Octadecyltrimethoxysilane Research Articles

Molecule‐level Design to Form Pocket Structures for Improving Amine Efficiency in CO2 Capture

AbstractSolid amine adsorbents represent a promising class of CO2 sorbents, but their amine efficiency is limited by the inaccessibility of peripheral amines. The surface of mesocellular silica foam (MCF) is functionalized with the mixture of short‐chain 3‐Glycidyloxypropyl) triethoxysilane (GPTES) and long‐chain Octadecyltrimethoxysilane (OTMS), forming pocket structures on the support surface, thereby exposing more amine sites and enhancing the amine efficiency of polyethylenimine (PEI). The resulting adsorbent demonstrates a high CO2 adsorption capacity (5.02 mmol g−1 at 50 °C, 10 vol.% CO2, and 50%RH), high amine efficiency (0.43 at the dry condition), outstanding cyclic stability (0.5% performance decline per cycle under the conditions of dry CO2 regeneration), and fast adsorption kinetics (15 min for adsorption saturation at 50 °C). First‐principles calculations and CO2 temperature‐programmed desorption (TPD) experiments demonstrate that the introduction of GPTES and OTMS is beneficial to decreasing adsorption energy and forming paired carbamic acid states and ammonium carbamate states.

Preparation of superhydrophobic coatings with excellent durability by synergistic reinforcement of cationic starch and tannic acid

The intrinsic hydrophilicity of sustainable and environmentally friendly biobased materials like starch and its derivatives limits their potential as hydrophobic functional materials. This study presents an eco-friendly and non-toxic method to create coatings with exceptionally high hydrophobicity. Octadecyltrimethoxysilane (ODS) reacts with nano silica (SiO2) through a silane coupling reaction to form superhydrophobic SiO2. The Si-OH groups generated from ODS hydrolysis can undergo a condensation reaction with tannic acid (TA), which is rich in phenolic hydroxyl groups. This enables the hydrophobic silane to bind indirectly with cationic starch (CS), resulting in a stable superhydrophobic CS-based coating. The coating demonstrates significant hydrophobicity (contact angle >170°), excellent UV light transmittance (<4.05 %), self-cleaning properties, prolonged shelf life (over eight months), antibacterial activity, and encapsulation capability. It also shows a separation efficiency exceeding 99 % after 25 oil-water separation cycles and is easily recoverable. The study elucidates the mechanism behind the preparation process and the factors enhancing hydrophobic properties. The research findings suggest that the novel, cost-effective CS/TA/ODS/SiO2 coating offers a scalable solution for superhydrophobic applications and broadens the horizon for green starch use in hydrophobic materials.

Facile fabrication of ultradurable flame-retardant and hydrophobic cotton fabric with P/N-rich maltodextrin derivative and octadecyltrimethoxysilane

Flame-retardant and hydrophobic cotton fabric provides protections from fire, stain and bacteria in daily life. However, it is still a great challenge to achieve ultrahigh durability via a green and facile technology. Herein, we synthesized a reactive P/N-rich maltodextrin derivative (PM), and reported a facile dipping-baking strategy to fabricate ultradurable flame-retardant and hydrophobic cotton fabric with PM and octadecyltrimethoxysilane (OTMS). The acids released from PM not only reacted with cellulose during baking, but also catalyzed the hydrolysis-polycondensation of OTMS and silylation reaction of cellulose. Thanks to the P/N/Si synergy and the existence of polyalkylsiloxane coating, treated fabric exhibited outstanding flame retardancy and hydrophobicity with a limiting oxygen index (LOI) of 34.7% and a water contact angle (WCA) of 143.3°. The chemical crosslinkings in PM-cellulose and OTMS-cellulose imparted ultrahigh durability to treated fabric. The LOI and WCA of treated fabric still reached 27.2% and 127.9° after 50 harsh washing cycles, respectively. Moreover, the WCA still maintained above 125° after 3000 intense friction cycles or soaked in strongly acidic/alkaline solution for 3 days. This work not only provides a new idea to synthesize biobased reactive flame retardant, but also a feasible and sustainable strategy for fabricating ultradurable hydrophobic and flame-retardant cotton fabric.

Enhanced anti-icing performance of novel superhydrophobic F-L@KH-SiO2/OTMS coating synergistic preparation with bionic micro-nano structures and modified nanoparticles

Surface icing significantly impacts equipment operation and safety in low-temperature environments. Passive de-icing technologies using superhydrophobic materials are gaining attention for their environmental and cost benefits. This study presents a novel superhydrophobic F-L@KH-SiO2/OTMS coating, fabricated through femtosecond laser etching of aluminum alloy to create bionic micro-nano lattice structures. Subsequently, a hydrophobic epoxy coating was sprayed as an adhesive layer, followed by chemical modification of the ablated aluminum alloy surface using 3-(trimethoxysilyl) propyl methacrylate (KH570) modified silicon dioxide (SiO2) nanoparticles, γ-aminopropyltriethoxysilane (KH550), and octadecyltrimethoxysilane (OTMS) as hydrophobizing agents. The resulting coating exhibits excellent superhydrophobic properties, with a contact angle (CA) of 165.92° and a sliding angle (SA) of only 1.25°. The coating demonstrated superior anti-adhesion and bouncing capabilities, effectively preventing droplet freezing and ice formation, which is attributed to the synergistic effect of the modified silica and the cross-linked lattice structure. Compared to other reported superhydrophobic surfaces, this coating showed a longer freezing delay time of 730 s at −20 °C. These findings highlight the potential of the F-L@KH-SiO2/OTMS coating for efficient anti-icing, de-icing, and defrosting applications.

The excellent anti-wear and friction-reducing performance of magnesium silicate hydroxide/graphite nanocomposite (MSH-C) as a lubricant additive

Abstract In this paper, MSH-C and MSH-GO composites were prepared by doping MSH with micron-sized few-layer graphene oxide (∼10 um) and nanoscale graphite (∼300 nm), respectively, during the hydrothermal synthesis process. Octadecyltrimethoxysilane (ODTMS) was used as a surfactant to disperse these two types of additives into the fully formulated oil. Tribological tests demonstrated that MSH-C exhibits much more superior tribological properties when compared to MSH-GO. The findings reveal that the oil sample containing 0.5 wt% MSH-C can effectively reduce wear volume (by approximately 26.4%) as compared to fully formulated oil and that the friction coefficient is decreased to ∼0.02. SEM, Raman, FIB-TEM, and TOF-SIMS characterizations and molecular dynamics simulation were used to investigate the tribological mechanism. A tribo-film composed of two layers of different compositions was formed on the worn surface of MSH-C, indicating the synergistic effect of MSH and graphite.

Superhydrophobic cotton for addressing fatbergs through oily wastewater treatment

Fats, oils and grease (FOGs) deposits in sewers have recently become a significant problem, causing financial strain on water companies, damaging sewer lines, and exposing the environment to dirty water through sanitary sewer overflows. Despite the proactive use of grease traps/interceptors for physical oil-water separation, the issue of FOG deposits persists. This study proposes the use of adsorption-based oil-water separation, employing superhydrophobic cotton, as a new alternative method for removing FOGs. Durable superhydrophobic cotton was successfully prepared using a simple two-step sol-gel method, with octadecyltrimethoxysilane (ODTMS) as a modifying silane. The resulting cotton samples demonstrated remarkable superhydrophobicity, evidenced by water contact angle (WCA) above 154°. Additionally, it exhibited exceptional durability and stability when exposed to hot water, harsh acidic and alkaline solutions, as well as during a laundry test. Moreover, the cotton displayed excellent oil-water separation efficiency (> 98 %) and maintained consistent performance throughout 20 reuse cycles, highlighting its high reusability. This approach holds the potential to address the prevailing FOG deposit issues and contribute to more efficient and sustainable wastewater management practices.

Corrosion inhibition of stainless steel through the formation of hydrophobic nanoporous oxide layer

This study investigates anti-corrosion properties of anodized and hydrophobically modified anodized SUS 304 stainless steel (SS 304). Utilizing electrochemical anodization and subsequent annealing, a well-ordered hexagonally closed-packed nanoporous oxide layer on the SS 304 surface, designated as AAS, was successfully developed. Then, a self-assembled monolayer of silane molecules, namely, octadecyltrimethoxysilane (ODTS) and 1 H,1 H,2 H,2 H-perfluorooctyltriethoxysilane (PFTS), was formed on the nanoporous oxide layer of annealed-anodized SS 304. The FTIR study confirmed the formation of the self-assembly of silane molecules on nanoporous oxide surface. The self-assembled monolayers exhibited hydrophobic surface where hydrophobicity increases with increase of silane molecule concentration and gives a water contact angles measure of 127.60° and ∼ 128.83° for 0.50 wt% ODTS and 0.50 wt% PFTS, respectively. The potentiodynamic polarization study revealed a corrosion rate of 1.485 × 10−3 mm year−1 for AAS, 0.614 × 10−3 mm year−1 for 0.50 wt% ODTS-AAS, and 0.348 × 10−3 mm year−1 for 0.50 wt% PFTS-AAS. This represents a significant reduction in corrosion rate compared to bare stainless steel (4.385 × 10−3 mm year−1) when exposed to a simulated sea water environment. The AAS, 0.50 wt% ODTS-AAS and 0.50 wt% PFTS-AAS exhibited corrosion inhibition efficiency of 66.13 %, 85.97 % and 92.06 %, respectively. Electrochemical impedance analysis revealed that PFTS exhibits roughly double the effective charge transfer resistance of ODTS and 7.4 times higher than that of annealed anodized stainless steel, confirming superior corrosion inhibition capability. Overall, this research illuminates the mechanism behind self-assembled monolayer formation, resulting in the development of hydrophobic surfaces and the inhibition of corrosion on nanoporous oxide layers on stainless steel surfaces.

Bioinspired multifunctional MXene-decorated textile for thermal management, durable self-cleaning, bio-protection and wearable strain sensor

Textile-based wearable electronic devices have gained significant attention due to their promising applications in personal thermal management, human healthcare monitoring, and human motion detection. Herein, a multifunctional MXene-decorated textile has been fabricated as a promising wearable electronic textile for thermal management, durable self-cleaning, bio-protection and wearable strain sensor. In this study, Ti3C2Tx MXene nanosheets, which are followed by surface engineering with mussel-inspired polydopamine coatings and hydrophobic octadecyl trimethoxysilane, are chosen as active materials for constructing multifunctional MXene-decorated textile. Thus, the multifunctional MXene-decorated textile (Cotton@ODMX) is fabricated by spray-coating the hydrophobic MXene-based composites (ODMX) onto the surface of the cotton textile. Such a Cotton@ODMX epitomizes a highly innovative electronic textile that not only retains the flexibility of the original textile, but also possesses remarkable superhydrophobic properties, outstanding photothermal conversion performance, photothermal self-healing capabilities, environmental stability and exceptional photothermal sterilization capabilities. More importantly, Cotton@ODMX is demonstrated to serve as a wearable strain sensor to monitor fundamental human movements, thus highlighting its impressive sensing capabilities. This work offers valuable insights for the development of multifunctional, flexible and wearable electronic devices with promising potential in personal thermal management, human healthcare monitoring, and human motion detection.

Investigation on sacrificial hydrolysis reaction of octadecyltrimethoxysilane for moisture resistance enhancement of metal–organic framework

Imparting water resistance is important for structures which is vulnerable to moisture to maintain the performance. In this study, octadecyltrimethoxysilane (ODTMS), which forms a hydrophobic surface through polymerization on the surface of the material, was used to enhance the hydrophobicity of HKUST-1 (HHK-x). This self-assembled structure reacts as sacrificial barrier to continuously penetrating H2O molecules and this effect is evaluated with detection of O–H peak (3323 cm−1) in FT-IR spectra. The gas adsorption performance is conducted with CO2 gas and the adsorption amount was reduced by 20 % (from 5.77 to 4.62 mmol/g at 25 °C, 1 bar) compared with the pristine HKUST-1 following the trend of specific surface area. However, water adsorption amount was reduced by 50.2 %, which is 2.5 times higher than the decrease in CO2 adsorption capacity. In addition, when the N2 adsorption and cycle adsorption performances were compared after exposing the sample to air for five days, it was confirmed that HHK-40 maintained its microporous structure and stable performance. The manufactured materials exhibited higher durability in a cyclic vapor sorption test depending on the loading amount of ODTMS and exhibits different tendency depending on the rate of humidity. These results experimentally indicate that accessible self-assembly process of ODTMS on water-vulnerable materials to be sustainable and stable in humid air conditions.

Superhydrophobicity wood with reversible photoresponsive property

Superhydrophobic photoresponsive wood (HPW) was synthesized through the vacuum pressure impregnation process with octadecyltrimethoxysilane (OTS), spiropyran, and polyvinyl alcohol (PVA). The process endowed the wood with photostimulation responsiveness and superhydrophobic characteristics. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS), Fourier transform infrared spectroscopy (FTIR), and a contact angle meter were analyzed to determine the micromorphology, chemical composition, and hydrophobicity of the modified wood. The modified wood had a micro-nanometer mastoid structure at the microscopic level, with a large number of hydrophobic groups. The static water contact angle of the modified wood reached 153°, the water absorption rate decreased from 123.28 % to 19.29 %, and the anti-swelling rate was only 1.69 %, showing good hydrophobic and anti-swelling performance. At the same time, color values of the wood L*, a*, b*, and total color difference ΔE*, it was found that spiropyran made the modified wood have a rapid response to light stimulation.

A robust superhydrophobic coating of SER/ ZnO/MWCNTs with high corrosion resistance was prepared by one-step spraying method

Multifunctional integration is the basic feature of artificial superhydrophobic coatings widely used in many fields. This paper presents a simple and economical experimental method to prepare a super hydrophobic coating with super strong corrosion resistance by spraying a mixed solution composed of epoxy resin (EP) as the base, multi-walled carbon nanotubes (MWCNTs), sericite (SER), nano-zinc oxide (ZnO) and octadecyl trimethoxysilane (ODTMS) on an aluminum substrate. Firstly, the superhydrophobic property of the coating prepared in this experiment is better than that of the ordinary coating, and its contact angle reaches 167.3° and rolling angle is as low as 2.7°. Secondly, the superhydrophobic coating can not only maintain the superhydrophobic property in harsh environment (such as: soaking in boiling water for 10 hours, soaking in acid, alkali and salt solution for 7 days, high temperature, burning and strong ultraviolet irradiation, etc.), but also can withstand a variety of mechanical damage without losing the superhydrophobic property (such as: 1000 sandpaper wear cycles, 100 tape stripping cycles and 1000 g grit sustained impact). In addition, the excellent non-wettability of superhydrophobic coating can make it have excellent performance in the field of selfcleaning and anti-fouling. It is worth mentioning that the electrochemical workstation experiment proved that the coating also has good corrosion resistance, and the anticorrosion efficiency reached 99.924%. This strong superhydrophobic coating has many functions, such as self-cleaning, antifouling and corrosion prevention, and will have good application prospects in many fields in the future.

Simple one-pot fabrication of durable superhydrophobic cotton wool using octadecyltrimethoxysilane modified silica-sol for oil-water separation

A fluorine-free superhydrophobic cotton is successfully fabricated using a simple and cost-effective one-pot synthesis method, employing octadecyltrimethoxysilane (ODTMS) as a modifying silane in a silica-sol. Unlike conventional techniques that utilise coupling agents or post-synthesis curing methods to enhance coating stability, this approach eliminates the need for extra chemicals thus saving time and reducing fabrication cost. The prepared cotton demonstrates remarkable superhydrophobicity, as evidenced by a water contact angle of 159°. Additionally, it exhibits exceptional durability and stability when exposed to harsh acidic and alkaline solutions, as well as during laundering test. Moreover, the cotton displays excellent oil–water separation efficiency (>99.0 %) and maintains consistent performance throughout 20 reuse cycles, highlighting its high reusability. Furthermore, the modified cotton is highly effective for separating oil-in-water emulsions, even for highly stable emulsions, achieving separation efficiencies above 90.0 %. The fabrication process is simple and environmentally safe, offering an economical and viable solution for industries handling oily wastewater. Overall, this fluorine-free superhydrophobic cotton presents a promising and cost-effective option for various industrial applications.

Sequestration of oils from water using superhydrophobic silanized montmorillonite-KSF nanoclay coated polyurethane foam

Oil spills have disastrous consequences on the environment. Multifarious absorbents have been applied in oil spill remediation; however, the design of cost-effective, dependable, and environmentally benign absorbents is desirable and pressing. Here, a polyurethane foam (PF) with superhydrophobic/superoleophilic properties was fabricated by surface coating of montmorillonite (MMT) nanoclay. Initially, the hydrophobic MMT was obtained by grafting octadecyltrimethoxysilane (ODTMS) onto the surface of the nanoclay and this was then used to modify the foam via a dip-coating technique. This modification produces a superhydrophobic foam with a water contact angle reaching 153.83 ± 1.86°. The as-prepared foam demonstrates high absorption selectivity and excellent absorption capacity of 29.5–66.5 times weight gain for several organic solvents and oils. The efficiency of separation for multiple oil-water mixtures reached 99.87%. After 10 cycles of absorption-desorption studies, such superhydrophobic foam still sustained good oil absorption performance, thus exhibiting outstanding reusability and desirable regeneration for practical applications. The oil and organic solvent samples could swiftly and continuously be retrieved from the water by the modified foam. The fabrication method for the superhydrophobic PF by its modification with natural clay minerals appears to be simple, economical, and promising for expandable applications in the effective separation of oil-water mixtures.

Octadecyltrimethoxysilane modified freeze-drying magnesium silicate hydroxide towards high-performance wear-resistance: Synthesis, characterization, and tribological evaluation

Magnesium silicate hydroxide (MSH) has attracted much attention as lubricant additive for its environmental-friendly property. However, its hydrophilicity hindered the industrial application in lubricating oils. Here, we used octadecyltrimethoxysilane (ODTMS) to modify freeze-drying magnesium silicate hydroxide (F-MSH) to obtain ODTMS@F-MSH nanomaterial, which functions well in lubricants free of any dispersant. Tribological tests indicate that, compared with a fully formulated oil, the addition of ODTMS@F-MSH reduces wear effectively (∼25.8%). The magnesium, silicon, and oxygen-containing tribo-film formed on the worn surface. The tribo-film forming mechanism was investigated by atomic force microscope (AFM) experiments and Molecular dynamics (MD) simulations. The results indicate that the ODTMS@F-MSH nanoparticles are of much lower stiffness and higher adhesion than ball-milling MSH (B-MSH), thus reducing the possibility of scratching the rubbing surface and promoting nanoparticles’ adsorption on it. Then the solid tribo-film is formed due to sliding contact between moving parts, thereby enhancing the anti-wear performance.

Multifunctional coating on magnesium alloy: Superhydrophobic, self-healing, anti-corrosion and wear-resistant

Superhydrophobic coating (SHC) was fabricated on magnesium (Mg) alloy by sequential surface etching, in-situ growth of MgAl-layered double hydroxides (LDHs), and modification of octadecyl-trimethoxy-silane (OTMS). The so-fabricated SHC possessed high contact angle above 150° and low sliding angle below 10° by using the probe droplet of aqueous solution of HCl (pH = 2), NaOH (pH = 13), NaCl (3.5 wt.%) or others such as milk, cola, and tea. The lubricant behavior as well as wear resistance was enhanced by such a SHC as compared with the bare Mg alloy. Moreover, corrosion of Mg alloy was greatly slowed by such a SHC which maintained long-term hydrophobic property after corrosion immersion in aqueous solution of NaCl for 6 weeks. The scratch on the SHC could be self-healed by immersing into water due to the hydrolytic polycondensation of silane and corrosion decomposition of LDHs within 8 days.

Boosting Red Luminescence of Mn4+ in Tantalum Heptafluoride Based on an Ab Initio-Facilitated Sensitizer and Hydrophobic Surface Modification

A narrow-band red-light component is critical to establish high color rendition and a wide color gamut of phosphor-converted white-light-emitting diodes (pc-WLEDs). In this sense, Mn4+-doped K2SiF6 fluoride is the most successful material that has been commercialized. As with K2SiF6:Mn4+ phosphors, Mn4+-doped tantalum heptafluoride (K2TaF7:Mn4+) fulfills a similar luminescence behavior and has been brought in a promising narrow-band red phosphor. But the limited brightness and low moisture-resistant performances have inevitably blocked its practical application. Herein, we employed the density functional theory (DFT)-based ab initio estimation approach to quickly identify the proper sensitizer by systematically investigating the electronic-band coupling between the several possible sensitizers (Rb, Hf, Zr, Sn, Nb, and Mo) and the luminescent center (Mn). Combined with experimental results, Mo was demonstrated to be the optimal sensitizer, which resulted in a 60% enhancement of the emission. On the side, the moisture sensitivity has been effectively improved via grafting the hydrophobic octadecyltrimethoxysilane (ODTMS) layer on the phosphor surface. Through employing the K2TaF7:Mn4+,Mo6+@ODTMS composite as a red component, warm WLEDs with good performance were achieved with a correlated color temperature (CCT) of 4352 K, a luminous efficacy (LE) of 90.1 lm/W, and a color rendering index (Ra) of 83.4. In addition, a wide color gamut reaching up to 102.8% of the NTSC 1953 value could be realized. Aging tests at 85 °C and 85% humidity for 120 h on this device manifested that the ODTMS-modified phosphor had much better moisture stability than that of the unmodified one. These studies provided viable tools for optimizing Mn4+ luminescence in fluoride hosts.

Preparation and Performance Analysis of a Dimension-Controlled Nano-Drag-Reducing Agent for Low-Permeability Reservoirs

Graphene oxide (GO), as a derivative of graphene, is rich in reactive functional groups on its surface for modification, and the modified graphene oxide (M-GO) has excellent special properties. In this paper, the improved Hummer’s method was used to analyze GO by adjusting the amount of oxidant (potassium permanganate), oxidation time, and temperature, using Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), and laser particle size measurement. The successful synthesis of dimension-controlled GO in the range of 630–1000 nm was confirmed. On this basis, modified graphene oxide (O-M-GO) was prepared by grafting octadecyltrimethoxysilane (OCT). The successful synthesis of O-M-GO was confirmed by FT-IR and XRD. Through a contact angle test, the contact angle of GO before modification was 80 ± 0.5° and that of O-M-GO after modification was 105 ± 0.5°. Combined with SEM analysis, the change in the wettability of O-M-GO was clarified. Core flow test results showed that after O-M-GO was injected into the core, the subsequent brine injection pressure decreased by 14.21%, and the permeability was 1.166 times that before the brine injection. When the injection concentration was 50 mg/L, the drag reduction rate was 14%.

Facile Preparation of a Robust Superhydrophobic SiO2/Epoxy Composite Coating with Favorable Corrosion and Scale Inhibition Performance

Superhydrophobic surfaces with good water repellency are widely studied, but their complex preparation process and poor durability limit their practical application. Herein, a simple and environmentally friendly method to prepare a robust superhydrophobic coating is proposed and its application in the field of corrosion prevention and scale inhibition is explored. Environmentally friendly and low‐cost SiO2 nanoparticles modified by octadecyl trimethoxysilane (ODMS) are mixed with epoxy resin and sprayed onto the surface of metal substrates. The prepared ODMS–SiO2/epoxy resin composite coating has a water contact angle (WCA) of 161.5°, exhibiting excellent superhydrophobicity. In addition, the prepared coating maintains the original microstructure and good superhydrophobicity (WCA is 155°) after 30 cycles of wear test under 200 g load, showing excellent mechanical stability. The inherent superhydrophobic property also endows the coating with excellent corrosion and scale inhibition. The impedance of the composite coating is two orders of magnitude higher than that of the pure epoxy coating. The scaling amount of superhydrophobic composite coating in 24 h is 47% of that of epoxy resin coating. This work provides a new strategy for constructing multifunctional superhydrophobic coatings with excellent mechanical stability, corrosion resistance, and scale inhibition.

Sequential Use of Orthogonal Self‐Assembled Monolayers for Area‐Selective Atomic Layer Deposition of Dielectric on Metal

AbstractAlthough there have been several demonstrations of area‐selective atomic layer deposition (AS‐ALD) of dielectric on dielectric in metal/dielectric patterns, the reverse process of selective dielectric on metal (DoM) is not as well developed due to the challenge of inhibiting only the dielectrics. Unavoidable native oxide formation on metals tends to lead to similar surface chemical properties between metal and dielectric substrates, decreasing the selectivity in inhibitor adsorption. Hence, to achieve DoM, preventing unwanted inhibitor adsorption on metals is critical. This study demonstrates a two‐step strategy of first applying a dodecanethiol (DDT) self‐assembled monolayer (SAM) on a Cu/SiO2 pattern to protect the Cu surfaces from subsequent deposition of an octadecyltrimethoxysilane (OTMS) inhibitor, which then selectively forms an OTMS SAM on SiO2. It is further shown that by removing the DDT protector with thermal treatment before AS‐ALD, subsequent ALD growth on Cu is not affected while ALD remains blocked on the OTMS‐covered SiO2 regions. Using this strategy, DoM is demonstrated with selectivity above 0.9 after 5.6 nm of ZnO and 1.5 nm of Al2O3 ALD. This work presents a new approach to expand the material systems available to AS‐ALD which may help enable more applications in microelectronics, optoelectronics, and energy.

Hydrophobic Magnetite Nanoparticles for Bioseparation: Green Synthesis, Functionalization, and Characterization

In this study, three types of hydrophobized alkyl-modified magnetic nanoparticles (MNPs) comprising direct alkylated-MNPs (A-MNPs), silica-mediated alkyl MNPs (A-SiMNPs), and arginine (Arg)-mediated alkyl MNPs (A-RMNPs) were synthesized successfully. For this purpose, the co-precipitation method was used to synthesize, and octadecyl trimethoxy silane (OTMS) was used as a functionalizing agent. Accordingly, the hydrophobic octadecyl moieties were connected to MNPs. The nanoparticles (NPs) were characterized by XRD, SEM, FTIR, CHN, DLS, and zeta potential analyses. The synthesized coated MNPs represented a decrease in surface charge and magnetization alongside increased surface hydrophobicity and size. It was revealed that the alkylation process was successfully performed to all three MNPs, but A-SiMNPs showed the highest hydrophobicity. Additionally, the novel A-RMNPs, as the most biocompatible type, and A-MNPs showed the highest magnetization among the synthesized MNPs. The results indicate that synthesized NPs can play an important role in bio applications. However, it was revealed that alkyl chains are easily connected to all three MNPs, and that A-MNPs contained the highest alkyl chains and could affect the re-folding and denaturation process of recombinant proteins.