Disperser Solvent Research Articles

Edge Functionalization of Bulk γ-Graphyne Facilitates Mechanical Exfoliation and Modulates the Mode of Sheet Stacking.

We have successfully achieved selective and efficient functionalization of sheet edges in microcrystalline multilayer γ-graphyne through two methods: cross-coupling with residual bromide edge groups and copper-catalyzed azide-alkyne cycloaddition (CuAAC) with edge terminal alkyne groups. This modification significantly enhances the ease of mechanical exfoliation and dispersibility of the sheets of γ-graphyne. Specifically, C18-grafted γ-graphyne forms stable dispersions in compatible organic solvents, allowing for the imaging of atomically thin layers of γ-graphyne for the first time. Additionally, we have discovered that phenylacetylide edge groups alter the preferred stacking mode of γ-graphyne sheets. Few-layer flakes of Ph-edge γ-graphyne exhibit a preference for the R3m space group, contrasting with the aperiodic stacking of Br-edge γ-graphyne. These results open the door for scalable exfoliation of few-layer flakes of γ-graphyne with a high aspect ratio, enabling potential applications in carbon electronics.

Modeling order–disorder boundaries of colloidal dispersions in organic solvents using interaction force measurements

HypothesisThe formation of soft colloidal crystals, which are nonclose-packed ordered arrays of colloidal particles suspended in a solvent, is dictated by a single physical factor that yields a fixed threshold at order–disorder boundaries for different experimental conditions such as ion concentration, solvent type, and particle size. Identifying the determinant factor and its threshold value should enable the prediction of the critical concentrations of colloidal particles to form soft colloidal crystals. ExperimentsSoft colloidal crystals were fabricated using a series of monohydric alcohols as dispersion media and reflectance spectra were measured to locate order–disorder boundaries. The interaction forces acting between particles were also measured by employing atomic force microscopy. FindingsThe interparticle forces at the order–disorder boundaries exhibited a universal threshold that was independent of the solvent types including alcohols and water. Therefore, the determinant factor for the formation of soft colloidal crystals was determined to be the force acting between the particles. Furthermore, a priori calculation of this critical force and consequently the critical particle concentration in colloidal systems was demonstrated by referring to the pressure at the liquid-to-solid transition in a hard sphere system (Alder transition).

Dispersive liquid–liquid microextraction based on deep eutectic solvent followed by high-performance liquid chromatography-ultraviolet for imidacloprid, hexythiazox, and fenpyroximate determination: Experimental design approach

Dispersive liquid–liquid microextraction (DLLME) of three insecticides, including imidacloprid (I), hexythiazox (H), and fenpyroximate (F), was performed as an efficient method for separation and preconcentration using a deep eutectic choline chloride-acetic acid solvent (DES) followed by determination by high-performance liquid chromatography-ultraviolet (HPLC-UV). The experimental design approach (central composite design) was used to optimize the effective parameters. According to the results, the addition of salt had no significant effect on extraction among the four parameters studied, including pH, DES volume (dispersive solvent), salt concentration, and chloroform volume. The optimized conditions in the DES-DLLME-HPLC-UV method were pH = 6.00, 100 µL DES, and 138 µL chloroform. Under optimized conditions, a wide linear range of 1.00 × 10−3-20.00 µg mL−1 was obtained for three insecticides. The enhancement factors were 11.22, 58.04, and 39.65 and the limit of detection of 3.00 × 10−4, 2.00 × 10−4, and 2.00 × 10−4 µg mL−1, and the limit of quantification of 9.00 × 10−4, 8.00 × 10−4, and 6.00 × 10−4 µg mL−1 were also determined for imidacloprid, hexythiazox, and fenpyroximate, respectively. The presence of other components including benomyl, dimethoate, mancozeb, captan, thiodicarb, carbendazim, and oxyfluorfen, showed no significant interference effect on the determination of three insecticides up to 50-fold. The method is eco-friendly benign, sensitive, precise, and straightforward as shown by the results.

Graphene-doped silicon-carbon materials with multi-interface structures for lithium-ion battery anodes

The carbon nanomaterials are usually used to improve the electrical conductivity and stability of silicon (Si) anodes for lithium-ion batteries. However, the Si-based composites containing carbon nanomaterials generally show large specific surface area, leading to severe side reactions that generate large amounts of solid electrolyte interphase films. Herein, we embedded graphene oxide (GO) and silicon nanoparticles (Si NPs) uniformly in pitch matrix by solvent dispersion. The internally doped GO reduces the exposed surface and improves the electrical conductivity of the composite. Meanwhile, the multi-interface structures are constructed inside to limit the domains of Si NPs and improve the structural stability of the material. When evaluated as anodes, the Si/graphene/pitch-based carbon composite anode exhibits the outstanding electrochemical properties, delivering a reversible capacity of 820.8 mAh/g at 50 mA g−1, as well as a capacity retention of 93.6 % after 1000 cycles at 2 A/g. In addition, when assembled with the LiFePO4 cathode, the full cell exhibits an impressive capacity retention of 95 % after 100 cycles at 85 mA g−1. This work provides a valuable design concept for the development of Si/carbon anodes.

Improved preconcentration workflow for organic explosive traces in aqueous samples using solvent-assisted dispersive solid-phase extraction

The present study deals with the development of a solvent-assisted dispersive solid phase extraction method for the extraction of HMX, RDX, and TNT from aqueous samples. Benzophenone and methanol were selected as explosives sorbent and dispersive solvent respectively. Extraction parameters like pH, extraction time, amount of sorbent, volume and type of the disperser solvent and centrifuge time were optimized. Dispersion of 0.5 mL dispersive solution (4% (w/v) benzophenone in methanol) was performed by injection into the 5 mL aqueous sample (pH=7) using a 1.0 mL syringe. After centrifuge, the extracted explosives were analyzed by high performance liquid chromatography with ultraviolet detection (HPLC-Uv). The results indicated that the linear ranges with the correlation coefficients of 0.99 ≤ R2 were 1.6–204.6 μg L−1, 1.4–213.7 μg L−1 and 1.3–225.9 μg L−1 for HMX, RDX and TNT respectively. The limit of detection and limit of quantification obtained for each explosive were: 0.3 μg L−1 and 0.8 μg L−1 for HMX, 0.3 μg L−1 and 0.9 μg L−1 for RDX and 0.2 μg L−1 and 0.7 μg L−1 for TNT. Finally, the practical applicability of the developed method was evaluated for the extraction of some organic explosives in water samples followed their determination by HPLC-Uv.

RGO/ANFs composite fibers with dual functions of thermal conductivity and electromagnetic shielding of lotus root structure based on sol-gel wet spinning

Textiles that exhibit electromagnetic shielding and high thermal conductivities are valuable materials. Graphene is considered the best candidate material because of its excellent thermal and electrical conductivities. However, there is a challenge that the strong interaction between the layers is easy to aggregate and affect the mechanical properties. At present, the graft modification of graphene can effectively improve its dispersion in solvents. Herein, we fabricate highly oriented composite fibers with “lotus root” structures via sol-gel wet spinning using graphene and aramid nanofiber (ANF) raw materials. The reduced graphene oxide (RGO)/ANFs composite fibers (50RGO/ANF-Ca2+-0.5) exhibit an excellent tensile fracture strength (304.05 MPa). The axial thermal conductivity of a single fiber is 30.42 W/(m·K) due to its highly oriented structure along the axis and dense three-dimensional network structure inside. Thermal infrared imaging shows that the 50RGO/ANF-Ca2+-0.5 textile has a higher surface temperature of 1.1 °C than commercial cotton fabric on human skin, and has a more significant heat dissipation capacity. The 50RGO/ANF-Ca2+-0.5 textiles exhibit electromagnetic shielding efficiencies of up to 49.8 dB. The composite fiber obtained via this low-cost preparation method endows textile with dual functions of thermal conductivity and electromagnetic shielding and has wide application prospects in emerging textiles.

Ultra-fast mechanochemical strategy to obtain stable colloidal dispersions of MWCNT in hydrophilic media: Never has been so easy

In this paper, we present a new protocol that allows the dispersion of multi-wall carbon nanotubes (MWCNT) in the form of stable colloids in a hydrophilic medium up to concentrations of ca. 0.06 % (w/w). The strategy involves using a combination of mechanochemical treatment and surfactants. In this study, we processed MWCNTs with surfactants in a ball mill without using any solvents. The mechanochemical treatment consists of processing mixtures of MWCNTs (0.35 g) with different surfactants (4.5 g of CTAB, 3.6 g of SDS and 4.5 g of F127 as cationic anionic and neutral surfactants, respectively) in a ball mill for only 20 min at 300 rpm. The resulting black powder is then used directly to prepare dispersions in hydro-alcoholic media, which maintain colloidal stability for at least 25 days. Although various strategies for dispersal have been proposed in the literature, many involve time-consuming and multi-step processes with low yields. The MWCNTs modified non-covalently using our protocol are synthesised in a single step with a 100 % yield without any loss of reagents. MWCNT have shown potential in many emerging applications of great interest. Its use necessarily implies the achievement of a good dispersion in different solvents, and this aspect, in the case of hydrophilic media, still does not have a satisfactory answer. The absence of solvent during the mechanochemical treatment is the key aspect of our strategy. This small change represents a significant improvement. We demonstrate the outstanding stability of the obtained suspensions and the preservation of the nano-/microstructure of the MWCNTs, which remains unaltered during their preparation. Furthermore, using environmentally friendly solutions for dispersion makes this protocol a Green Chemistry approach.

Sensitive quantification of acetochlor and metolachlor in water using Taguchi-optimized DLLME coupled with high-performance liquid chromatography

In this study, we developed a method that is sensitive, simple, and environmentally friendly for quantifying acetochlor and metolachlor. This method combines vortex-assisted dispersive liquid–liquid microextraction (DLLME) with high-performance liquid chromatography (HPLC). HPLC operating parameters and extraction parameters for direct and post-extraction analyses of acetochlor and metolachlor were optimized by employing the Taguchi experimental design method. The optimized HPLC parameters for acetochlor and metolachlor were 1.00 mL/min and 1.2 mL/min flow rate, 40 °C column temperature, and 70/30 (ACN/Water) and 80/20 (ACN/Water) at 210 and 230 nm wavelengths, respectively, for the direct injection method. For the DLLME procedure, 1,2-dichloroethane extraction solvent type, acetonitrile, and methanol dispersive solvent type, 400 µL and 300 µL extraction solvent volumes, and 1.0 mL dispersive solvent volume were the optimized DLLME extraction parameters, respectively. The developed and optimized methods for acetochlor and metolachlor analyses exhibited satisfactory validation results, with excellent linearity, indicated by R2 values greater than 0.99. The limit of detection (LOD) and the limit quantification (LOQ) levels of acetochlor and metolachlor were 28.96 to 31.25 µg/L, and 86.87 to 93.75 µg/L for direct injection, and 1.15 to 1.24 µg/L and 3.47 to 3.75 µg/L for post-extraction, respectively. The DLLME recovery values were within the range of 82.6–99.2 % (relative standard deviations-RSD: 4.47–10.13 %) for acetochlor and 91.1–103.4 % (4.31–7.96 %) for metolachlor. Repeatability and reproducibility results (n = 10) of direct injection and post-extraction methods for fortified acetochlor and metolachlor samples displayed very high precision lower than 2 % RSD.

Enhancing Graphene Nanoplatelet Reactivity through Low-Temperature Plasma Modification.

Graphene-based materials have great potential for applications in many fields, but their poor dispersion in polar solvents and chemical inertness require improvements. Low-temperature plasma allows the precise modification of materials, improving the physicochemical properties of the surface and thus creating the possibility of their potential use. Plasma treatment offers the possibility of introducing oxygen functional groups simply, rapidly, and in a controlled way. In this work, a systematic investigation of the effect of plasma modification on graphene nanoplatelets has been carried out to determine the optimal plasma parameters, especially the exposure time, for introducing the highest amount of oxygen functional groups on a surface. Different gases (O2, CO2, air, Ar, and C2H4) were used for this purpose. The chemical nature of the introduced oxygen-containing functionalities was characterized by X-ray photoelectron spectroscopy, and the structural properties of the materials were studied by Raman spectroscopy. The plasma-induced changes have been shown to evolve as the surface functionalities observed after plasma treatment are unstable. The immersion of the materials in liquids was carried out to check the reactivity of carbons in postplasma reactions. Stabilization of the material's surface after plasma treatment using CH3COOH was the most effective for introducing oxygen functional groups.

Highly oxidation resistant and organic dispersible ligand functionalized MXene for triggering performance of lithium ion batteries

Two-dimensional (2D) MXenes are one of the leading members of materials science due to their exceptional dispersion in water, metal-like conductivity, and promising applications in interdisciplinary fields. However, the ease of oxidation and poor dispersion in organic solvents have hindered the advancement of MXenes for futuristic applications. In this study, we developed oxidation-resistant, organic dispersible, environmentally stable, and conductive Ti3C2Tx MXene (Tx = –OH, –O, –F, etc.) by surface modification with 2-Ethylhexyl phosphate (EHP) ligand via a simple condensation reaction at room temperature by optimizing the pH value. The EHP functionalized MXene (MXene-EHP) has excellent dispersion stability in most organic solvents due to EHP ligands favoring excellent compatibility with counterparts. The MXene-EHP/lithium iron phosphate (LiFePO4, LFP) composite was prepared and investigated as an efficient cathode in lithium ion batteries (LIBs). The surface modification with EHP has impeded the surface oxidation of the MXene in MXene-EHP and enhanced the compatibility with the LFP cathode and ionic diffusion in LIBs. MXene-EHP/LFP has delivered an excellent specific capacity of 150 mAh g−1 and 136 mAh g−1 at the initial cycle and after the 500th cycle at 1C rate, respectively in comparison to the bare LFP electrodes with a specific capacity of 118 mAh g−1 and 101 mAh g−1.

Determination of aflatoxins in rice from Penang, Malaysia by dispersive liquid–liquid micro-extraction and LC–MS/MS

Rice is one of the crops cultivated in Malaysia, and it is the main diet for most of the population. In this study, dispersive liquid–liquid micro-extraction (DLLME) and liquid chromatography–tandem mass spectrometry (LC–MS/MS) were used to develop, optimise and validate a reliable, easy-to-use and quick approach to detect aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1) and aflatoxin G2 (AFG2). The extraction recoveries in DLLME were enhanced by the addition of 5% salt, utilising chloroform as the extraction solvent and acetonitrile as the dispersive solvent. The DLLME parameters – the extraction solvent volume, salt concentration and dispersive solvent volume were optimised with Box–Behnken design (BBD) and response surface methodology (RSM). Under optimised experimental conditions, excellent linearity was obtained with a limit of detection (LOD) ranging from 0.125 to 0.25 ng g−1, a limit of quantitation (LOQ) ranging from 0.25 to 0.3 ng g−1 and a correlation value (R 2) of 0.990. The matrix effects were between −11.1% and 19.9%, and recoveries ranged from 87.4% to 117.3%. The optimised and validated method was used effectively to assess aflatoxins contamination in 20 commercial rice samples collected from local supermarkets in Penang, Malaysia. AFB1 was detected at 0.41–0.43 ng g−1 in two rice samples, below the regulatory limit.

Size reduction and water dispersibility improvement of hexagonal boron nitride particles by femtosecond laser irradiation in water

Controlling the size and surface state of inorganic particles, which strongly influence their dispersibility in solvents, is important for diverse applications. Intense femtosecond laser pulses can induce plasma formation in material–dispersed solvents and interact with both materials and solvents. In this study, femtosecond laser pulses are employed to modify hexagonal boron nitride (hBN) particles dispersed in water, with the aim of evaluating the effects of the femtosecond laser process on the size reduction and surface modification of hBN particles. Shadowgraph imaging reveals the formation of the reactive environment in hBN–dispersed water, resulting from the ionization of water molecules which leads to the generation of OH radicals. Evaluation of the hBN particle sizes suggests an overall reduction from 160 to 110 nm after 60 min of irradiation and the generation of nanodots between 5 and 10 nm in size. In addition, it is confirmed that the number of particles with higher zeta potentials increases after the samples are laser-irradiated, suggesting a change in the surface state. Consequently, the duration of hBN particle dispersion in water is significantly increased, with an improvement of at least one order of magnitude, for the laser-irradiated samples. This study presents a demonstration of the formation of a reaction field that affects hBN particles in size and dispersibility in water.

Determination of toxic α-dicarbonyl compounds in sesame oils using dispersive liquid–liquid microextraction coupled with gas chromatography–mass spectrometry

Glyoxal, methylglyoxal, and diacetyl are toxic α-dicarbonyl compounds found in heat-processed foods, including edible oils. Dispersive liquid–liquid microextraction was combined with gas chromatography mass spectrometry to determine the glyoxal, methylglyoxal, and diacetyl contents in sesame oil. Chloroform and methanol were selected as the optimal extraction and dispersive solvents, respectively. The maximum derivatization efficiency was obtained using 500 µg of the derivatization agent, o-phenylenediamine. The derivatization of glyoxal was completed in 1 h, whereas those of methylglyoxal and diacetyl were completed immediately. The optimized method was validated, and was found to exhibit a good linearity, recovery, intraday repeatability, and interday reproducibility. The α-dicarbonyl compound concentrations in the oils were dependent on the roasting temperature. The sesame oil concentrates contained 0–175.4, 0–990.5, and 0–220.9 ng g−1 of glyoxal, methylglyoxal, and diacetyl, respectively. For the perilla oils, the respective concentrations were 0–96.4, 0–410.8, and 0–197.5 ng g−1.

Protective Nanosheet Coatings for Thiophosphate‐Based All‐Solid‐State Batteries

AbstractSuperionic sulfide solid electrolytes (SEs) are of considerable interest for application in solid‐state batteries, but suffer from limited stability. When in combination with state‐of‐the‐art cathode active materials (CAMs), severe degradation at the CAM/SE interface occurs during electrochemical cycling. To improve upon the interfacial stability, inert coatings can be applied to the CAM particles, with the goal of preventing direct contact to the SE. In this study, different methods of depositing coatings, including hexagonal boron nitride, tungsten sulfide and exfoliated ((CH3(CH2)3)4N)4Nb6O17, in the form of nanosheets onto the free surface of a Ni‐rich LiNixCoyMnzO2 (NCM) CAM are examined and compared with one another. While dry coating is shown to produce relatively uniform coatings (good surface coverage), the secondary particle morphology of the NCM makes ball milling as a mechanical deposition method less attractive. In contrast, deposition from dispersions in organic solvents yields protective coatings with a lower degree of surface coverage. The different materials are electrochemically tested in liquid‐ and solid‐electrolyte‐based lithium‐ion batteries. A stabilizing effect from nanosheet coating is only observed for the cells with lithium thiophosphate SE.

(Deep eutectic solvent-ionic liquid)-based ferrofluid a new class of magnetic colloids for determination of tamoxifen and its metabolites in human plasma samples

In this research, a novel category of magnetic colloid was created by immobilizing an ionic liquid on the surface of silica-coated magnetic particles. This was followed by utilizing a natural hydrophobic deep eutectic solvent as a carrier. This magnetic colloid served as an adsorbent in dispersive solid-phase microextraction, combined with liquid chromatography-UV detection, for analyzing tamoxifen and its three active metabolites in plasma samples. After optimizing the effective variables in the analysis, the method underwent validation. Linearity was observed in the calibration model between 0.2 and 5.0 µg/L. The range of the detection limit was found to be 0.2–200.0 µg/L. Assessing the method's precision involved evaluating the intra- and inter-day precision at three analyte concentrations, which determined less than 7.5 % and 11.2 %, respectively. Moreover, the accuracy fell between 94.3 % and 105.1 %. The method's feasibility was evaluated using human plasma samples that ranged in concentrations of tamoxifen, N-desmethyltamoxifen, 4-hydroxytamoxifen, and endoxifen, respectively, from 28.3 to 39.7, 25.9–42.7, ≈1.3, and 3.4–7.2 μg L-1. Among the many benefits of this approach is the removal of the requirement for additional electronic accessories and dispersive solvents. It also minimizes the sample size, making it easily automatable. The method's applicability was demonstrated using human plasma samples, which provided quantification ranges for various tamoxifen metabolites. This technique has a lot of potential for studying the pharmacodynamics, therapeutic drug monitoring, andpharmaceutical kineticsof tamoxifen and its metabolites in bodily fluids, which will help with clinical research and drug analysis.

First synthesis of 2D materials by hypergolic reactions and evaluation of their dispersions for ink formulation: hexagonal boron nitride and fluorinated carbon nanosheets

Hypergolic reactions have emerged as a new synthetic approach enabling the rapid production of a diverse set of materials at ambient conditions. While hypergolic reactions bear several similarities to the well-established flame spray pyrolysis (FSP), the former has only recently been demonstrated as a viable approach to materials synthesis. Here we demonstrate a new pathway to 2D materials using hypergolic reactions and expand the gallery of nanomaterials synthesized hypergolically. More specifically, we demonstrate that ammonia borane complex, NH3BH3, or 4-fluoroaniline can react hypergolically with fuming nitric acid to form hexagonal boron nitride/fluorinated carbon nanosheets, respectively. Structural and chemical features were confirmed with x-ray diffraction, infrared, Raman, XPS spectroscopies and N2 porosimetry measurements. Electron microscopy (SEM and TEM) along with atomic force microscopy (AFM) were used to characterize the morphology of the materials. Finally, we applied Hansen affinity parameters to quantify the surface/interfacial properties using their dispersibility in solvents. Of the solvents tested, ethylene glycol and ethanol exhibited the most stable dispersions of hexagonal boron nitride (h-BN). With respect to fluorinated carbon (FC) nanosheets, the suitable solvents for high stability dispersions were dimethylsulfoxide and 2-propanol. The dispersibility was quantified in terms of Hansen affinity parameters (δ d, δ p,δ h) = (16.6, 8.2, 21.3) and (17.4, 10.1, 14.5) MPa1/2 for h-BN and FC, respectively.

Birefringence Behaviors of Cellulose Nanocrystals under Varied Concentrations, Ultrasonication Treatments, and Different Solvents

Self-assembly of cellulose nanocrystal (NCC) in suspension has unique characteristics under polarize observation which is called as birefringence behaviors. However, the study about these phenomena is lacking especially when the NCC is prepared in dried powder form. Here, we reported the behaviors of commercial NCC obtained from CelluForce NCC, NCV100-NASD90 dispersed in different concentrations (0.1% to 8% weight/weight); ultrasonic times (0 to 45 minutes); solvents (Benzene, N,N-Dimethylacetamide (DMA), Ethanol, Dimethylformamide, Acetone, Acetic acid 1%, and Water) for their birefringence manners. In addition, nanocellulose obtained from TEMPO mediated oxidation and organic acid hydrolysis were also reported. Dried powder NCC showed shear thickening behavior at high concentration and well-dispersed at acetic acid and water solvent indicated the redispersable NCC. While, cellulose NCC, NCV100-NASD90 considerably low dispersion in non-polar solvents. Birefringence appears only when the suspension was in anisotropic state due to stirring. As sonication times increased, the birefringence clearly visible which suggested the defibrillation of aggregated cellulose crystal. The results of this study authenticated that redispersable NCC could be obtained from dried powder cellulose and provided birefringence behavior by managing concentration levels, sonication times and perfect solvents to dilute.

Green Analytical Toxicology procedure for determination of ketamine, its metabolites and analogues in oral fluid samples using dispersive liquid-liquid microextraction (DLLME).

New psychoactive substances (NPS) are often synthesized via small changes in the molecular structure, producing drugs whose effect and potency are not yet fully known. Ketamine is one of the oldest NPS, with therapeutic use in human and veterinary medicine authorized in several countries, being metabolized mainly into norketamine and 6-hydroxy-norketamine. Furthermore, two structural analogues of ketamine have recently been identified, deschloroketamine and 2-fluorodeschloroketamine, marketed as drugs of abuse. To comply with Green Analytical Toxicology (GAT) fundamentals, miniaturized techniques such as dispersive liquid-liquid microextraction (DLLME) were employed to determine toxicants in biological fluids. An analytical method for determining ketamine, its metabolites and its analogues in oral fluid was fully developed and validated by using DLLME and liquid chromatography-tandem mass spectrometry (LC-MS-MS). The extraction parameters were optimized by multivariate analysis, obtaining the best conditions with 200 μL of sample, 100 μL of methanol as dispersive solvent and 50 μL of chloroform as extractor solvent. Linearity was obtained from 10 to 1,000 ng/mL, with limit of detection (LOD) and lower limit of quantification (LLOQ) at 10 ng/mL. Imprecision (% relative standard deviation) and bias (%) were less than 8.2% and 9.5%, respectively. The matrix effect did not exceed 10.6%, and the recovery values varied from 24% to 42%. No matrix interference and good selectivity in the evaluation of 10 different sources of oral fluid and 42 drugs at 500 ng/mL, respectively, were observed. The method was applied in the analysis of 29 authentic oral fluid samples and had its green characteristic evaluated by three different tools: the Green Analytical Procedure Index (GAPI), the Analytical Eco-Scale and the Analytical GREEnness (AGREE) metrics.

Multi-Interfacial Confined Assembly of Colloidal Quantum Dots Quasisuperlattice Microcavities for High-Resolution Full-Color Microlaser Arrays.

Colloidal quantum dots (CQDs) are considered a promising material for the next generation of integrated display devices due to their designable optical bandgap and low energy consumption. Owing to their dispersibility in solvents, CQD micro/nanostructures are generally fabricated by solution-processing methods. However, the random mass transfer in liquid restricts the programmable construction in macroscopy and ordered assembly in microscopy for the integration of CQD optical structures. Herein, a multi-interfacial confined assembly strategy is developed to fabricate CQDs programmable microstructure arrays with a quasisuperlattice configuration through controlling the dynamics of three-phase contact lines (TPCLs). The motion of TPCLs dominates the division of liquid film for precise positioning of CQD microstructures, while pinned TPCLs control the solvent evaporation and concentration gradient to directionally drive the mass transfer and packing of CQDs. Owing to their long-range order and adjustable structural dimensions, CQD microring arrays function as high-quality-factor (high-Q) lasing resonant cavities with low thresholds and tunable lasing emission modes. Through the further surface treatment and liquid dynamics control, the on-chip integration of red (R), green (G), and blue (B) multicomponent CQD microlaser arrays are demonstrated. The technique establishes a new route to fabricate large-area, ultrahigh-definition, and full-color CQD laser displays.

A Quantitative Approach to Characterize the Surface Modification on Nanoparticles Based on Localized Dielectric Environments.

Nanoparticles (NPs) are utilized for the functionalization of composite materials and nanofluids. Although oxide NPs (e.g., silica (SiO2)) exhibit less dispersibility in organic solvents or polymers due to their hydrophilic surface, the surface modification using silane coupling agents can improve their dispersibility in media with low dielectric constants. Herein, SiO2 NPs were functionalized using octyltriethoxysilane (OTES, C8) and dodecyltriethoxysilane (DTES, C12), wherein the degrees of surface modification of SiO2@C8 and SiO2@C12 were quantitatively evaluated based on the ratio of modifier to surface silanol group (θ) and the volume fraction of organic modifier to total particle volume (ϕR). The variations of surface properties were revealed by analyzing the Hansen solubility parameters (HSP). Particularly, the surface modification using OTES or DTES significantly affected the polarity (δP) of NPs. The local dielectric environments of surface-modified SiO2 NPs were characterized using a solvatochromic dye, Laurdan. By analyzing the peak position of the steady-state emission spectrum of Laurdan in a NP suspension, the apparent dielectric environments surrounding NPs (εapp) were obtained. A good correlation between ϕR and εapp was observed, indicating that ϕR is a reliable quantity for understanding the properties of surface-modified NPs. Furthermore, the generalized polarization (GP) of NPs was investigated. The surface-modified SiO2 NPs with higher ϕR (≥0.15) exhibited GP > 0, suggesting that the modifiers are well-organized on the surface of NPs. The localized dielectric environment surrounding NPs could be predicted by analyzing the volume fraction of nonpolar moieties derived from modifiers. Alternatively, εapp and GP can be utilized for understanding the properties of inorganic-organic hybrid NPs.