Silane Compound Research Articles

Effect of The Amount of 3-(trimethoxysilyl) propyl methacrylate on Improving Surface’s Adhesive Properties of Zirconia

Abstract The objective of this research was silanize zirconium oxide (ZrO2) nanoparticles with 3-(trimethoxysilyl) propyl methacrylate (γ -MPS). Silanization is a surface treatment process of a material using silane compounds to improve the surface adhesive and compatibility of ZrO2 with other materials or coatings and to modify its surface. The surface modification of ZrO2 by 3-(trimethoxysilyl) propyl methacrylate as coupling agents under the influence of ultrasonic waves. The silanized ZrO2 was characterized Fourier Transform Infrared Spectroscopy (FTIR) and thermogravimetric analysis (TGA). The FTIR analysis indicated the interaction of the silane compound on the ZrO2 surface, showing characteristic peaks corresponding to Zr-OH, C-H stretching, carbonyl groups, and Zr-O-Si bonds, indicating successful grafting. The FTIR spectra for the ZrO2 nanoparticles, showing peaks at 1088 cm−1 showed the formation of Zr-O-Si covalent bonds. ZrO2 nanoparticles also exhibited a characteristic peak at 400 cm−1, indicating the deformation of Zr-O-Zr bonds. C=C, and C=O peaks are observed in the range of 1632-1714 cm−1. Thermogravimetric analysis (TGA) measures showed a higher weight loss of the silanized ZrO2 when higher amounts of silane were added.

Production of nanocomposite films based on low density polyethylene/surface activated nanoperlite for modified atmosphere packaging applications

The modified atmosphere packaging films based on polyethylene nanocomposites reinforced with perlite nanoparticles were prepared using a blow molding machine. The perlite particles were first reduced to nano dimensions using an abrasive mill, then the porosity of nanoperlite was increased to improve their efficiency in absorbing ethylene gas. For this purpose, 6 normal sodium hydroxide solution at 50°C temperature was used. Finally, perlite nanoparticles were modified by polymethyl hydrogen siloxane silane compound. In each of the stages of grinding and modifying the perlite surface, the necessary tests including dynamic light diffraction test, nitrogen absorption test and ethylene gas absorption test were performed using gas chromatography method. The results showed that the size of perlite particles was reduced to 500 nm by using an abrasive mill, and the surface modification process increased the specific surface area of perlite by 10 times. Based on this, the amount of ethylene gas absorption in perlite nanoparticles with modified surface increased up to 3 times compared to normal perlite. The results of the gas chromatography test showed that the nanocomposite film based on polyethylene reinforced with 6% by weight of modified perlite nanoparticles has several times the efficiency in absorbing ethylene gas compared to the potassium permanganate sachets The results of the mechanical properties tests of nanocomposite film in comparison with pure polyethylene film showed that nanocomposite film has higher properties than pure polyethylene. The results of shelf-life tests of green tomatoes packed in nanocomposite film based on polyethylene reinforced with modified nanoperlite showed that green tomatoes can be stored for two months using the prepared modified atmosphere packaging.

Wool fiber as an In situ reducing agent towards ZnO-based surface modified fabric development: Durability assessment in the realm of textile applications

The development of a bio-inspired method to fabricate ZnO nanostructure-modified functional wool fabric represents a substantial challenge in the textile field. This article reports for the first time the use of wool as a reducing agent for the synthesis of ZnO nanoparticles. While previous studies have employed alternative natural reducing agents for surface modification of host materials, this investigation uniquely utilizes the host material, wool, as the reducing agent for in-situ ZnO nanoparticle synthesis. In addition to demonstrating the use of wool as a reducing agent, this literature uniquely reports the durability of the modified fabric, achieved through the use of trimethoxy methyl silane. This silane compound acts as a bridging agent, forming a strong interface between the wool fibers and the synthesized ZnO nanoparticles. This innovative approach enhances the adhesion and stability of the ZnO nanoparticles on the wool fabric, a key aspect that contributes to the overall durability and performance of the modified material. The in situ surface modification process employed a metal oxide precursor (zinc acetate dihydrate), capping agents (hexamethylene tetraamine, sodium carbonate, and sodium sulfate), and a coupling agent (trimethyl methoxy silane). The capping agents were used to control the reaction conditions, while the coupling agent was employed to improve the durability of the surface modification. The impact of three different capping agents on the corresponding synthesis process was assessed, and the findings revealed that the choice of capping agent helped to form ZnO nanoparticles with distinct morphologies. Analytical techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), dynamic light scattering (DLS), and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, were utilized to characterize the synthesized particles and the treated fabric. The XRD analysis coupled with SEM analysis confirmed the successful formation of ZnO nanoparticles. The ATR-FTIR spectroscopy provided evidence of the formation of Si-O-Zn and Si-O-C bonds, observed at around 920 cm−1 and 1040 cm−1 respectively. These spectroscopic findings indicate that the surface modification involving the silane compound has enhanced the durability of the ZnO-modified fabric. The covalent linkages between the ZnO nanoparticles, the silane compound, and the wool fibers, confirmed by SEM analysis before and after washing cycles, have enabled the durable attachment of the nanoparticles to the fabric surface, even after multiple washing cycles. The results suggest a novel pathway to use wool as a reducing agent for the surface modification of the same material. Detailed mechanistic insights into the surface modification process and the corresponding chemical interactions were also discussed.

An eugenol-based siloxane resin with low viscosity, low dielectric constant, and high mechanical properties

One of the most prominent research topics currently is the development of a multi-functional, low-viscosity epoxy resin with exceptional flame retardancy, high strength, high toughness, low dielectric loss, and hydrophobicity. This resin holds significant potential for applications in the fields of electronics and electricity. However, achieving all these properties simultaneously poses a considerable challenge. To address this problem, a new epoxy resin with symmetrical structure containing silica was designed using dichlorodiphenyl silane and biobase compound eugenol as raw materials through molecular design. Comparative analysis with DGEBA/DDM revealed that ESR/DDM exhibits a remarkable increase in Young's modulus by 57.5 % and impact strength by 132.1 %. Moreover, within a wide frequency range (10–106 Hz), ESR demonstrates lower dk values (0.75–0.95) compared to DGEBA (3.3–3.5), indicating reduced absorption of electric energy under alternating electric fields' influence. The contact angle of ESR/DDM epoxy material measures at 113.56° - an impressive enhancement of 29.8 % compared to DGEBA/DDM counterparts. In summary, ESR represents a hydrophobic material possessing low viscosity, low dielectric constant, and superior mechanical properties. The findings of this study offer a novel perspective for advancing the development of bio-based epoxy resins with enhanced performance and multifunctionality.

Synthesis of Aptes-Capped Self-Adsorption Pd Nanoparticles and Application in Metallization on Glass Substrate with High Adhesion

Palladium is the most used catalysts in the electroless deposition process. The technology that use the amino silane compound (3-Aminopropyl) Triethoxysilane (APTES) as surface modifier is quite mature. Therefore, an innovative idea that one step palladium catalyst APTES-Pd with APTES as capping agent and surface modifier appeared. APTES-Pd is capable to adsorb on surface of glass substrate by forming Si-O covalent bond. Comparing to commercial palladium catalysts, the process is complex and need to work at high concentration, APTES-Pd has easier process and able to work at low concentration. The particle size of APTES-Pd is characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The configuration of APTES-Pd as well as the effect of modification on glass substrate is explained by X-ray photoelectron spectroscopy (XPS).Glass substrate is a good option as an interposer substrate. It has serval advantages, such as low k, high resistivity, high stability, low coefficient of thermal expansion (CTE) mismatch with copper material and good mechanical properties. However, because glass substrate (SiO2) is stable and surface is smooth, it’s hard to electroless deposit Cu layer with high adhesion on it. The adhesion that using commercial palladium catalysts Sn/Pd for electroless copper deposition is too low to pass tape test. Because interaction between Sn/Pd and substrate is electrostatic adsorption which is lower than covalent bond. Using APTES-Pd for electroless copper deposition is capable to improve the interaction between glass and Cu layer. APTES-Pd can pass tape test on glass substrate. But its adhesion is still too low to be measured by T-Peel. To enhance the adhesion of the metal films on glass substrates, we coat titanium dioxide (TiO2) as adhesion promoter. TiO2 can not only bond to glass substrate but increase surface roughness. After coating TiO2 film, the adhesion of metal film increases to 122 gf/cm.

Bifunctional modification of graphene by phosphorus/nitrogen‐containing silane compounds for smoke suppression and flame retardancy of epoxy resins

AbstractEnhancing the flame retardancy with minimal impact on the mechanical and thermal performances of polymers remains a challenge. This study synthesized a phosphorus/nitrogen‐containing silane compound (D) using polyformaldehyde, KH‐550, and 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) as raw materials through the Kabachnik‐Fields reaction. After that, D was grafted onto the surface of graphene after hydrothermal treatment to obtain a nano hybrid flame retardant (D‐GR). And D‐GR/EP composites exhibited good flame resistance (LOI = 30.1% and UL‐94 reaches the V‐1 rating) even if the load on D‐GR was 1 wt%. Indeed, the total heat release, the peak heat release rate (PHRR), and the total smoke release of 1% D‐GR/EP dropped by 13.54%, 28.62%, and 44.32%, respectively, in comparison to pure EP. The mechanical performance of 1% D‐GR/EP was effectively maintained, as indicated by the results of impact, tensile and flexural tests. A systematic evaluation indicated that the accession of D‐GR effectively inhibited smoke and heat releases that are ascribed to the synergistic effect of phosphorus/nitrogen‐containing silane compound and graphene. In this study, a facile method was provided for the synthesis of halogen‐free flame‐retardant epoxy composites with superior performances. The combustion products of the as‐prepared composites complied with green and environmental protection standards.

Designable Poly(methacrylic Acid)/Silver Cluster Ring Arrays as Reflectance Spectroscopy-Based Biosensors for Label-Free Plague Diagnosis.

A hole array was fabricated via photolithography to wet the bottoms of holes using oxygen plasma. Amide-terminated silane, a water immiscible compound before hydrolysis, was evaporated for deposition on the plasma-treated hole template surface. The silane compound was hydrolyzed along the edges of circular sides of the hole bottom to form a ring of an initiator after halogenation. Poly(methacrylic acid) (PMAA) was grafted from the ring of the initiator to attract Ag clusters (AgCs) as AgC-PMAA hybrid ring (SPHR) arrays via alternate phase transition cycles. The SPHR arrays were modified with a Yersinia pestis antibody (abY) to detect the antigen of Yersinia pestis (agY) for plague diagnosis. The binding of the agY onto the abY-anchored SPHR array resulted in a geometrical change from a ring to a two-humped structure. The reflectance spectra could be used to analyze the AgC attachment and the agY binding onto the abY-anchored SPHR array. The linear range between the wavelength shift and agY concentration from 30 to 270 pg mL-1 was established to obtain the detection limit of ~12.3 pg mL-1. Our proposed method provides a novel pathway to efficiently fabricate a ring array with a scale of less than 100 nm, which demonstrates excellent performance in preclinical trials.

Poly[2-(dimethylamino)ethyl methacrylate]/gold nanoparticle composite dual-stripe nanowire arrays as optical biosensors for label-free plague diagnosis

BackgroundMost commercial kit provides a meager limit of detection of 104 CFU/mL. Antigen determination remains an urgent need for further development of rapid, sensitive, and reliable diagnostic methods for use at the point of need. MethodsAmide-terminated silane, a water immiscible compound before hydrolysis, was evaporated for deposition on the alternative wetting and dewetting regions. The silane compound was hydrolyzed along the interfaces of wetting and dewetting regions to form a dual-stripe of an initiator after halogenation. Poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) was grafted from the dual-stripe of the initiator to attract gold nanoparticles (AuNPs) as AuNP-PDMAEMA composite dual-stripe nanowire (APDW) arrays via alternate phase transition cycles. The APDW arrays were modified with a Yersinia pestis (abY) antibody to detect the antigen of Yersinia pestis (agY) for plague diagnosis. Significant findingsThe binding of the agY onto the abY-anchored APDW array resulted in a geometrical change from a dual-stripe to a two-humped structure. The reflectance spectra could be used to analyze the AuNP attachment and the agY binding onto the abY-anchored APDW array. The linear range between the wavelength shift and agY concentration from 20 to 440 pg mL−1 was established to obtain the detection limit of ∼14.2 pg mL−1.

Full-color micro-LED display with photo-patternable and highly ambient-stable perovskite quantum dot/siloxane composite as color conversion layers

In this paper, we successfully fabricated color conversion layers (CCLs) for full-color-mico-LED display using a perovskite quantum dot (PQD)/siloxane composite by ligand exchanged PQD with silane composite followed by surface activation by an addition of halide-anion containing salt. Due to this surface activation, it was possible to construct the PQD surface with a silane ligand using a non-polar organic solvent that does not damage the PQD. As a result, the ligand-exchanged PQD with a silane compound exhibited high dispersibility in the siloxane matrix and excellent atmospheric stability due to sol–gel condensation. Based on highly ambient stable PQD/siloxane composite based CCLs, full-color micro-LED display has a 1 mm pixel pitch, about 25.4 pixels per inch (PPI) resolution was achieved. In addition, due to the thin thickness of the black matrix to prevent blue light interference, the possibility of a flexible display that can be operated without damage even with a bending radius of 5 mm was demonstrated.

Characterization of [1]Benzothieno[3,2-b]benzothiophene (BTBT) Derivatives with End-Capping Groups as Solution-Processable Organic Semiconductors for Organic Field-Effect Transistors

Solution-processable [1]benzothieno[3,2-b]benzothiophene (BTBT) derivatives with various end-capping groups, 2-(phenylethynyl)benzo[b]benzo[4,5]thieno[2,3-d]thiophene (Compound 1), 2-octyl-7-(5-(phenylethynyl)thiophen-2-yl)benzo[b]benzo[4,5]thieno[2,3-d]thiophene (Compound 2), and triisopropyl((5-(7-octylbenzo[b]benzo[4,5]thieno[2,3-d]thiophen-2-yl)thiophen-2-yl)ethynyl)silane (Compound 3), have been synthesized and characterized as active layers for organic field-effect transistors (OFETs). Thermal, optical, and electrochemical properties of the newly synthesized compounds were characterized using thermogravimetric analysis (TGA), a differential scanning calorimeter (DSC), UV–vis spectroscopy, and cyclic voltammetry (CV). Thin films of each compound were formed using the solution-shearing method and the thin film surface morphology and texture of the corresponding films were characterized using atomic force microscopy (AFM) and θ–2θ X-ray diffraction (XRD). All semiconductors exhibited p-channel characteristics in ambient and Compound 1 showed the highest electrical performance with a carrier mobility of ~0.03 cm2/Vs and current on/off ratio of ~106.

Study on Modified Liquid Polysulfide Rubber Bimetallic Salt-Spray-Resistant Epoxy Coatings

In this study, liquid polysulfide rubber was modified by silane coupling agent. New kinds of anti-corrosion coatings with salt spray resistance and strong adhesion to the steel substrate were obtained using the modified liquid polysulfide rubber, bimetallic filler, carbon nanotubes, and epoxy resin. Infrared and nuclear magnetic resonance confirmed the preparation of new modified liquid polysulfide rubber through coupling reaction between the epoxy group of silane compound and the sulfide group of the liquid polysulfide rubber. A 1440 h neutral salt spray test showed the coating to be completely free of rust and blisters. The corrosion diffusion width of the scribed area was only 1.7 mm. In addition, in a 3.5% by weight NaCl solution, the coating shows no blistering and no corrosion phenomena compared with zinc-rich epoxy paints (the added zinc content was only 28.6%). These tests confirmed that the new coating had a dense microstructure, strong adhesion to the steel substrate, good corrosion resistance, and anti-blister performance. The performance indicates that the coatings have potential for use in the atmosphere and underwater, which provides a better choice for long-term protection of marine projects such as ships, wharves, offshore platforms, and wind power structures.

Proposing a sustainable strategy for the fabrication of robust anti-soiling coatings with enhanced antibacterial attributes for non-absorbent substrates

In this paper, we propose a convenient methodology for fabricating a generic structure toward developing a robust, easy-to-clean transparent coating with inherent antibacterial properties for smooth, non-absorbent surfaces, such as glass and plastics. A two-step coating comprising an organopolysilazane primer and an alkoxysilane topcoat, based on positively charged quaternary ammonium silanes, is proposed. The topcoat is co-condensed with the primer to provide a hybrid structure with high wear strength even on surfaces that lack surface hydroxyl groups. Surfaces examined included glass and PMMA. The coated samples were studied in terms of abrasion resistance as well as anti-soiling and antimicrobial performance. It was found that the quaternary silane compound could covalently graft onto the primer acting both as an antibacterial, anti fungicidal, and hydrophobizing agent. The utility of amphoteric surfactants within the coating’s solution was also examined. The resulting structure was transparent and exhibited pronounced self-disinfecting properties with remarkable sustainability. These attributes suggested a dual functionality of the coating, i.e., both anti-soiling and antimicrobial, thus rendering it a potential candidate for numerous industrial and commercial applications.

Thermal, Magnetic and Electrical Properties of PMMA Nanocomposites with Manganese and Zinc Ferrite Nanoparticles and Their Functionalization

AbstractManganese (MnFe2O4) and zinc (ZnFe2O4) ferrite nanoparticles were synthesized by the combustion method. Furthermore, the modification of these particles with a silane compound was performed. Thus, the particles produced were analyzed for morphology using Scanning electron microscopy (SEM), thermal stability, and composition assisted by Thermogravimetric analysis (TGA). It is noteworthy that the present work used an unprecedented Far‐Fourier‐transform infrared spectroscopy (Far‐FTIR) technique to differentiate the types of ferrites and their surface functionalization, as it is a simpler, more efficient, and high‐resolution method. It is worth mentioning that there are few comparative studies of zinc and manganese ferrites in the literature, much less distinguishing these ferrites simply and efficiently. In addition, there is also a lack of scientific knowledge about its chemical functionalization as compatibilization, especially silanization. Novel PMMA nanocomposites were prepared with the different synthesized particles in the contents from 0.1 % to 1.0 wt.% by the in situ polymerization technique. The nanocomposites were characterized by the analysis of SEM, TGA, Differential scanning calorimetry (DSC), and FTIR mainly by their morphology, thermal resistance, glass transition temperature, proving the chemical interactions, electrical conductivity, capacitance, and dielectric constant. Furthermore, it was evidenced that, in addition to the improvements in thermal, electrical, and interface properties, the produced nanocomposites showed excellent electromagnetic shielding properties even at low filler contents. It is noteworthy that the capacitance increases 63 % for the composite with 1.0 % zinc ferrite and 43 % for manganese ferrite. Also, the electromagnetic absorption results proved that even the low filler contents tested in this work, up to 1.0 %, presented an excellent potential for applying as electromagnetic shielding materials, reaching up to 70 % attenuation with the use of zinc ferrite. Both ferrites showed excellent results, even superior to those found in the literature for other particles with the same purposes, and still needed a lower content to achieve excellent results.

Microfibrous cyclodextrin boosts flame retardancy of poly(lactic acid) II - phosphorous silane treatment further enhances the effectivity

Recently, the flame retardant effectiveness of a 2-hydroxypropyl-β-cyclodextrin (CD) type bio-based carbonising agent has been evinced to noticeably increase when used in a microfibrous form, as obtained by electrospinning method. In the present research, the flame retardant performance of the electrospun CD was further enhanced by reactive surface modification with a phosphorous silane (PSil) compound. Surface-treated and untreated CD-based carbonising agents were compared, both in powder and in microfibrous form, besides ammonium polyphosphate (APP) to form an intumescent flame retardant system for poly(lactic acid) (PLA). The Limiting Oxygen Index (LOI) of the flame-retarded PLA composites increased outstandingly, from 25.0% (corresponding to the 15 wt% APP containing PLA) to as high as 37.5%, as a result of adding only 3 wt% of PSil-treated microfibrous CD to the system. Also, the main combustion characteristics improved; compared to neat PLA, about 50% reduction in the peak heat release rate (pHRR) and 25% reduction in total heat release (THR) were achieved, accompanied by an increased amount of char residue after combustion. The beneficial effect of the PSil-treated CD microfibre relies mainly on its enhanced physical and chemical interaction with APP and its increased charring ability and thermal stability, which contribute to the formation of a fire protecting char of increased structural integrity.

Tethered Bilayer Membrane Formation on Silanized Fluorine Doped Tin Oxide Surface

Silane compound was synthesized via click chemistry and a mixture of synthesis products without purification was used to form the self-assembled monolayers on metal oxide conducting films of fluorine doped tin oxide (FTO). Silanized FTO surfaces triggered rupture of multilamellar vesicles and formed electrically insulating tethered bilayer membranes (tBLMs). In contrast to well-known hybrid bilayer membranes on silane monolayers such as ones formed from octadecyltrichlorosilane, tBLMs on FTO contained water-ion reservoir between solid surface and phospholipid bilayer sheet. They demonstrated biological relevance and ability to reconstitute the pore-forming protein channels such as α-hemolysin from Staphylococcus aureus and melittin. The addition of cholesterol to tBLMs decreased the membrane-damaging effect of melittin, while the opposite was observed in the case of α-hemolysin. The tBLMs can be regenerated multiple times without losing their functionality. The described methodology (both synthesis and formation of anchor monolayer) can be extended to any oxide film surface by properly adjusting chemical composition of molecular anchor and silanization conditions. This makes the proposed biomimetic membrane system attractive for various applications including biomedical sensors for the detection of pore-forming toxins.

Zwitterionic polysiloxane-polyamide hybrid active layer for high performance and chlorine resistant TFC desalination membranes

• Zwitterionic polysiloxane-PA hybrid active layer TMC on the PS support layer was prepared. • SPPT was synthesized by the reaction of DMAPS with 1,3-propane sulfone. • Chlorine resistance of fabricated membrane increased from 2 h to 6 h. • Salt rejection slightly increased from 98.8% to 98.9%. Hybrid polysiloxane-polyamide thin-film composite (TFC) reverse osmosis (RO) membranes were produced in the presence of a zwitterionic silane compound during polyamide active layer preparation by interfacial polymerization for an enhanced desalination performance and chlorine resistance. The zwitterionic functional silane monomer, (3-sulfopropylbetaine-propyl)-trimethoxysilane (SPPT), was added to an aqueous m-phenylenediamine (MPD) monomer solution at different concentrations; 0.05, 0.1, 0.25, 0.5 and 1.0 SPPT/MPD ratios. The aqueous monomer solutions adsorbed on a polysulfone support layer were contacted with an organic trimesoyl chloride (TMC) monomer solution to create a polysiloxane-polyamide hybrid active layer by interfacial polymerization. Hybrid active layers were characterized by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), water contact angle (WCA), and zeta potential measurements. Membranes produced with a SPPT/MPD ratio of 0.1 exhibited an increase in permeate flux from 25 L m −2 h −1 to 33 L m −2 h −1 (55 bar operating pressure; 3.2% NaCl feed) while the salt rejection was not compromised, but slightly increased from 98.8% to 98.9%, when compared to the control membrane prepared without SPPT. The highest resistance against chlorine was observed for the membranes produced with a SPPT/MPD ratio of 1.0, for which, a significant membrane damage and consequent loss of salt rejection were observed after six hours of exposure to chlorine solution, while the control membrane was prone to chlorine damage after two hours.

One-step synthesis of quaternized silica nanoparticles with bacterial adhesion and aggregation properties for effective antibacterial and antibiofilm treatments.

Preservation of the intact cell morphology of bacteria is recognized as one important cause of bacterial drug resistance, and hence developing new antibacterial agents capable of fighting against bacteria via disrupting their cell envelope is highly desirable. Herein, by adopting a modified Stöber method, we developed a one-step approach to fabricate quaternized silica nanoparticles (NPs) using two commercially available molecules-a long alkyl chain-bearing quaternary ammonium silane compound, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (Si-QAC), and tetraethyl orthosilicate (TEOS). Specifically, small spherical quaternized silica NPs with an average size of ∼34 nm could be prepared at a TEOS/Si-QAC molar ratio of 4 : 1 with a very high yield (>90%), and the resultant NPs (termed TS4 NPs) possessed superb colloidal stability (at least 520 d) and good biocompatibility. In addition, we confirmed that the long alkyl chain (C18)-bearing quaternary ammonium group endowed the TS4 NPs with the capacity to efficiently kill negatively charged Gram-positive bacteria via both hydrophobic and electrostatic interactions. Specifically, the TS4 NPs could coat the Staphylococcus aureus (S. aureus) cells via densely binding to the bacterial surface and induce the formation of TS4-S. aureus aggregates to exert their membrane disruption and reactive oxygen species (ROS) production effects, leading to the breakage of intracellular DNA and bacterial death. Besides, we revealed that TS4 could eradicate the mature S. aureus biofilms and inhibit the formation of S. aureus biofilms. The present work proposes a simple one-step method to prepare quaternized silica NPs with excellent bacterial adhesion and aggregation properties, which will find practical applications to fight against infections caused by bacteria and their biofilms.

Mechanical, Morphological, Thermal and Dynamic Study of Composites of Unsaturated Polyesters-Date Palm Leaf Fiber DPLF

In order to improve the properties of unsaturated polyesters, this study discusses the possibilities of developing a natural waste, date palm leaf fiber DPLF, produced in the northern Algerian Sahara, associated with the polymer matrix of a thermosetting polyester resin UP. For this purpose, composite plates containing virgin fiber at rates of 6 and 10% were treated with an alkaline solution of 6% NaOH on the one hand, and a silane compound on the other. In this research, a mechanical study of strength and elongation at break was carried out. In addition, morphological behavior was followed by SEM scanning electron microscopy. ATG thermogravimetric analysis and energy flow were monitored by DSC differential scanning calorimetry. Also, a study of the water absorption capacity has been conducted. In addition, a dynamic mechanical analysis DMA was carried out. The findings of this study show that there is a favorable mechanical behavior for the composites containing the 6% and 10% DPLF fiber, with alkaline NaOH and Silane treatment. They also show that the chemical treatment with alkaline solution and silane gives composites certain thermal stability compared to those with untreated fiber. Findings also explore that the absorption of water by the various composites shows that the chemical treatment promotes some intermolecular associations with water. Findings also show that the storage modulus (E') increases when the composite contains 10% DPLF, treated and untreated, and the maximum value of the tangent moves towards the high temperature for the treated and untreated fiber composite.

3D‐printed surface‐modified aluminum nitride reinforced thermally conductive composites with enhanced thermal conductivity and mechanical strength

AbstractWith the rapid miniaturization of electronic devices, novel thermally conductive composite materials are required for efficient thermal management. In this study, a straightforward strategy to fabricate thermally conductive composites, based on UV‐curable acrylate polymer using the DLP technique, was explored. Aluminum nitride (AlN), a ceramic filler with high thermal conductivity and mechanical strength, was functionalized with an acrylate bearing silane compound. This improved the interfacial adhesion between the filler and matrix, resulting in enhanced thermal conductivity. The thermal conductivity of the composite with 30 wt.% modified AlN was 0.42 W/mK, which is 3.5 times higher than that of neat UV‐cured acrylate resin (0.12 W/mK). The tensile strength also increased from 13.9 to 20.8 MPa before and after surface treatment due to improved filler‐matrix compatibility. The study demonstrates that 3D‐printing can be easily integrated into the fabrication of thermally conductive composites and filler surface modification can effectively enhance the thermal and mechanical strength of the composite.

Efficient Chemical Surface Modification Protocol on SiO2 Transducers Applied to MMP9 Biosensing.

The bioreceptor immobilization process (biofunctionalization) turns to be one of the bottlenecks when developing a competent and high sensitivity label-free biosensor. Classical approaches seem to be effective but not efficient. Although biosensing capacities are shown in many cases, the performance of the biosensor is truncated by the inefficacious biofunctionalization protocol and the lack of reproducibility. In this work, we describe a unique biofunctionalization protocol based on chemical surface modification through silane chemistry on SiO2 optical sensing transducers. Even though silane chemistry is commonly used for sensing applications, here we present a different mode of operation, applying an unusual silane compound used for this purpose (3-Ethoxydimethylsilyl)propylamine, APDMS, able to create ordered monolayers, and minimizing fouling events. To endorse this protocol as a feasible method for biofunctionalization, we performed multiple surface characterization techniques after all the process steps: Contact angle (CA), X-ray photoelectron spectroscopy (XPS), ellipsometry, and fluorescence microscopy. Finally, to evidence the outputs from the SiO2 surface characterization, we used those SiO2 surfaces as optical transducers for the label-free biosensing of matrix metalloproteinase 9 (MMP9). We found and demonstrated that the originally designed protocol is reproducible, stable, and suitable for SiO2-based optical sensing transducers.