SiO 2 /Ce(OTf) 3 in EtOH at ambient temperature. A total of 32 2,5-dihydro-1 H -1,5-benzodiazepine-2,3-dicarboxylates and 2-methyl-2,3-dihydro-1 H -1,5-benzodiazepine-2,3-dicarboxylates with enamine or imine structure of the heterocycle, respectively, were obtained in good yields by reacting substituted 1,2-phenylenediamine, β-carbonyl esters, and ethyl glyoxylate or ethyl pyruvate. One-pot reactions were successfully realized to form one new cycle and four new bonds (one C–C, two C–N, one C=C or two C–C, one C–N, one C=N). Furthermore, plausible mechanisms for the formation of 1,5-benzodiazepine-2,3-dicarboxylates have been proposed. The salient features of this reaction include short reaction time, mild reaction conditions, moderate to excellent yields, recyclability of the catalyst, and wide substrate scope.