And 3-aminopropyltriethoxysilane Research Articles

Annealing Ti3C2Tz MXenes to Control Surface Chemistry and Friction.

Although surface terminations (such as ═O, -Cl, -F, and -OH) on MXene nanosheets strongly influence their functional properties, synthesis of MXenes with desired types and distribution of those terminations is still challenging. Here, it is demonstrated that thermal annealing helps in removing much of the terminal groups of molten salt-etched multilayered (ML) Ti3C2Tz. In this study, the chloride terminations of molten salt-etched ML-Ti3C2Tz were removed via thermal annealing at increased temperatures under an inert (argon) atmosphere. This thermal annealing created some bare sites available for further functionalization of Ti3C2Tz. XRD, EDS, and XPS measurements confirm the removal of much of the terminal groups of ML-Ti3C2Tz. Here, the annealed ML-Ti3C2Tz was refunctionalized by -OH groups and 3-aminopropyl triethoxysilane (APTES), which was confirmed by FTIR. The -OH and APTES surface-modified ML-Ti3C2Tz are evaluated as a solid lubricant, exhibiting ∼70.1 and 66.7% reduction in friction compared to a steel substrate, respectively. This enhanced performance is attributed to the improved interaction or adhesion of functionalized ML-Ti3C2Tz with the substrate material. This approach allows for the effective surface modification of MXenes and control of their functional properties.

Enhanced thermomechanical properties of epoxy-multiwalled CNT nano-composites.

Viscoelastic properties of thermo-set composites using an epoxy matrix reinforced with pristine CNT and silane-modified MWCNT at different concentrations (0%, 1%, 2% and 4%) were studied to observe the enhanced thermal and mechanical properties supplemented by the increased interfacial interaction due to CNT modification. The composite with pristine CNT was labeled as EPB-CNT, whereas that with silane-modified carbon nanotubes (CNTs) was referred to as ECB-CNT. The silanes used were glycidyloxypropyltrimethoxysilane (GPTS) and 3-aminopropyltriethoxysilane (APTES). Diglycidyl ether of bisphenol-A (DGEBA) was completely cured by Jeffamine D-400 to prepare EJ-0. The amine groups of the 3-aminopropyltriethoxysilane (APTS) partially cured the diglycidyl ether of bisphenol-A (DGEBA) in EAJ-0 by a sequential polymerization process, while the methoxy groups subsequently produced a silica network through the sol-gel method. Subsequently, Jeffamine D-400 was used as a curing agent at elevated temperatures for cross-linking and complete curing. EJ-0 and EAJ-0 were considered as neat films of EPB-CNT and ECB-CNT composites, respectively. Tensile and storage modulus tests, thermal property analysis using TGA, and microstructure characterization using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and TEM were all part of the study. Comparing composites with varying percentages and with neat films, the chemically bonded epoxy-silanized MWCNTs (ECB-CNTs) showed improved performance. ECB-CNT 4% had the highest tensile and storage modulus as well as improved thermal stability. Improved filler material distribution and fewer voids were found through microstructure analysis, strengthening the link between the reinforcement and matrix. The results underscore the potential applications of the CNT-enhanced nanocomposites in the engineering fields of automotive, aerospace, radar-absorbing materials and others. This marks a significant development in the field of composite technology to produce durable and effective materials.

Ambipolarity Sensitivity Investigation using a Charge-Plasma TFET with Graphene Channel for Biomolecule Detection

This research proposes a label-free detection of neutral and charged biomolecules using a graphene channel-based charge-plasma tunnel field effect transistor (GC-CPTFET). The presence of a graphene channel provides a greater tunneling barrier at the channel/drain interface, significantly reducing ambipolarity and increasing the current gradient in the ambipolar condition. A nanocavity is created underneath the drain metal to investigate the sensitivity. Here, the various analog sensitivity parameters of the suggested biosensor are evaluated for a few neutral biomolecules in the ambipolar condition, including gelatin, biotin, and 3-aminopropyl-triethoxysilane (APTES). The sensor’s electrostatic performance, including its IDS-VGS characteristics, energy band, and tunneling distance, has been estimated in the ambipolar state. The sensitivity analysis is carried out in terms of ambipolar sensitivity (SAMB), transconductance (Sgm), cut-off frequency sensitivity (Sft), and maximum frequency sensitivity (Sfm). Further research has been done to study the effects of Deoxyribonucleic Acid (DNA), a charged biomolecule (k = 6) with varied positive and negative charge densities, on various sensitivity parameters. The detailed simulation work for the designed biosensor is achieved using the 2D Silvaco ATLAS device simulation tool.

Eco-friendly phosphorus-free flame-retardant coating for microfiber synthetic leather via alginate-based layer-by-layer technology

The excellent comprehensive properties of microfiber synthetic leathers have led to their wide application in various aspects of our lives. However, the issue of flammability remains a significant challenge that needs to be addressed. Nowadays, the bio-based chemicals used in the flame-retardant materials have extremely grabbed our eyes. Herein, we developed an ecologically friendly flame-retardant microfiber synthetic leather using phosphorus-free layer-by-layer assembly technology (LBL) based on natural polysaccharide alginate (SA) coupled with polyethyleneimine (PEI) and 3-aminopropyltriethoxysilane (APTES). The effect of different LBL coating systems on the flame retardancy of microfiber synthetic leather was investigated. The results demonstrated that the introduction of APTES can completely inhibit the melt-dripping by enhancing char formation through silica elements. Furthermore, the trinary coating system consisting of SA/APTES/PEI exhibited excellent flame retardancy by combining gas-phase action from PEI and condensed-phase function from APTES. This modified microfiber synthetic leather showed a significantly higher limiting oxygen index (LOI) value of 33.0 % with no molten droplet. Additionally, the SA-based coating slightly suppressed the heat release, resulting in a 20 % reduction in total heat release during the combustion test. Overall, this work presents a facile and environmentally-friendly approach for achieving flame-retardant and anti-dripping microfiber synthetic leather.

Multi-functionalized MCNs effectively improve the interfacial compatibility of mixed matrix membranes and enhance CO2 separation performance

Traditional two-dimensional (2D) membrane fillers are prone to interfacial defects such as agglomeration and phase separation in the membrane, limiting the separation performance of membrane. In this paper, microporous carbon nanoplates (MCNs) with controllable microporous structures were functionalized with two different amine carriers of low molecular weight polyethyleneimine (PEI) and 3-aminopropyl triethoxysilane (APTES) to prepare multi-functionalized microporous carbon nanoplates (MfMCNs). It is worth noting that with the success of composite functionalization, the filling content of mixed matrix membranes is also high to a certain extent. To a certain extent, it has been demonstrated that interfacial compatibility between the polymer and the fillers has been improved. It was confirmed by characterization technology that the morphology of the fillers had not been changed, but the pore size of MfMCNs was declined to 0.53–0.55 nm because part of the amino carrier was immersed in the pore structure of MfMCNs. The gas permeability tests under dry gas and wet gas conditions show that the improvement of phase interface by MfMCNs is significant. Under the condition of a dry gas test, the CO2/N2 selectivity of MfMCNs/Pebax-1.0 wt% MMMs is 76.3, which is 27 % higher than that of MCNs/Pebax-1.0 wt% MMMs. Under the moisture condition, the permeability and selectivity of MfMCNs/Pebax-1.0 wt% MMMs CO2 are 287.72 Barrer and 79.1 separately. Compared with Pebax membrane, the permeability of CO2 (176.6 Barrer) was rose by 62.9 %, and the selectivity of CO2 (59.1) was rose by 33.84 %. Significantly, the best MMMs separation performance exceeds upper limit of Robeson. This provides a powerful strategy to strengthen the compatibility between inorganic materials and polymers and strengthen the performance of MMMs in CO2 gas capture.

Intermolecular Interactions in 3-Aminopropyltrimethoxysilane, N-Methyl-3-aminopropyltrimethoxysilane and 3-Aminopropyltriethoxysilane: Insights from Computational Spectroscopy

In this work, a computational spectroscopy approach was used to provide a complete assignment of the inelastic neutron scattering spectra of three title alkoxysilane derivatives—3-aminopropyltrimethoxysilane (APTS), N-methyl-3-aminopropyltrimethoxysilane (MAPTS), and 3-aminopropyltriethoxysilane (APTES). The simulated spectra obtained from density functional theory (DFT) calculations exhibit a remarkable match with the experimental spectra. The description of the experimental band profiles improves as the number of molecules considered in the theoretical model increases, from monomers to trimers. This highlights the significance of incorporating non-covalent interactions, encompassing classical NH···N, N–H···O, as well as C–H···N and C–H···O hydrogen bond contacts, to achieve a comprehensive understanding of the system. A distinct scenario emerges when considering optical vibrational techniques, infrared and Raman spectroscopy. In these instances, the monomer model provides a reasonable description of the experimental spectra, and no substantial alterations are observed in the simulated spectra when employing dimer and trimer models. This observation underscores the distinctive ability of neutron spectroscopy in combination with DFT calculations in assessing the structure and dynamics of molecular materials.

Synergistic Passivation Inducing Long‐Term Stability for Fluorescent CsPbI3 Perovskite Nanocrystals

AbstractCesium lead halide perovskite nanocrystals (PNCs) are promising candidates for photoelectric applications due to their remarkable optoelectronic properties. However, the poor stability of PNCs, especially oleic acid (OA)/oleylamine (OAm)‐capped CsPbI3, is the main obstacle to their commercialization. In this study, CsPbI3 PNCs with long‐term stability are prepared through synergistic passivation of n‐octylphosphonic acid (OPA) and (3‐aminopropyl) triethoxysilane (APS). OPA provides a stronger binding affinity to passivate surface defects, while the SiO2 layer formed by APS can further reduce ligand detachment and block the access of external factors to the PNCs. The stability of OPA/APS‐capped CsPbI3 PNCs can be synergistically enhanced in comparison with that of OA/OAm‐capped PNCs, the fluorescence of which can be also increased significantly. Employing the high‐performance OPA/APS‐capped CsPbI3 PNCs as color‐converting materials, a white light‐emitting diode with a color coordinate of (0.33 and 0.32) and a wide color gamut of 126% National Television Standard Committee color space is fabricated.

One-step, low-cost and environmentally friendly method to prepare superhydrophilic polyester fabric for oil-water separation

Polyester (PET) fabric is currently the world's most produced and widely used synthetic fiber due to its excellent mechanical properties, thermal stability and corrosion resistance. However, the poor hydrophilicity and hygroscopicity of PET fabric limit its application. In this paper, based on tannic acid (TA) and 3-aminopropyltriethoxysilane (APTES), a simple and efficient one-step method was used to construct TA-APTES nanoparticle coating on the surface of PET fabric to obtain superhydrophilicity. The surface morphology, microstructure and coating durability of the modified PET fabric were investigated. The results showed that under the optimal reaction conditions, the water contact angle (CA) of the modified fabric surface was 0°, which remained superhydrophilic after 800 times of rubbing or 20 times of washing. The modified PET fabric exhibited exceptional breathability, dyeing properties, and ultraviolet (UV) resistance, suggesting its high potential in the apparel industry. It could separate the oil-water mixture with high separation efficiency (98.98 %) and water flux (6705.53 L·m−2·h−1). The separation efficiency (97.64 %) and water flux (5968.45 L·m−2·h−1) for separating oil-in-water emulsions were satisfactory. Moreover, the modified PET fabric exhibited excellent chemical stability and can perform efficiently in harsh environment.

Amino-Functionalized Silica@Resorcinol-Formaldehyde Nanocomposites for the Removal of Cr(VI) from Aqueous Solutions.

Amino-functionalized silica@resorcinol-formaldehyde nanocomposites (NH2-SiO2@RF) were synthesized for the removal of Cr(VI) from aqueous solutions using the sol-gel technique with two simple preparation steps, including the one-pot synthesis of SiO2@RF using the Stöber method and (3-aminopropyl)triethoxysilane (APTES) modification. The morphology, particle size, functional group, and thermal stability of the obtained nanocomposites were systematically characterized, with the results indicating a uniform sphericity with a particle size of 200 nm and high thermal stability. The adsorption results demonstrated that the preferred pH value was 2, and the data were well fitted with the Langmuir and Temkin isotherm models and quasi-second-order kinetic equation, indicating a high adsorption capacity. The maximum Cr(VI) adsorption capacity from the nonlinear form of the Langmuir model was 272.6 mg·g-1. The intra-particle diffusion model accurately described the adsorption of Cr(VI) onto NH2-SiO2@RF. The changes in Gibb's free energy, enthalpy, and entropy revealed that Cr(VI) adsorption onto NH2-SiO2@RF was a spontaneous and endothermic process. Furthermore, high selectivity was demonstrated in the material for the removal of Cr(VI) from commonly coexisting ions. The obtained nanocomposites had good regeneration properties and maintained a removal rate above 85% in the fifth adsorption-desorption experiments. Moreover, under the optimized adsorption conditions, the obtained nanocomposites were preliminarily applied to tannery wastewater, demonstrating an excellent removal effect, which indicates their potential application value.

Efficient removal of fluoride ion by the composite forward osmosis membrane with modified cellulose nanocrystal interlayer

In this paper, the performance of three-layer film composite (TFC) forward osmosis (FO) membrane for the retention of fluoride ions was investigated. A cellulose nanocrystal (CNC) interlayer was introduced on the porous substrate by coating method to enhance the hydrophilicity and retention capacity of the FO membrane. In order to improve the dispersibility of CNC, boric acid (BA) and (3-aminopropyl)triethoxysilane (APTES) were used for chemical modification, respectively. The characterization results demonstrated the successful introduction of CNC, BA/CNC and APTES/CNC–CNC interlayers. The introduction of the interlayer enhanced the hydrophilicity of the membrane and increased the negative surface charge, which facilitated the transport of water molecules and the retention of fluoride ions. The FO tests indicated that the water flux of TFC/CNC membrane was increased by 46.4% compared to the original TFC membrane, and the water flux of TFC/APTES-CNC and TFC/BA-CNC membranes were higher than that of TFC/CNC membranes by 5.9% and 13.0%, respectively. 97.0% and 97.6% of the fluoride ions of TFC/BA-CNC and TFC/APTES-CNC could be retained. Based on the molecular simulation of adsorption, it was demonstrated that BA-CNC interlayer was more favorable for the adsorption of water molecules than CNC and APTES-CNC interlayer. This study contributes to the development of high-performance TFC-FO membrane for the treatment of wastewater containing fluoride.

A new SERS quantitative analysis method for trace malathion with recognition and catalytic amplification difunctional MOFTb@Au@MIP nanoprobe

New multifunctional nanomaterial preparation and its application to trace pollutant analysis are interesting to peoples. Using terbium metal-organic framework loaded gold nanoparticles (MOFTb@Au) as the nanosubstrate and 3-aminopropyltriethoxysilane (APTES) as the functional monomer, a new bifunctional nanosurface molecularly imprinted polymer nanoprobe of MOFTb@Au@MIP with strongly recognition and catalytic amplification functions was prepared by the microwave sol-gel procedure. It was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier infrared spectroscopy (FTIR) and other techniques. The nanoprobe was found to specifically recognize malathion (MAL) and catalyze the L-cysteine (Cys)-HAuCl4 nanogold indicator reaction to amplify the molecular spectral signal. The gold nanoparticles (AuNPs) generated in the system show a strong surface-enhanced Raman scattering (SERS) effect, resonant Rayleigh scattering (RRS) peak and UV absorption (Abs) peak at 1615 cm−1, 370 nm and 520 nm, respectively. Based on this, a new SERS/RRS/Abs trimode method for the detection of MAL can be established. It has been applied to the analysis of cereal samples with satisfactory recoveries of 95.2–107.4% and precision of 3.76–9.06%.

Nanocomposites of poly(butylene adipate‐co‐terephthalate) containing sepiolite modified with 3‐aminopropyltriethoxysilane and octadecyl isocyanate

AbstractThe properties of nanocomposites are directly affected by the filler–matrix interaction and therefore surface filler modification is often necessary to improve the mechanical properties of nanocomposites. Our study evaluated surface modification of sepiolite (SEP) on properties of poly(butylene adipate‐co‐terephthalate) (PBAT)‐based nanocomposites. The nanofillers were modified using two organic modifiers, octadecyl isocyanate (OI), and 3‐aminopropyltriethoxysilane (APTES). OI showed higher treatment efficiency than APTES and better results in alkyl groups on the surface of the nanofiller, with crystalline profile, which remained in the nanocomposites. The effect of organo‐sepiolites on the properties of PBAT nanocomposites was investigated by DSC, XRD, TGA, FTIR, scanning electron microscopy (SEM), and mechanical tensile tests. TGA analysis showed that the addition of O‐SEP on PBAT decreases its thermal stability. SEM analysis showed cavities and fiber tips in the matrix associated with clay agglomerates and some untreated clay faces, which impair filler‐matrix interfacial adhesion. Both treatments increased the elastic modulus and preserved the elongation and tensile strength of PBAT and the treatment with OI results in a higher modulus. Although some studies to improve the clay dispersion are necessary, the promising results reveal the potential of using OI and APTES as SEP modifiers to reinforce PBAT or other polyesters.

Synthesis and modification of MIL-101-NH2-based metal organic frameworks for preparation of SPME fibers using sol-gel methodology

Implementation of metal-organic frameworks (MOFs) in the separation science is attractive for many researchers, nowadays. In this study, three MOFs were synthesized and employed as extractive coating fibers. The MIL-101-NH2-based coatings were implemented in immersed solid phase microextraction (ISPME) of organophosphorus pesticides (OPPs) from real-life samples. The three different kinds of fiber coatings included MIL-101-NH2 and its acyl and ethyl modified structures as particles and 3-aminopropyl triethoxysilane (APTES) sol-gel precursor as binder. Each single MOF was coated on a stainless steel substrate via sol-gel technique. The uniform and tunable pore structure, high surface area, and capability to functionalization of MIL-101-NH2, make it susceptible for isolation of a wide range of analytes from small to large molecules. Extraction performance of the synthesized fiber coatings with different functionalities was examined on some model OPPs, followed by gas chromatography-mass spectrometry (GC–MS). The highest extraction efficiency was achieved by the acyl-modified (MIL-101-NHCOCH3) fiber coating. The effects of various parameters affecting the extraction and desorption efficiency such as desorption time, desorption temperature, ionic strength, stirring rate, extraction time and temperature for the selected fiber were investigated and optimized. All the synthesized fiber coatings showed sufficient affinity while the acyl modified extractive phase was found to be very sensitive for determination of OPPs with reliable figures of merit such as acceptable linear dynamic ranges (1–1000 & 5–1000 ng.kg−1, here two linear dynamic ranges (LDR) are reported due to the variation of LDR ranges from one analyte to another), low limits of detection (0.2–1 ng.kg−1), suitable intra–day (RSD% <13%) and inter–day relative standard deviation (RSD% <15%).

A green, one-step and general engineering platform for high-adhesion superhydrophobic surfaces

The development of simple, low-cost and universal surface modification strategy toward superhydrophobic materials with high adhesion is greatly desired due to its wide applications. Herein, we developed a one-step and general method to achieve the high-adhesion superhydrophobic transformation of various materials by simply depositing the natural urushiol and 3-aminopropyltriethoxysilane (APTES) in ethanol solution. Owing to the self-polymerization of urushiol and the hydrolysis of APTES, a hierarchical structure could be constructed with multi-layered submicron spheres. The resulting urushiol/APTES coating exhibited a water contact angle of 151.2 ± 3° and an adhesive force as high as 142.7 μN with water benefiting from the hierarchical structure and the long alkyl chains of urushiol. As a result, this high-adhesion superhydrophobic surface could easily realize efficient microdroplet manipulation, hemostasis, and oil/water separation. Moreover, the urushiol/APTES coating showed outstanding stability after repeatedly tore with an adhesive tape for 300 times, ultrasonic treated for 300 s, or immersed in strong acidic or alkaline solutions for 24 h. Based on the easy fabrication, high property, and good stability, this surface modification strategy can be a powerful platform to engineer various materials to be high-adhesion superhydrophobic for wide potential applications.

Removal of GenX by APTES functionalized diepoxyoctane cross-linked chitosan beads

Perfluoro-2-propoxypropanoic acid ammonium salt, commonly known as GenX, is a persistent, bioaccumulative, and toxic synthetic organofluorine compound utilized in producing various products. It has become a concern due to its extensive presence in the aquatic environment and its resistance to conventional water treatment methods. This study achieved effective adsorption of GenX by employing chitosan (CS) modified adsorbent. Cross-linked and aminated CS beads were synthesized using 1,2:7,8-diepoxyoctane (DEO) and 3-aminopropyl triethoxysilane (APTES). The prepared CS-DEO-APTES adsorbent exhibited an adsorption capacity of 825.9 mg/g, which was 2.26 times higher than that of CS beads (364.6 mg/g), attributed to its higher content of amino groups. Additionally, the CS-DEO-APTES adsorbent demonstrated excellent stability under acidic conditions (optimal pH= 4) due to the cross-linking process. Kinetic data, following a pseudo-second-order rate and isothermal data, fitting well with the Langmuir model, indicated that the interactions between GenX and CS-DEO-APTES were chemisorptive, with a nearly uniform distribution of adsorption sites. GenX-saturated beads were successfully regenerated for at least 6 cycles using a 1 % w/v aqueous NaCl and methanol solution (30:70 % v/v). Density functional theory (DFT) calculations suggested that electrostatic interactions primarily influence the adsorption of GenX. These results highlight the effectiveness of the CS-DEO-APTES adsorbent as a viable option for removing GenX from aqueous solutions.

A “built-up” composite film with synergistic functionalities on Mg–2Zn–1Mn bioresorbable stents improves corrosion control effects and biocompatibility

Control of premature corrosion of magnesium (Mg) alloy bioresorbable stents (BRS) is frequently achieved by the addition of rare earth elements. However, limited long-term experience with these elements causes concerns for clinical application and alternative methods of corrosion control are sought after. Herein, we report a "built-up" composite film consisting of a bottom layer of MgF2 conversion coating, a sandwich layer of a poly (1, 3-trimethylene carbonate) (PTMC) and 3-aminopropyl triethoxysilane (APTES) co-spray coating (PA) and on top a layer of poly (lactic-co-glycolic acid) (PLGA) ultrasonic spray coating to decorate the rare earth element-free Mg-2Zn-1Mn (ZM21) BRS for tailoring both corrosion resistance and biological functions. The developed "built-up" composite film shows synergistic functionalities, allowing the compression and expansion of the coated ZM21 BRS on an angioplasty balloon without cracking or peeling. Of special importance is that the synergistic corrosion control effects of the "built-up" composite film allow for maintaining the mechanical integrity of stents for up to 3 months, where complete biodegradation and no foreign matter residue were observed about half a year after implantation in rabbit iliac arteries. Moreover, the functionalized ZM21 BRS accomplished re-endothelialization within one month.

Investigation of the catalytic effect of defective Ni-MOF-74 on polymerization of dopamine and multi-pore polydopamine photothermal coating constructed with defective Ni-MOF-74 particles

Photothermal coating is an effective way to convert the seawater into fresh water, which is controlled by the light utilization capacity and micro-channel for the vaporation of water. In order to improve the effect of water evaporation and water purification driven by sunlight, polydopamine (PDA) coating with more micro-channel and high bonding was formed through the introduction of porous material and 3-Aminopropyltriethoxysilane (AMEO). Compared with Ni-MOF-74, defective Ni-MOF-74 could produce more coordination with dopamine and promote the polymerization of dopamine, resulting in the formation of sea cucumber structure, which is foundation for the micro-channel of the deposition coating of PDA. Also, depending on the sea cucumber structure, the as-prepared coating of PES/PDA/MOF-30 mg by the two-solvent strategy possesses the water evaporation rate of 1.85 kg/(m2·h), the photothermal conversion efficiency of 98.4%, the retention rate of alkali metal and heavy metal ions above 99% and good long-term stability. The coating with good comprehensive property is good choice for the water purification.

Water‐Dispersable Silica‐Supported Nanocrystalline Pb‐Free Perovskite Rb7Bi3Cl16@SiO2 for ATP‐Responsive Bio‐Imaging

AbstractLead‐free perovskite nanocrystal has attracted more and more attention due to its low toxicity and highly luminescence, however, its low stability in water and biotoxicity greatly limits its practical application in sensing in aqueous media, especially, biological imaging. Herein, we develop water‐dispersed Bi‐based perovskite nanocrystals (NCs) coated with SiO2, namely, Rb7Bi3Cl16 NCs@SiO2, where Rb7Bi3Cl16 NCs@SiO2 powder could be obtained through a simply mixing Rb7Bi3Cl16 nanocrystals dispersed in toluene and 3‐aminopropyltriethoxysilane (APTES). Comparison with Rb7Bi3Cl16 nanocrystals (NCs), the photoluminescence (PL) spectra of the Rb7Bi3Cl16 NCs@SiO2 dispersed in water is slight red‐shifted to 445 nm; in addition, its PL quantum yield (PLQY) is increased from 28.43 % of Rb7Bi3Cl16 NCs to 37.03 % owing to the surface passivation and coating of SiO2 from the hydrolysis of APTES. Therefore, this water‐stable, highly luminescent and low‐cytotoxic Rb7Bi3Cl16 NCs@SiO2 nanoparticles can be applied to cell imaging. Furthermore, the tannic acid modified Rb7Bi3Cl16 NCs@SiO2 exhibits adenosine‐5′‐triphosphate disodium salt (ATP) response performance, indicating its potential application in bio‐imaging and biomedicine.

Internally bridged nanosilica for loadings and release of sparsely soluble compounds

The engineering of a new monodisperse colloid with a sea urchin-like structure with a large complex internal structure is reported, in which silica surfaces are bridged by an aromatic organic cross-linker to serve as a nanocarrier host for drugs such as doxorubicin (DOX) against breast cancer cells. While dendritic fibrous nanosilica (DFNS) was employed and we do not observe a dendritic structure, these particles are referred to as sea urchin-like nanostructured silica (SNS). Since the structure of SNS consists of many silica fibrils protruding from the core, similar to the hairs of a sea urchin. For the aromatic structured cross-linker, bis(propyliminomethyl)benzene (b(PIM)B-S or silanated terephtaldehyde) were employed, which are prepared with terephtaldehyde and 3-aminopropyltriethoxy-silane (APTES) through a simple Schiff base reaction. b(PIM)B-S bridges were introduced into SNS under open vessel reflux conditions. SPS refers to the product obtained by incorporating the cross-linker b(PIM)B-S in ultra-small colloidal SNS particles. In-situ incorporation of DOX molecules resulted in SPS-DOX. The pH-responsive SPS nanocomposites were tested as biocompatible nanocarriers for controllable doxorubicin (DOX) delivery. We conclude that SPS is a unique colloid which has promising potential for technological applications such as advanced drug delivery systems, wastewater remediation and as a catalyst for green organic reactions in water.

Synthesis and Characterization of Amorphous SiO2−FexOy Materials Starting from Iron Sulfate for Preliminary Studies of CO2 Adsorption

The goal of this work is to investigate the effectiveness of amorphous SiO2−FexOy loaded by functionalization with Ce(SO4)2, Li2SO4, and 3-aminopropyltriethoxysilane (APTES) for CO2 adsorption. Silica and iron-based materials are gaining popularity due to their wide range of applications, such as catalysis, photocatalysis, imaging, etc.; however, there are very few studies regarding the adsorption of CO2 with the aforementioned materials. In our study, we proposed to test their ability in this direction by adding cerium sulfate and lithium sulfate. Three base materials were obtained and characterized using XRD, FTIR, RAMAN, TG, SEM, and BET followed by their functionalization with amino groups by using of the APTES precursor. The SEM images indicate an increase in size, forming clusters from 100 nm for base materials to 500 nm for functionalized materials. The results indicate a maximum CO2 adsorption of 1.58 mmol/g material for the SiO2−FexOy−Li−APTES sample.