And 3-aminopropyltriethoxysilane Research Articles

A Humidity‐Insensitive Waterborne Polyurethane Pressure‐Sensitive Adhesive Modified by Castor Oil and Siloxane

AbstractAlthough waterborne polyurethane pressure‐sensitive (PSA) has achieved great progress, achieving robust effective adhesion on the wet substrate surface is still challenging. Herein, we developed a humidity‐insensitive waterborne polyurethane pressure‐sensitive adhesive through the modification of bio‐based castor oil and 3‐aminopropyl triethoxysilane (APTES) as the end‐capper. Improved bonding property on wet substrate via drainage of hydrophobic groups led to better humidity‐insensitive adhesiveness. The results exhibited exceptional bonding performance (∼3.3N/25 mm) on the moist surface of the steel in the environment with a humidity of 100 % RH (Relative Humidity). Especially, the 180° peel forces of siloxane‐terminated castor oil‐based waterborne polyurethane (SCWPU) respectively enhanced by 13.33 % and 73.68 % compared with the blank sample when the air humidity increased from 50 % RH to 100 % RH. Silicone had the advantages of low surface energy, good heat resistance and good oxidation resistance. The heat resistance could be improved by introducing silicone into waterborne polyurethane. Tested by the TGA, the SCWPU3 PSA demonstrated great thermal stability (THRI=144.32 °C). Besides, the PSA also exhibited low water absorption (20.6 %), and eligible viscoelasticity properties. These findings provided an impetus for the development of humidity‐insensitive PSA.

Modified Activated Carbon: A Supporting Material for Improving Clostridium beijerinckii TISTR1461 Immobilized Fermentation.

This study aimed to investigate the effect of activated carbon (AC) as an immobilization material in acetone-butanol-ethanol fermentation. The AC surface was modified with different physical (orbital shaking and refluxing) and chemical (nitric acid, sodium hydroxide and, (3-aminopropyl)triethoxysilane (APTES)) treatments to enhance the biobutanol production by Clostridium beijerinckii TISTR1461. The effect of surface modification on AC was evaluated using Fourier-transform infrared spectroscopy, field emission scanning electron microscopy, surface area analyses, and X-ray photoelectron spectroscopy, while the fermented broth was examined by high-performance liquid chromatography. The chemical functionalization significantly modified the physicochemical properties of the different treated ACs and further enhanced the butanol production. The AC treated with APTES under refluxing provided the best fermentation results at 10.93 g/L of butanol, 0.23 g/g of yield, and 0.15 g/L/h of productivity, which were 1.8-, 1.5-, and 3.0-fold higher, respectively, than that in the free-cell fermentation. The obtained dried cell biomass also revealed that the treatment improved the AC surface for cell immobilization. This study demonstrated and emphasized the importance of surface properties to cell immobilization.

Humic-Based Polyelectrolyte Complexes for Dust Suppression.

The present study proposes a novel application of humic substance-aminosilsesquioxane polyelectrolyte complexes (HS-ASQ) as dust suppressants. These complexes are synthesized through the reaction between humic substances (HS) and 3-aminopropyltriethoxysilane (APTES) in aqueous solution, resulting in the formation of active silanol groups that can bind to mineral surfaces and condense, forming gels. The HS-ASQ compositions were found to have a high sorption capacity for dust particles and could form coatings on their surface without cementing the dust, making them potentially useful for environmental applications. The viscosity of the HS-ASQ compositions can be controlled by adding carboxymethylcellulose (CMC), which also enhances their dust suppression abilities. Different compositions of HS-ASQ were synthesized by varying the proportions of APTES and CMC, and dust treated with these samples was assessed for its resistance to wind erosion using a laboratory-scale setup. Treatment with the HS-ASQ composition resulted in substantial reductions in PM10 and PM2.5 concentrations (particulate matter with aerodynamic diameters of 10 µm and 2.5 µm, respectively) of up to 77% and 85%, respectively, compared to the control.

Silane-modified graphene oxide in geopolymer: Reaction kinetics, microstructure, and mechanical performance

Graphene oxide (GO) and 3-aminopropyltriethoxy silane (APTS) have been successfully used in geopolymers to solve specific problems. Nevertheless, the dispersion of GO to strengthen the matrix remains a challenge owing to the characteristic high alkalinity of geopolymer binders. Concurrently, independent addition of APTS to improve the workability severely retards geopolymer dissolution and condensation reactions. In this paper, an attempt is made to mutually exploit benefits of these two additives through a surface functionalisation approach whereby surface functional groups of GO were modified by APTS to provide repulsive effects that could better isolate the GO nanosheets from each other, while the accelerating effects of GO on the geopolymerisation process compensated for the retardation effects of APTS. The structure of GO-APTS was observed to be stable in the highly alkaline sodium silicate environment and significantly improved the dispersion of the nanosheets in the geopolymer composite according to the UV–Vis and SEM/TEM observations. Furthermore, the nucleation and reinforcing effects of GO were enabled by APTS. The GO-APTS–cement samples not only demonstrated better workability and transport properties compared with the reference and pure GO samples, but also superior mechanical strength, with improvements in tensile strength of ∼110% and ∼52% at 7 and 28 days, respectively. These findings evidence the effectiveness and potential of silane-functionalised GO in overcoming the dispersion issues experienced by GO in the highly alkaline media of geopolymers while simultaneously enhancing the mechanical and durability performance of geopolymer systems.

Multifunctional Superamphiphobic Cotton Fabrics with Highly Efficient Flame Retardancy, Self-Cleaning, and Electromagnetic Interference Shielding

Here, a facile method is reported to prepare multifunctional cotton fabrics with high flame retardancy, high electrical conductivity, superamphiphobicity, and high electromagnetic shielding. The cotton fabric surface was first modified with phytic acid (PA), which promoted dehydration and carbonization of cellulose to increase flame retardancy in the process of pyrolysis. Tannic acid (TA) and 3-aminopropyltriethoxysilane (APTES) coating with nanospheres as interlayers created hierarchical roughness that facilitated the construction of superamphiphobic surfaces and provided adhesion sites for silver nanoparticles. In addition, the TA-APTES coating improved flame retardancy because the APTES-containing silicon could form silicon carbon layers to isolate heat and oxygen. Subsequently, the surface energy of the composite cotton fabric was reduced by fluorine-containing molecules. The prepared composite cotton fabric exhibited excellent superamphiphobicity with contact angles of 160.3 and 152° for water and olive oil, respectively. The conductivity and EMI shielding efficiency of the prepared composite cotton fabric reached 629.93 S/cm and 76 dB, respectively. Importantly, the composite cotton fabric maintained a relatively stable EMI shielding efficiency even after cyclic bending and abrasion tests. Moreover, the composite cotton fabric possessed a high limiting oxygen index (LOI) of 45.3% and self-extinguishing properties with the peak heat release rate (PHHR) and total heat release (THR) reduced by 73 and 67%, respectively, than the pure cotton fabric, indicating the outstanding flame retardancy.

Efficient catalytic hydrogen generation from formic acid dehydrogenation on ultrafine PdAu nanoparticles supported on modified carbon derived from rice straw

Formic acid (FA) dehydrogenation at ambient conditions is a promising route for hydrogen (H2) generation but still suffers from low activity and selectivity. Here, potassium hydroxide (KOH) and 3-aminopropyl triethoxysilane (APTES) modified porous carbon derived from the pyrolysis of rice straw (RSNPC) offers an effective support to promote the formation of ultrafine PdAu nanoparticles (NPs). Benefiting from the small sizes of PdAu NPs, the Pd0.7Au0.3/RSNPC catalyst exhibits excellent catalytic performance for FA dehydrogenation reaction with a high turnover frequency (TOF) of 6794.3 mol H2 mol catalyst−1 h−1 at ambient conditions, outperforming most of reported catalysts for FA dehydrogenation under similar conditions.

A statistical design approach to the sol-gel synthesis of (amino)organosilane hybrid nanoparticles.

This study comprehensively investigates the efficiency of the formulation of tetraethoxysilane (TEOS) and 3-aminopropyltriethoxysilane (APTES) copolymer in sol-gel syntheses as part of a multivariate experiment. A methodology-based response surface was used to estimate the influence of independent variables such as polymerization time and temperature, as well as the ratio of TEOS and APTES components on the surface charge response function and product yield, and in order to predict the best response values. Analysis of variance showed that when assessing the value of the zeta potential, the polymerization temperature and the ratio of components are statistically significant factors, but on the other hand, when assessing the yield of the finished product, only the ratio of components is significant. The combination of various options for temperature, time and ratio of components allows one to obtain a zeta potential in the range from +61.2 mV to -48.8 mV and a product yield of up to 4.7 g. Evaluation of the data with TGA-DTA, FTIR-ATR, and ELS methods showed an unexpected result, according to which the highest degree of polymerization and the highest surface charge were inherent in an amino-deficient system. Thus, the smaller the amino component in the system (the APTES-TEOS molar ratio is 0.25), the more efficient the polycondensation is over the absorption area of the Si-O-Si band, and the higher the zeta potential.

Plant-inspired biomimetic hybrid PVDF membrane co-deposited by tea polyphenols and 3-amino-propyl-triethoxysilane for high-efficiency oil-in-water emulsion separation

Membrane pollution caused by separating oily wastewater is a big challenge for membrane separation technology. Recently, plant-/mussel-inspired interface chemistry has received more and more attention. Herein, a high antifouling poly (vinylidene fluoride) (PVDF) membrane, coated with tea polyphenols (TP, extracted from green tea) and 3-amino-propyl-triethoxysilane (APTES), was developed to purify oil-in-water emulsions. ATR-FTIR, XPS and SEM were used to demonstrate the evolution of surface biomimetic hybrid coatings. The performances of the developed membranes were investigated by pure water permeability and oil rejection for various surfactant-stabilized oil-in-water emulsions. The experimental results revealed that the membrane deposited with a mass ratio of 0.1/0.2 exhibited ultrahigh pure water permeability (14570 L·m −2 ·h −1 ·bar −1 ) and isooctane-in-water emulsion permeability (5391 L·m −2 ·h −1 ·bar −1 ) with high separation efficiency (>98.9%). Even treated in harsh environment (acidic, alkaline and saline) for seven days, the membrane still maintained considerable underwater oleophobic property (148°∼153°). The fabricated plant-inspired biomimetic hybrid membranes with excellent performances light a broad application prospect in the field of oily wastewater treatment.

Superhydrophilic membrane with photo-Fenton self-cleaning property for effective microalgae anti-fouling

Membrane filtration is one of the effective approaches to harvest microalgae for industrial biofuel production. However, during the filtration process, microalgae cells and extracellular organic matter (EOM) will deposit on the membrane surface leading to reversible membrane fouling that can be removed by physical methods. When hydrophobic EOM is adsorbed on the membrane surface or inside pores, it will build up a gel layer, causing irreversible membrane fouling. Irreversible fouling can only be removed using chemical methods that will decrease membrane lifespan and increase operational costs. Here, we introduce a versatile superhydrophilic membrane with photo-Fenton self-cleaning property, which can prevent the reversible fouling and remove the irreversible fouling. Tannic acid (TA) and 3-aminopropyltriethoxysilane (APTES) were co-deposited on the polyvinylidene fluoride (PVDF) membrane via Schiff base and Michael addition reactions, and β-FeOOH nanorods were inlaid on the membrane surface by in situ mineralization. The water contact angle of the modified membrane is reduced from 120° to 0° Under 60 min visible light, the hydroxyl radical (·OH) generated by the photo-Fenton reaction degraded the irreversible fouling that blocked membrane pores. The irreversible fouling rates of modified membrane was reduced from 39.57% to 3.26%, compared with the original membrane. Microalgae harvesting results illustrated that the membrane has a high flux recovery rate (FRR) of 98.2%, showed excellent passive antifouling and active antifouling performance. We believe this work will spark a novel platform for optimizing energy-efficient microalgae harvesting separation membrane modules. In addition, this method of anti-fouling filtration for microorganisms can be extended to the industrial production of various bioenergy sources and will have very promising practical applications.

Construction of MOF-loaded polypropylene nonwoven fabrics for fast catalytic hydrolysis of chemical warfare agent simulants

• MOF-808/fiber composite was fabricated using tannic acid (TA) hybrid coating as the mediating layer. • The as-prepared MOF-808/fiber composite with 23.4 % MOF-808 displayed a high surface area (340 m 2 /g). • The obtained PP fabrics displayed a half-life of 1.3 min for dimethyl p -nitrophenyl phosphate (DMNP) degradation. • The PP@TA-APTES@MOF-808 catalyst has good stability for DMNP detoxification . Zirconium-based metal-organic frameworks (Zr-MOFs) have emerged as promising candidates for the catalyzed hydrolysis of nerve agents, but facile methods for their integration into textiles are still lacking. Herein, we report a strategy for the preparation of MOF-808-loaded polypropylene (PP) nonwoven fabrics mediated by a tannic acid (TA) and 3-aminopropyltriethoxysilane (APTES) hybrid coating (TA-APTES). The as-prepared PP nonwoven fabric displayed a rapid catalytic degradation rate for dimethyl p -nitrophenyl phosphate (DMNP) with a half-life of 1.3 min in a basic buffered condition.

Protective effect of silicone-modified epoxy resin coating on iron-based materials against sulfate-reducing bacteria-induced corrosion

The annual economic loss caused by microbiologically influenced corrosion (MIC) is over 140 billion US dollars worldwide. A sizable proportion (30 %) of MIC is caused by sulfate-reducing bacteria (SRB). Herein, a silicone-modified epoxy resin coating was designed with the aim of reducing the rate of SRB-induced corrosion. The epoxy resin (E-51) was modified with heptamethyltrisiloxane and 3-aminopropyltriethoxysilane (APTES). Compared to the pure epoxy coating (E-51), the modified coating (TAK550/E-51) had a better protective effect against acid- and SRB-induced corrosion owing to its macroscopic and microscopic morphology. Electrochemical impedance spectroscopy revealed that the impedance of TAK550/E-51 coating was 1.5-times higher than that of the E-51 coating, providing it with higher corrosion resistance. In addition, the TAK550/E-51 coating had a lower corrosion current density (icorr = 3.30 × 10−9 A·cm−2) and higher corrosion potential (Ecorr = −0.04 V) than the E-51 coating. The thermal stability of the TAK550/E-51 coating was improved compared to that of the pure epoxy resin coating, with a 9.2 °C higher initial decomposition temperature (T5%), 40.8 °C higher 50 % weight-loss temperature (T50%), and doubled carbon residue rate. The elemental composition and valence state of the coating surface were examined by X-ray photoelectron spectroscopy after immersion in SRB-containing solution for different time periods, which revealed the antibacterial and anticorrosion mechanisms of the TAK550/E-51 coating. The results reported in this paper demonstrate that the silicone-modified epoxy coating has good MIC resistance and can be used as a protective coating for iron-based materials that are susceptible to MIC in industries such as marine engineering and oil exploration.

Waterborne Eco-Sustainable Sol-Gel Coatings Based on Phytic Acid Intercalated Graphene Oxide for Corrosion Protection of Metallic Surfaces.

In the past few years, corrosion protection of metal materials has become a global challenge, due to its great economic importance. For this reason, various methods have been developed to inhibit the corrosion process, such as surface treatment approaches, by employing corrosion inhibitors through the deposition of opportunely designed functional coatings, employed to preserve from corrosion damages metallic substrates. Recently, among these techniques and in order to avoid the toxic chromate-based pre-treatment coatings, silane-based coatings and films loaded with organic and inorganic corrosion inhibitors have been widely used in corrosion mitigation water-based surface treatment. In this study, the synthetic approach was devoted to create an embedded, hosted, waterborne, and eco-friendly matrix, obtained by use of the sol–gel technique, through the reaction of functional alkoxysilane cross-linking precursors, namely (3-glycidyloxypropyl)trimethoxysilane (GPTMS) and (3-aminopropyl)triethoxysilane (APTES), in the presence of graphene oxide (GO) intercalated with natural and non-toxic phytic acid (PA) molecules. As a matter of fact, all experimental results from FT-IR spectroscopy, UV–Vis analysis, and SEM confirmed that PA molecules were successfully decorated on GO. Furthermore, polarization measurements and a neutral salt spray test were used to evaluate the anticorrosive performance on aluminum and steel substrates, thus showing that the GO-PA nanofiller improved the barrier and corrosion protection properties of the developed functional silane-based coatings.

Tannic acid-aminopropyltriethoxysilane co-deposition modified polymer membrane for α-glucosidase immobilization

Mussel-inspired catechol-amine co-deposition is an effective modification strategy for various materials. In this work, polyvinylidene fluoride (PVDF) membrane was employed as the carrier for α-glucosidase immobilization. By virtue of the co-polymerization of tannic acid (TA) and 3-aminopropyltriethoxysilane (APTES) and the hydrolysis of APTES, a hierarchical layer-colloidal nanospheres coating was decorated on the surface of PVDF membrane. Subsequently, α-glucosidase was covalently bound to the modified PVDF membrane through Schiff base reaction and Michael addition reaction between the residual quinine groups in the coating and the amino groups in enzyme molecules. Several parameters affecting the immobilization procedure were investigated thoroughly. The morphology and functional groups of the prepared composite were characterized by scanning electron microscopy (SEM), Fourier transform infrared-Attenuated total reflectance spectroscopy (FTIR-ATR), and X-ray photoelectron spectroscopy (XPS). Combined with capillary electrophoresis (CE) analysis, the performance, enzyme reaction kinetics and inhibition kinetics of PVDF-immobilized α-glucosidase were studied. The immobilized enzyme exhibited the enhanced tolerance to temperature and pH value. In addition, it possessed good reusability maintaining 77.1% of initial relative activity after 11 recycles, and batch-to-batch reproducibility with RSD of 4.3% (n = 10). The Michaelis-Menten constant (Km) of immobilized enzyme was calculated to be 4.16 mM, and IC50 value of acarbose was 0.10 µM. Finally, the PVDF-immobilized α-glucosidase was applied to screening potential inhibitors from 13 kinds of traditional Chinese medicines (TCMs), among which Sanguisorba Radix exhibited the strongest inhibitory activity. The positive results suggested that TA/APTES co-deposition was a simple and mild functionalization method for chemically inert polymer membrane and the proposed screening method was a reliable approach for discovering enzyme inhibitors from TCMs.

Effect of the Coupling Agent (3-Aminopropyl) Triethoxysilane on the Structure and Fire Behavior of Solvent-Free One-Pot Synthesized Silica-Epoxy Nanocomposites.

Uniformly distributed silica/epoxy nanocomposites (2 and 6 wt.% silica content) were obtained through a “solvent-free one-pot” process. The inorganic phases were obtained through “in situ” sol-gel chemistry from two precursors, tetraethyl orthosilicate (TEOS) and (3-aminopropyl)-triethoxysilane (APTES). APTES acts as a coupling agent. Surprisingly when changing TEOS/APTES molar ratio (from 2.32 to 1.25), two opposite trends of glass transformation temperature (Tg) were observed for silica loading, i.e., at lower content, a decreased Tg (for 2 wt.% silica) and at higher content an increased Tg (for 6 wt.% silica) was observed. High-Resolution Transmission Electron Microscopy (HRTEM) showed the formation of multi-sheet silica-based nanoparticles with decreasing size at a lower TEOS/APTES molar ratio. Based on a recently proposed mechanism, the experimental results can be explained by the formation of a co-continuous hybrid network due to reorganization of the epoxy matrix around two different “in situ” sol-gel derived silicatic phases, i.e., micelles formed mainly by APTES and multi-sheet silica nanoparticles. Moreover, the concentration of APTES affected the size distribution of the multi-sheet silica-based nanoparticles, leading to the formation of structures that became smaller at a higher content. Flammability and forced-combustion tests proved that the nanocomposites exhibited excellent fire retardancy.

Anticorrosion properties of silica-based sol-gel coatings on steel – The influence of hydrolysis and condensation conditions

In this paper, we present indirect methods to define the change in the rates of hydrolysis and condensation reactions of a silica oxide network formed of (3-glycidoxypropyl)methyltriethoxysilane (GPTMS) and (3-aminopropyl)triethoxysilane (ApTEOS), which was strongly dependent upon the nature of the solvent used in the reaction environment, such as methanol, ethanol, propanol, butanol and acetone. Electron microscopy (SEM), focused ion beam scanning electron microscopy (FIB), and Raman spectroscopy were used to investigate the morphology and structure changes. UV-VIS spectrometry, a wettability test, a scratch test and electrochemical tests, namely - Tafel's polarization and electrochemical impedance spectroscopy (EIS), were used to analyze the functional changes in the obtained silica coatings. The coating synthesized in a methanol environment showed a polarization resistance (Rp) almost an order of magnitude greater than those synthesized in the other organic solvents. The greatest thickness, nearly 1.5 μm, was obtained with the ethanol-based coatings. Almost twice as much force (near 11 N) was required to detach the acetone-based coatings, compared to the other coatings. Propanol and butanol contribute to the defects created and the decreased protection properties in the final materials and show a statistically significant influence on the formed corrosion film under sol-gel coatings, particularly for coatings based on propanol. No statistically significant influence of the solvents was observed on the thickness of coatings prepared with butanol or acetone.

Optically Transparent Adhesives for Microwave Metamaterial Absorber With PET–PDMS Interface

Bonding of the heterogeneous layers of polymers as a trilayered (or multilayered) transparent metamaterial absorber (MA) is challenging, since the hydrophobic nature of interfacial surfaces does not allow direct bonding. Apart from the mechanical challenges to bond, microwave and optical functionalities of the chosen material need to be studied quantitatively for an optimal choice. Therefore, simulations are performed to study the effect of dielectric constant and thickness of adhesive on the microwave characteristics of polyethylene terephthalate (PET)–polydimethylsiloxane (PDMS)-based microwave MA (MMA). Composites of polyvinyl butyral (PVB) and 3-aminopropyltriethoxy silane (APTES) that address the need for strongly adhesive yet transparent in optical regime and non-interacting in the microwave regime have been developed. Lap-shear tests with plasma-treated PET–PDMS adherends demonstrated to have lap-shear adhesion strengths greater than 0.21 MPa. The optical transmittance of electromagnetic (EM) waves through MA after being adhered with glue is 74.9%. A numerical analysis shows that the proposed microwave absorber absorbs more than 90% of EM waves within the range of 7.97–20.72 GHz after an additional layer of optimal adhesive, which is validated through experiments conducted in anechoic measurements.

Design of a Double Cavity Nanotube Tunnel Field-Effect Transistor-based Biosenser

The manuscript focused on the concept of junction-less tunnel transistor to suggest and simulate the dielectric modulated double cavity nanotube TFET as a biosensor. The proposed biosensor worked as a label-free detector about dielectric constant (K) and charge density (ρ). In this, for neutral biomolecules (streptavidin and 3-aminopropyl-triethoxysilane (APTES)) and charged biomolecule (deoxyribonucleic acid (DNA)) are used for detection by the proposed sensor. The inner and outer cavities of the nanotube biosensor provide a large area for the stabilization of biomolecules and use the benefits of material solubility. The sensing capability of the proposed device investigates various DC performance parameters for the different dielectric biomolecules and charge densities. Further, the effect of substitution of SiO2 gate insulating layer by HfO2 also studies the sensing capability of the proposed biosensor. Moreover, a relative study of the biosensor for the presence and absence of inner and outer nanogap cavities performs in terms of different DC components to analyze the sensitivity variation.

Devising a universal tailored monomer molecular strategy for SiOx/carbon hollow spheres as a synergistic electrocatalyst in azathioprine sensing

Designing hollow spheres (HS) structures of polymer materials with uniformly dispersed SiOx and surface attributes is currently attracting much attention due to their vital roles in catalysis and energy storage applications. Instances of their compilation exist, but such morphological scaffolds require easy yet versatile conceptual approaches. Despite the easy yet controllable assembly of uniformly adorned SiOx and carbon HS (C-HS), producing copious voids simultaneously through a one-step reaction still remains a major challenge. In this study, an ultrafast additive and template-free molecular polymerization strategy were designed to fabricate uniformly dispersed SiOx/C-HS for electrocatalysis. Dual-aldehydes and (3-aminopropyl)triethoxysilane (APTES) were judiciously designed as C and silicon precursors to yield the polymer HS (P-HS) via a simple one-step aldimine condensation. Two different P-HS morphologies were obtained utilizing glyoxal (GL) and glutaraldehyde (GA) as the cross-linkers, proving the great tunability of the methodology. Prominently, in situ carbonization of the P-HS guarantees the uniform integration of SiOx in C-HS at a nanoscale range. As an example of the application of the synthesized P-HS and SiOx/C-HS, the electrochemical performance for azathioprine (AZP) detection was tested. Benefiting from high conductivity, large surface area, and fast electron transfer due to the well-dispersed SiOx in the C-HS substrate surface, the resultant SiOx/C-GA modified electrode showed a low limit of detection (2.26 nM), high sensitivity (4.26 μA μM-1cm-2) and good repeatability and reproducibility for AZP detection. Detection was also validated in actual samples. The strategy adopted, not only implements Si-based C-HS composites as efficient and scalable electrode materials but also paves the way toward a new platform for the synthesis of additive and template-free HS.

Surface-Sensitive Imaging Analysis of Cell-Microenvironment Interactions by Electrochemiluminescence Microscopy.

A complex and heterogeneous cell microenvironment offers not only structural support for cells but also myriad biochemical and biophysical cues. These outside-in signals transmit into cells primarily through integrins, which are the important components of cell-matrix adhesions to direct and maintain cell behaviors and fate. In this work, we report a surface-sensitive imaging methodology for evaluating the difference in cell-matrix adhesions at the single cell level to dissect the impact of the chemical microenvironment on cell behaviors. Cells were cultured on silica nanochannel membrane (SNM) modified indium tin oxide (ITO) electrodes (SNM/ITO) with different terminal surfaces and imaged by electrochemiluminescence microscopy (ECLM). The results show that the surface tethered with Arg-Gly-Asp (RGD) groups can mediate robust cell-microenvironment interaction and those coated with silanol and (3-aminopropyl)triethoxysilane (APTES) groups transmit an intermediate adhesion, while oligo(ethylene glycol) (OEG) coated surface conveys the weakest cell-matrix adhesion. Specific recognition of integrins to different surfaces was further explored in conjunction with selective immunoblocking of different subunits. α6, α5, and α1 integrin subunits were found to recognize SNM, RGD/OEG, and APTES surfaces, respectively. The work provides not only insights into cell-microenvironment interaction but also guideline in the design and development of functional and biomimetic surface materials.

The Potential Application of Starch and Walnut Shells as Biofillers for Natural Rubber (NR) Composites.

The goal of this study was application of corn starch and ground walnut shells in various amounts by weight as biofillers of natural rubber (NR) biocomposites. Additionally, ionic liquid 1-butyl-3-methylimidazolium chloride (BmiCl) and (3-aminopropyl)-triethoxysilane (APTES) were used to increase the activity of biofillers and to improve the curing characteristics of NR composites. The effect of biofillers used and their modification with aminosilane or ionic liquid on the curing characteristics of NR composites and their functional properties, including crosslink density, mechanical properties in static and dynamic conditions, hardness, thermal stability and resistance to thermo-oxidative aging were investigated. Starch and ground walnut shells were classified as inactive fillers, which can be used alternatively to commercial inactive fillers, e.g., chalk. BmiCl and APTES were successfully used to support the vulcanization and to improve the dispersion of biofillers in NR elastomer matrix. Vulcanizates with starch, especially those containing APTES and BmiCl, exhibited improved tensile properties due to the higher crosslink density and homogenous dispersion of starch, which resulted from BmiCl addition. NR filled with ground walnut shells demonstrated improved resistance to thermo-oxidative aging. It resulted from lignin present in walnut shells, the components of which belong to polyphenols, that have an antioxidant activity.