3-aminopropyl Trimethoxysilane Research Articles

Three-dimensional macroscopic aminosilylated nanocellulose aerogels as sustainable bio-adsorbents for the effective removal of heavy metal ions

Designing an environmentally benign bio-adsorbent for the removal of heavy metal ions from aqueous medium was a sustainable strategy to ensure water safety. Herein, three-dimensional macroscopic aminosilyated nanocellulose aerogels (APTMS-modified TO-NFC) for the removal of heavy metal ions in water were successfully synthesized from bamboo-derived TEMPO-oxidized nanofibrillated cellulose (TO-NFC) and aminopropyltrimethoxysilane (APTMs) via a facile freeze-drying process. Owing to a relatively high BET surface area (129.32 m2 g−1), high porosity (99.14%) as well as high substitution degree of amino groups (0.41), the resulting APTMS-modified TO-NFC aerogel exhibited good adsorption capacity of 99.0, 124.5, and 242.1 mg g−1 for Cu2+, Cd2+ and Hg2+, respectively. Furthermore, the crosslinked and three-dimensionally porous architecture imparted it with relatively high compression strength, good excellent stability in water, and ease of recyclability from water after the usage. The pH value of the solution had a great influence on adsorption efficiency of the aerogel adsorbent, and optimal adsorption efficiency could be achieved at pH 3–7. Thermodynamic parameters suggested the spontaneous and endothermic nature of adsorption process. This work provides a facile method for preparing sustainable bio-adsorbent for effective heavy metal ions removal from aqueous medium.

Silver ion loaded 3-aminopropyl trimethoxysilane -modified Fe3O4 nanoparticles for the fabrication of carrageenan-based active packaging films

Fe3O4 nanoparticle loaded with silver ion was prepared as a more efficient, safer, and less environmentally hazardous silver-based antibacterial nanomaterial. The Fe3O4 nanoparticle was modified using 3-aminopropyl trimethoxysilane (APTMS) to enhance the silver ion adsorption capacity and antibacterial activity. Silver ions were adsorbed on pristine Fe3O4 and Fe3O4@NH2 to enhance antibacterial activity. Energy dispersive spectroscopy (EDS) results showed that Fe3O4 adsorbed 2.74 wt% of Ag, whereas Fe3O4@NH2 adsorbed 9.88 wt%. Pristine Fe3O4NP, silver ion loaded Fe3O4 (Fe3O4-Ag), and silver ion loaded Fe3O4@NH2 (Fe3O4@NH2-Ag) were used to manufacture carrageenan-based composite films. Compared with Fe3O4-Ag, Fe3O4@NH2-Ag exhibited stronger antimicrobial activity against E. coli (8.82 vs. 5.02 log reduction) and L. monocytogenes (10.09 vs. 3.93 log reduction). While the addition of Fe3O4 significantly reduced the WCA of the carrageenan films from 61.1 ± 5.4 ° to 37.2 ± 2.1 °, the additions of Fe3O4-Ag and Fe3O4@NH2-Ag reduced the WCA of the film to a lesser extent (56.9 ± 4.6 ° and 56.9 ± 4.6 °, respectively). Fe3O4NP also improved the thermal stability of carrageenan over Fe3O4@NH2-Ag (22 °C vs. 13 °C) and UV blocking properties (T280, 0.1 ± 0.0 % vs. 3.3 ± 1.5 %).

Immobilized protease on magnetic particles for enzymatic protein hydrolysis of poultry by-products

Immobilization of enzymes onto magnetic particles can potentially allow for enzyme reuse, which can significantly reduce the cost associated with e.g. enzymatic protein hydrolysis (EPH) of fish and meat by-products. Here, we report glutaraldehyde-mediated immobilization of a food-grade protease (Subtilisin A) onto magnetic silica particles using three different amine ligands; a short, brush-like linker (aminopropyl trimethoxysilane), a long, flexible linker (Jeffamine), and a gel-like coating (chitosan). The three coupling strategies were evaluated and compared with respect to the amount of immobilized protease, enzyme activity and catalytic performance in the hydrolysis of chicken meat and turkey tendons, respectively. The particle systems showed high reusability (≤85% activity remaining after six consecutive cycles) and storage stability (≤93% activity remaining after 25 months storage). Particle-immobilized enzyme systems were able to catalyze degradation and extraction of protein from chicken meat and turkey tendons.

Structural models and barrier properties of amine-terminated trialkoxysilane monolayers incubated in nonpolar vs. polar protic solvents

The effect of solvent chemistry and polarity on molecular structure and barrier capacity of a resulting trialkoxysilane self-assembled monolayer (SAM) has not yet been well explored. Here, comparative studies of synthesizing (3-aminopropyl)trimethoxysilane (APTMS) SAMs in nonpolar and polar protic solvents, toluene and ethanol, respectively, are made under strictly controlled silanization protocols favoring the growth of orderly SAMs. Atomic force, transmission and scanning electron microscopies suggest that (a) silanization for the two solvents proceeds concurrently from molecule adsorption, admolecule orientation adjustment to the formation of a stably assembled monolayer and (b) both SAMs effectively adsorb 2-nm-sized catalytic particles for electroless Cu deposits to evolve identically in terms of surface coverage. However, bonding structural analysis by angle-resolved X-ray photoelectron spectroscopy suggests that SAM (toluene) has a much higher ordering and closer packing than SAM (ethanol), and is the only qualified barrier for Cu. The effect of solvent's chemistry and polarity on molecular structure and barrier properties of the two SAMs is elucidated by molecular incubation models determined by the relative weighting of bimolecular nucleophilic substitution (SN2) reaction theoretically and uncontrolled molecular oligomerization found experimentally from dynamic light scattering.

Selective upgrading of biomass-derived benzylic ketones by (formic acid)–Pd/HPC–NH2 system with high efficiency under ambient conditions

Selective upgrading of biomass-derived benzylic ketones by (formic acid)–Pd/HPC–NH2 system with high efficiency under ambient conditions

Strengthening the Electromigration Resistance of Nanoscaled Copper Lines by (3-aminopropyl)trimethoxysilane Self-Assembled Monolayer

A nanoscaled copper (Cu) line is subject to aggravated electromigration after prolonged use, and thus the use of ultrathin barrier/capping layer without degrading its electrical properties is increasingly needed. The aim of this study is to investigate the electromigration resistance of Cu interconnect strengthened by a self-assembled monolayer of (3-aminopropyl)trimethoxysilane (APTMS-SAM) and to develop an entirely wet chemically process for the fabrication of Cu lines. The Cu line with its bottom and sidewalls coated by an APTMS-SAM remains intact and yields the lowest resistivity of 1.80 μΩ-cm even after 500 °C annealing. The resistance of the Cu line against electromigration is remarkedly strengthened by using the APTMS-SAM as a molecular thick barrier due to a low relative diffusion rate of atoms under a constant current stressing, leading to an enhancement of thermal stability by at least 100 °C. The depletion of Cu atoms of a bare Cu line is observed to start from its top area, suggesting surface diffusion is the dominating electromigration mechanism. The enhancement of the Cu interconnect encapsulated by an APTMS-SAM is thus proposed, which indeed serves as a barrier to strengthen the electromigration resistance and enhance the thermal stability of the nanoscaled Cu line.

One pot synthesis of luminescent Mn doped ZnSe nanoparticles and its silica based water dispersible formulation for targeted delivery of doxorubicin

The manganese doped zinc selenide nanoparticles (ZnSe:Mn NPs) were synthesized by thermolysis method using oleic acid and oleylamine as a capping agent, 1-octadecene as solvent. Coating of mesoporous silica was done on ZnSe:Mn (ZnSe:Mn@mSilica) which was further functionalized with amine functional groups by treating with (3-aminopropyl)trimethoxysilane. Further pegylation was done to achieve water dispersibility by conjugating carboxyl groups of poly(ethylene glycol) diacid with the amine groups. These pegylated NPs were subsequently treated with ethylenediamine followed by acrylic acid. Conjugation of tris-(hydroxymethyl-aminomethan) was performed by Michael-type addition reaction to afford ZnSe:Mn@mSilica-PEG-Tris-OH. These TRIS functionalized NPs exhibited broad emission ranging from 590-620 nm that is an indicative for their suitability in diagnosis and monitoring progress of cancer treatment. To explore the usefulness of increased surface area because of mesoporosity, doxorubicin was loaded on ZnSe:Mn@mSilica-PEG-Tris-OH NPs through silyl ether linkage and evaluated for cytotoxicity against WEHI-164 mouse fibrosarcoma and RAJI human hematopoietic origin cancer cell lines. A decrease in 12 % of cell viability of WEHI-164 cells while 30% decrease in RAJI cell lines (IC 50 ≈ 45 nM) were observed. This shows that our formulation has more cytotoxic in RAJI cancer cell lines than that of WEHI-164 cancer cells. These results revealed that the formulation has potential for the application in drug delivery and diagnosis in chemotherapeutics.

Aminosilanes grafted nanocrystalline cellulose from oil palm empty fruit bunch aerogel for carbon dioxide capture

The modification of solid adsorbents with aminating agents amid severe climate change has been intensively studied. Previous organic carbon dioxide (CO 2 ) sorbent like nanoporous activated carbon develops micropores but can be easily blocked by organic amine molecules during the impregnation process. Therefore, in this study, aminosilanes with different chain lengths and nitrogen (N) content were used in nanocrystalline cellulose (NCC) modification prior to solid adsorbent aerogel fabrication to investigate their effect on pore formation, surface area, thermal stability, and capacity of CO 2 capture. The NCC derived from oil palm empty fruit bunch fiber (OPEFB) has been modified with 3-(aminopropyl) trimethoxysilane (APTMS), 3-(2-aminoethylamino) propyl-dimethoxymethylsilane (AEAPDMS), and N-(3-trimethoxysilylpropyl) diethylenetriamine (DET3) by grafting method, respectively. Based on the results, aerogel modified with the shortest chain length aminosilane, APTMS-NCC aerogel has a higher CO 2 sorption (0.20 mmol/g adsorbent) than the unmodified NCC aerogel (0.10 mmol/g adsorbent). Meanwhile, the highest surface area properties and thermal stability are demonstrated by NCC grafted by the intermediate chain length aminosilane, AEAPDMS-NCC aerogel. Thus, our work concluded that NCC's modification with low and intermediate chain length and N content aminosilanes prior to aerogel fabrication improved the pore formation, surface area, and CO 2 sorption of the aerogel. The aerogels from aminosilanes functionalized NCC could be developed as a new value-added product in the palm oil industry.

Synthesis and characterization of immobilized glucoamylase on mesocellular foams through spectroscopic techniques and catalytic activity of immobilized enzyme

Siliceous mesocellular foam (MCF) is versatile support material for enzyme immobilization. This material is attractive for its robust, well-defined pore structure with interconnected, ultra large pores that facilitate diffusion. Excellent activity and extremely low level of leaching (metal or enzyme) were attained with these robust supports. MCF was synthesized by hydrothermal procedure using tetraethylorthosilicate (TEOS), amphiphilic block co-polymers Pluronic P123 and Trimethyl benzene as auxilary chemical under acidic conditions. The amino groups have been grafted to as-synthesized mesoporous silica by 3-aminopropyl trimethoxysilane (3-APTS) and glutaraldehyde was then coupled with amino functionalized silica. The physicochemical properties of the prepared materials were characterized by Nitrogen adsorption – desorption, FTIR, XPS, CPMAS NMR techniques. Meso cellular foams having ultra large pore diameter of 241 Å. Results showed that glutaraldehyde bound silica showed highest stability for enzyme binding.

Redox and pH‐Responsive NCC/L‐Cysteine/CM‐β‐CD/FA Contains Disulfide Bond‐Bridged as Nanocarriers for Biosafety and Anti‐Tumor Efficacy System

AbstractIn the present research, a new nanocarrier for targeted drug delivery to tumor cells based on nanocrystalline cellulose (NCC) was synthesized. For this purpose, firstly, the NCC was prepared from microcrystalline cellulose by acidic hydrolysis and then it was modified by aminopropyl trimethoxy silane (APTMS) as a linker. The L‐cysteine was oxidized to form a disulfide bond and conjugated to modify NCC. Afterwards, the disulfide NCC was reacted with carboxymethyl‐β‐cyclodextrin (CM‐β‐CD) and finally, folic acid (FA) as a targeting agent was embedded into the CD cavity via host‐guest interactions for the synthesis of the NCC targeted nanocarrier. Doxorubicin (DOX) was loaded into nanocarrier spheres and the total release of the NCC targeted nanocarrier is about 71% at pH = 5, and about 48% at pH = 7.4 in 45 hours at 37 °C. In the presence of 10 mM DTT, most of the disulfide bonds are broken and the complex nanocarrier is destroyed, thus drug release increases and reaches 83%. The effect of the drugloaded nanocarrier was investigated on breast cancer cells (MCF7 cells). Characterization was performed using Fourier‐transform infrared spectroscopy (FT‐IR), Thermogravimetric analysis (TGA), Proton nuclear magnetic resonance (1H‐NMR), Scanning electron microscope (SEM), Energy dispersive X‐ray (EDX), and Ultraviolet‐visible spectrophotometry (UV‐Vis) analyses.

Preparation and Properties of Novel Superhydrophobic Cellulose Nanofiber Aerogels

The superhydrophobic cellulose nanofiber aerogels were prepared via sol-gel and subsequent freeze-drying with cellulose nanofibers as raw materials and perfluorohexyl ethyl trimethoxysilane and 3-aminopropyl trimethoxysilane as modifying monomers. The effect of volume ratio and total dosage of the two modifying monomers on the superhydrophobic properties was investigated, and the property variations of the cellulose nanofibers before and after modification were also characterized by FT-IR, XRD, TGA, SEM, XPS, and laser flash diffusivity apparatus. The results showed that the modifying monomers were successfully grafted onto cellulose nanofibers, and the prepared modified cellulose nanofiber aerogels had higher thermal stability. After modification, a micron-level arrayed three-dimensional grid superhydrophobic surface structure was constructed, and the surface energy was reduced. The prepared aerogels exhibited superhydrophobicity with a water contact angle up to 151° and excellent thermal insulation performance with a thermal conductivity of 0.035 W·m−1·K−1, which displayed promising application potential in the field of thermal insulation and waterproof materials.

Silver loaded aminosilane modified halloysite for the preparation of carrageenan-based functional films

The surface of the halloysite nanotubes (Hal) was modified to improve the silver ion loading capacity using (3-aminopropyl)trimethoxysilane (APTMS). Surface modification of Hal was confirmed using Fourier transform infrared (FT-IR) spectroscopy and thermal gravimetric analysis (TGA). The modification of Hal using APTMS improved the silver ion adsorption capacity. The functionalized Hal was used as a nanofiller to make the carrageenan-based composite film. The carrageenan-based films with silver ion loaded APTMS-modified halloysite exhibited increased WCA, UV-light barrier, WVP, and antibacterial activity than their unmodified counterparts. The developed film with superior physical and functional properties is likely to be used for active food packaging applications.

Development of room temperature synthesized and functionalized metal-organic framework/graphene oxide composite and pollutant adsorption ability

To improve and develop green adsorbent with high pollutant removal ability to produce clean water from wastewater, the surface of nanocomposite (zeolitic imidazolate framework (ZIF-8) as a metal-organic framework (MOF) with graphene oxide (GO) hybrid) was functionalized using 3-aminopropyl trimethoxy silane (APTMS). To identify and characterization the synthesized materials (ZIF-8, GO, ZG (ZIF-8/GO), and ZGA (ZIF-8/GO/APTMS)), Raman, FTIR, XRD, TGA and TEM analyzes were performed. Acid blue 92 (Ab92) dye was used as a contaminant to remove from the aqueous environment. Effective parameters on the adsorption process, such as the effect of contaminant concentration, dosage, contact time, and pH, were investigated. The results showed that Ab92 removal confirms the Langmuir isotherm and the pseudo-second-order kinetic. The maximum adsorption capacity for Ab92 dye was 371.8 mg/g. According to the results, ZGA nanocomposite is an acceptable adsorbent for removing Ab92 dye from the effluent.

Luminescent water dispersible core-shell – (Y/Eu/Li)VO4@APTES@Folate and (Y/Eu/Li)VO4@Fe3O4@PEG nanocomposites: Biocompatibility and induction heating within the threshold alternating magnetic field

Luminescent red-emitting water dispersible core-shell nanocomposites have been synthesized from luminescent (Y/Eu/Li)VO4 and superparamagnetic Fe3O4 nanoparticles. The conjugation of folic acid on the luminescent (Y/Eu/Li)VO4 nanoparticles was achieved by a simpler chemistry via aminopropyl trimethoxysilane (APTES) coating followed by direct conjugation chemistry using dimethylaminopyridine as acyl transfer agent and N,N-disuccinimidyl carbonate as the protecting group in dimethysulfoxide solvent. On the other hand, polyethyleneglycol coated magnetic-luminescent (Y/Eu/Li)VO4@Fe3O4@PEG nanocomposite was also fabricated from the luminescent (Y/Eu/Li)VO4 and superparamagnetic Fe3O4 nanoparticles. The induction heating abilities of the magnetic-luminescent (Y/Eu/Li)VO4@Fe3O4@PEG nanocomposite have been studied within the threshold alternating magnetic field. The alternating magnetic field (Hf) strengths used in the study ranges from 2.15 × 106 to 4.58 × 106 kAm−1 s−1 which are well below the clinical threshold limit of 5 × 106 kAm−1 s−1 for human body. The nanocomposites exhibited good stability of the dispersion and in vitro biocompatibility towards HeLa cell lines. The median lethal dose, LD50 values are found to be 717.90 μg/mL and 677.00 μg/mL for the (Y/Eu/Li)VO4@[email protected] and (Y/Eu/Li)VO4@Fe3O4@PEG nanocomposites respectively. The synthetic methodology may be adopted for the synthesis of functionalized upconversion phosphors in non-invasive infrared assisted bioimaging and magneto-optically guided cancer hyperthermia.

Non-fluorinated sprayable fabric finish for durable and comfortable superhydrophobic textiles

A non-fluorinated and facile treatment was developed for fabricating durable yet comfortable superhydrophobic textiles. The surface treatment consisted of two sequential sprays: Spray 1, colloidally stable silica nanoparticles synthesized via a sol-gel method, and Spray 2, an optimized combination of reactive polydimethylsiloxane and a long-chain alkyl silane. DLVO theory was applied to evaluate the colloidal stability of the silica nanoparticles and indicated that nanoparticles with the average particle size of 214 nm dispersed in a 75/25 v/v ethanol/water mixture can be further stabilized by extracting the ammonia catalyst. The response surface method (RSM) was utilized to optimize the composition of Spray 2. A water contact angle of 157° was achieved and remained up to 140° after 15 washing cycles. 3-aminopropyl trimethoxysilane (APS) was used to improve the abrasion resistance. Pretreatment using a 1 w/v % solution of APS in ethanol maintained a 5° higher water contact angle after 1,000 Martindale abrasion cycles, compared to the superhydrophobic textile without pretreatment. The air permeability of the treated textiles was 26.4 mL/s.5cm2 and the bending length and crease recovery were statistically unchanged, demonstrating a durable water-repellent fabric finish that maintains physical comfort properties.

Biodegradation and biodetoxification of batik dye wastewater by laccase from Trametes hirsuta EDN 082 immobilised on light expanded clay aggregate.

The online version contains supplementary material available at 10.1007/s13205-021-02806-8.

Effect of Aminosilane Coupling Agent-Modified Nano-SiO2 Particles on Thermodynamic Properties of Epoxy Resin Composites

From the perspective of improving the thermodynamic properties of epoxy resin, it has become the focus of research to enhance the operational stability of GIS (Gas Insulated Substation) basin insulators for UHV (Ultra-High Voltage) equipment. In this paper, three aminosilane coupling agents with different chain lengths, (3-Aminopropyl)trimethoxysilane (KH550), Aminoethyl)-γ-aminopropyltrimethoxysilane (KH792) and 3-[2-(2-Aminoethylamino)ethylamino]propyl-trimethoxysilane (TAPS), were used to modify nano-SiO2 and doped into epoxy resin, respectively, using a combination of experimental and molecular dynamics simulations. The experimental results showed that the surface-grafted KH792 model of nano-SiO2 exhibited the most significant improvement in thermal properties compared with the undoped nanoparticle model. The storage modulus increased by 276 MPa and the Tg increased by 61 K. The simulation results also showed that the mechanical properties of the nano-SiO2 surface-grafted KH792 model were about 3 times higher than that of the undoped nanoparticle model, the Tg increased by 36.5 K, and the thermal conductivity increased by 24.5%.

A study on the anticorrosion performance of epoxy nanocomposite coatings containing epoxy-silane treated nanoclay on mild steel in chloride environment

The halloysite nanoclay was chemically modified with different silanes such as 3-glycidoxypropyl trimethoxysilane (GPTMS) and 3-aminopropyl trimethoxysilane (APTMS) and examined by FTIR, TGA, and XRD techniques. The incorporation of functionalized nanoclay in the epoxy resin enhances the protectant properties of the coated steel. The anticorrosion properties were investigated by electrochemical measurements in chloride environment. The mild steel coated by epoxy-APTMS/clay nanocomposite displayed higher coating resistance (Rc = 5407.88 kΩ cm2) in comparision with pure epoxy coating (Rc = 549.51 kΩ cm2).The mechanical properties (hardness, adhesion strength and tensile strength) of the resultant nanocomposite were also evaluated. The introduction APTMS/clay (4 wt%) to the epoxy coating helps to increase the tensile strength to 80 MPa which is 25% higher than pure epoxy coating. The surface topographies of the studied coatings were investigated by SEM/EDX analysis. The results from electrochemical and mechanical investigations indicated that the as synthesized coatings consisting of epoxy-silanes/clay possessed an excellent adhesion, microhardness and corrosion protection properties.

Synthesis and surface-functionalizing of ordered mesoporous carbon CMK-3 for removal of nitrate from aqueous solution as an effective adsorbent

In this study, the adsorption of nitrate onto ordered mesoporous carbon CMK-3 was investigated. First, CMK-3 was synthesized and then directly amino-functionalized by 3-aminopropyl trimethoxysilane (APTMS). The physicochemical properties of as-prepared adsorbent were characterized by XRD, EDS-SEM, FT-IR and N2 adsorption-desorption. Ultraviolet/visible spectroscopy was used to evaluate the adsorbent ability for nitrate reduction. In batch experiments, the influence of effective parameters such as contact time, adsorbent dosage, solution pH, initial concentration and temperature was investigated on the nitrate adsorption capacity. The obtained results indicated 100% removal efficiency for initial nitrate concentration of 50 mg l−1 and 78% for the concentration of 100 mg l−1, at low adsorbent dosage (3 g l−1) and very fast equilibrium attainment (5 min) without pH dependency (in the range of 2.0–8.0). The maximum nitrate adsorption capacity of Amino-CMK-3 was 48.78 mg g−1 in the concentration range of 50–250 mg g−1. Kinetic studies confirmed that the process followed a pseudo-second-order and that the Langmuir isotherm best fitted the equilibrium adsorption of nitrate. Nitrate desorption occurred after a reasonable time (3 h) and confirmed the adsorbent reusability without further treatment. The higher adsorption capacity of CMK-3 stemmed from its incredible mesoporous structure, including nano-channels that were completely functionalized by amino groups. Grafting aminopropyl groups potentially turned the CMK-3 to a promising adsorbent for nitrate removal.

Synthesis and characterization of poly(L‐lactide)‐block‐poly(ε‐caprolactone)‐grafted titanium dioxide nanoparticles via ring‐opening in situ grafting polymerization

AbstractThe synthesis of nanocomposites via in situ grafting polymerization due to its ability to produce polymeric materials with promising microscopic and macroscopic characteristics is becoming very attractive. In this paper, different poly(L‐Lactide)‐block‐poly(ε‐caprolactone) (PLLA‐b‐PCL) copolymers were in situ synthesized in the presence of modified titanium dioxide (TiO2) nanoparticles (mTNP) as the initiator and stannous octoate as the catalyst. The surface of TiO2 was modified by grafting aminopropyl trimethoxy silane to improve initiator efficiency. Copolymers with 90/10, 70/30, and 50/50 mass ratio of L‐lactide/ ε‐caprolactone and 5 wt% of mTNP (proportional to ε‐caprolactone) were synthesized. The samples were characterized by HNMR, CNMR, FTIR, GPC, TGA, TEM, and DSC, confirming the successful formation of PLLA‐b‐PCL on the surface of mTNP. Tensile test results showed the synthesized nanocomposite with mass ratio of LLA/CL = 70/30 had optimum mechanical properties among other nanocomposites and also in comparison with the neat PLA.