Organic Dispersion Research Articles

A Win–Win Strategy to Fabricate Multifunctional Doping Materials from Cationic Dyes and Negatively Charged Biomass (Cellulose Nanocrystals)

AbstractIf optical probes with different sensitivity could be performed simultaneously in their hard states (e.g., film), soft states (e.g., gel), and solution states, their sensing accuracy could be enhanced due to the highly mutual calibration. The biomass of cellulose nanocrystals is less compatible with commonly used organo‐fluorescent dyes and require chemical modification to improve their application performance, but this leads to the less‐effective material cost. In this work, depending on the electrostatic attractions between the negatively charged polymer matrix with cationic dyes, the cellulose nanocrystals (CNCs)‐based emissive membranes were prepared by vacuum filtration method. Then, the resulting materials were transformed into hydrogels, or dispersed into water solutions, or further absorbed into commercially available polymer spheres and filter papers, resulting in the optical devices with different states. It is worth mentioning that this preparation process does not require chemical modification of cellulose nanocrystals or the addition of organic dispersants, thus greatly reducing the material cost. Finally, the sensing behaviors toward several important stimuli, such as temperature, pollutants like Cr (VI) and pH changes, were successfully carried out. Overall, our research works highlighted a processable way to fabricate fluorescent, water‐dispersible, portable, long‐time‐storable, cost‐effective sensors to meet versatile application requirements.

Photocatalytic Hydrogen Generation in Surfactant-Free, Aqueous Organic Nanoparticle Dispersions.

Hydrogen generation in electrostatically stabilized, aqueous organic nanoparticle dispersions is investigated. For this purpose, organic nanoparticle dispersions are synthesized in water by nanoprecipitation from tetrahydrofuran and stabilized by charging through strong molecular electron acceptors. The dispersions are stable for more than 10 weeks on the shelf and during the photocatalytic process, despite the continuous transfer of charges between the reactants. The hydrogen generation in the electrostatically stabilized dispersions outperforms the hydrogen generation in organic nanoparticle dispersions which contain the common stabilizer sodium dodecyl sulfate.

Low-energy micron dispersion of entangled polymers based on phase inversion composition of emulsion

Low-energy micron dispersion of entangled polymers based on phase inversion composition of emulsion

Boosting electrochemical performance of single-walled carbon nanotube three-dimensional architectures through appropriate selection of organic dispersant

Boosting electrochemical performance of single-walled carbon nanotube three-dimensional architectures through appropriate selection of organic dispersant

Characterization and Dissolution Mechanism of Low-Molecular-Weight Organic Acids or Inorganic Mesoporous Particle-Based Piperine Amorphous Solid Dispersions.

The objective of the current study is to prepare amorphous solid dispersions (ASDs) containing piperine (PIP) by utilizing organic acid glycyrrhizic acid (GA) and inorganic disordered mesoporous silica 244FP (MSN/244FP) as carriers and to investigate their dissolution mechanism. The physicochemical properties of ASDs were characterized with scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), and differential scanning calorimetry (DSC). Fourier transform infrared spectroscopy (FTIR) and one-dimensional proton nuclear magnetic resonance (1H NMR) studies collectively proved that strong hydrogen-bonding interactions formed between PIP and the carriers in ASDs. Additionally, molecular dynamic (MD) simulation was conducted to simulate and predict the physical stability and dissolution mechanisms of the ASDs. Interestingly, it revealed a significant increase in the dissolution of amorphous PIP in ASDs in in vitro dissolution studies. Rapid dissolution of GA in pH 6.8 medium resulted in the immediate release of PIP drugs into a supersaturated state, acting as a dissolution-control mechanism. This exhibited a high degree of fitting with the pseudo-second-order dynamic model, with an R2 value of 0.9996. Conversely, the silanol groups on the outer surface of the MSN and its porous nanostructures enabled PIP to display a unique two-step drug release curve, indicating a diffusion-controlled mechanism. This curve conformed to the Ritger-Peppas model, with an R2 > 0.9. The results obtained provide a clear evidence of the proposed transition of dissolution mechanism within the same ASD system, induced by changes in the properties of carriers in a solution medium of varying pH levels.

Influence of imidazolium ionic liquids as organic filler dispersant on electrical properties of chitin/epoxy composites

Influence of imidazolium ionic liquids as organic filler dispersant on electrical properties of chitin/epoxy composites

Modeling the Effect of Sulfur Composition in Dispersed Systems Involving Organosulfur Compounds

Background:: Organosulfur compounds within petroleum have far-reaching consequences for the refining industry, combustion of petroleum products, and environmental quality. They induce corrosion in refining equipment, hamper the efficient burning of petroleum products, and contribute to environmental degradation. In high-density asphalt crudes, these compounds are predominantly concentrated within asphaltenes. However, crude oils with extremely high sulfur content, may be distributed across the four constituent families defined by the SARA analysis of crude oil composition. These compounds, characterized by differing polarities, can trigger the formation of a dispersed phase, whose destabilization results in tube clogging issues. Methods:: The research problem focuses on understanding how sulfur composition affects the formation of a dispersed phase in low-polarity organic dispersion media for sulfur-containing hydrocarbons. It is investigated because the presence of sulfur in crude oil significantly affects the behavior of dispersed phases, which can result in operational and environmental quality issues to comprehensively assess the impact of sulfur composition on the dynamics and stability of this dispersed phase, we introduce a mesoscopic model based on the master equation. This model considers the molecular structure of system components and their molecular properties, established through computational quantum chemistry and statistical thermodynamics tools Results:: While our research focuses on a two-phase system, our theoretical insights suggest that increased sulfur content escalates the likelihood of destabilizing the dispersed phase. This adverse effect can be mitigated by incorporating additives capable of reducing the polarizability of the dispersion medium. The novelty lies in the development of a stochastic model to predict the dynamics of dispersed phase formation in sulfur-containing hydrocarbons. This model considers molecular interactions and stochastic processes, offering insights into the influence of sulfur composition on phase behavior. Conclusion:: A stochastic model, based on molecular structure, predicts accelerated formation with increased sulfur concentration, reaching non-equilibrium steady states. Limitations include ad hoc transition probabilities and the exclusion of factors like density and viscosity. Real crudes, with complex compositions, may exhibit different behavior. The presence of sulfur in the dispersion medium enhances the stability of the dispersed system. Our work sheds light on the intricate interplay between sulfur content and the performance of petroleum systems, offering potential solutions to mitigate these issues. Quantitative results include accelerated dispersed phase formation with increased sulfur concentration. Qualitatively, molecular interactions and stochastic processes were explored, highlighting sulfur's impact on phase dynamics.

Application of organic phosphonic acid dispersant in the separation and flotation of chalcopyrite and serpentine

Application of organic phosphonic acid dispersant in the separation and flotation of chalcopyrite and serpentine

Enhancing capillary action of acidified paper to achieve uniform deacidification and long-lasting aging resistance

Enhancing capillary action of acidified paper to achieve uniform deacidification and long-lasting aging resistance

Impact of water solvation on the charge carrier dynamics of organic heterojunction photocatalyst nanoparticle dispersions.

Organic heterojunction nanoparticles (NP) have recently gained significant interest as photocatalysts for visible light-driven hydrogen production. Whilst promising photocatalytic efficiencies have been reported for aqueous NP dispersions, the underlying dynamics of photogenerated charges in such organic heterojunction photocatalysts and how these might differ from more widely studied dry heterojunction films remain relatively unexplored. In this study, we combine transient optical spectroscopies over twelve orders of magnitude in time, using pulsed and continuous light illumination, to elucidate the differences in the charge carrier dynamics of heterojunction NP dispersions, dried NP films, and bulk heterojunction films prepared by spin coating. The ultrafast fast (ps to ns) transient absorption results show efficient charge generation and indistinguishable nanosecond charge recombination decay kinetics of separated charges in all three samples. In contrast, on the slower μs to ms time range, the decay kinetics of heterojunction NP dispersion exhibited up to 15-fold larger amplitude and more than one order of magnitude slower decay of the photogenerated charges than those in films. The analysis of the nanomorphology, NP surfactant, polymer residual metal content and local polar environment suggest that the longer lifetime differences (in ms) in the charge recombination in NP dispersion are mostly associated with a charge carrier stabilisation on a shallow density of states on the NP surface of ∼350 meV by interaction with local water environment, resulting in suppressed charge recombination. The lengthening of NP dispersion charge carrier lifetime is discussed regarding the energetic loss for function and their implications in photocatalysis.

Functionalization of Violet Phosphorus Quantum Dots with Azo-Containing Star-Shape Polymer for Optically Controllable Memory

Quantum dots (QDs) are emerging as promising candidates for innovative memristive materials, owing to their distinct surface, quantum size, and edge effects. Recent research has focused on tailoring QDs with specific organic molecules to fine-tune charge transfer states between the host and grafted species, as well as enhancing their dispersibility and processability. Violet phosphorus (VP), a newly discovered two-dimensional phosphorus allotrope, offers excellent carrier dynamics, predictable modifiability, and superior oxidation resistance, making it a promising contender in this domain. In this study, we synthesized a rich azobenzene-containing star-shaped polymer diazonium salt (AzoSPD) to functionalize violet phosphorus quantum dots (VPQDs), with the dual objectives of enhancing organic dispersibility and introducing photo-switching capabilities. The synthesized AzoSPD–VPQDs exhibit intramolecular charge transfer characteristics under electrical stimuli of ambient conditions, displaying significant non-volatile rewriteable memory properties and a substantial switching ratio exceeding 2 × 103. Furthermore, the high resistance state (HRS) current can be enhanced by nearly 40 times under 465 nm illumination, enabling optoelectronic information sensing and storage within a single device. This work not only provides insights into enhancing the optoelectronic properties of QDs through functional organic molecular modification but also represents a pioneering exploration of the potential applications of VPQDs in novel memristors.

Influence of eco-friendly dispersants on the properties of a lateritic soil-based mortar

Influence of eco-friendly dispersants on the properties of a lateritic soil-based mortar

APTMS‐Modified Silica as a Thin‐Film Nanocomposite Forward Osmosis Membranes: Towards Enhanced Selectivity and Dye Rejection Stability for Congo Red and Rhodamine B

AbstractFumed silica (SiO2) is often applied in the modification of thin‐film composite (TFC) forward osmosis (FO) membranes due to its hydrophilicity. However, a key challenge to be solved is to improve its compatibility with organic matrices and dispersion in the material. In this study, we synthesized well‐designed nanoparticles of (3‐aminopropyl)trimethoxysilane‐modified SiO2 (APTMS‐SiO2) and applied them for the first time in the preparation of FO membranes. Furthermore, we systematically investigated the effects of different pretreated SiO2, SiO2 dosages, draw solution types, and concentrations on FO membranes. The results showed that APTMS‐SiO2 thin‐film nanocomposite with a silica dosage of 0.1 wt.% has the highest water permeate flux (Jw) (26.25 LMH, 370.43 % higher than the control TFC of 5.58 LMH) and the minimum specific reverse solute flux (SRSF) of 0.17 g/L with 1 M NaCl as the draw. The incorporation of APTMS effectively prevented mutual agglomeration of SiO2 and improved its dispersion. The Jw of 13.36 LMH after seven cycles and the rejection of above 96.6 % for Congo Red and 95.8 % for Rhodamine B indicated potential reusability and dye rejection. This work presents an alternative approach to prepare FO membranes with enhanced water flux and increased selectivity, and it also offers insights for the treatment of printing and dyeing wastewater using FO.

The syntheses of fluorescein-based conjugated microporous polymers by direct arylation polymerization and fluorescence sensing Fe3+ in aqueous solutions

Determination of ferri ions in environment and human bodies is very important for environmental protection and disease diagnosis. Recently, conjugated microporous polymers (CMPs) used for fluorescence sensing metal ions have attracted much attention, but this technique is done in organic solvents. In this study, the two new fluorescein-based CMPs named FLEDOT and FLBTh were synthesized by "greener method", direct arylation polymerization, with tetraiodofluorescein sodium salt (TIFS) and 3,4-ethylenedioxy thiophene or 2,2'-bithiophene. Pleasely, the prepared fluorescein-based CMPs can fluorescently sense for Fe3+ in water with high sensitivity and selectivity. The quenching constants (KSV) of FLEDOT and FLBTh are 1.51×104 and 1.09×104Lmol-1, and the limits of detection (LODs) as low as 1.99×10-10 and 2.75×10-10molL-1, which are comparable to the sensitivity found in organic solvents' dispersions such as N,N-dimethylformamide (DMF)' dispersions. UV-Vis absorption spectra show that the fluorescence quenching mechanisms of Fe3+ are absorption competition quenching process and energy transfer process.

Preparation of the EPDM/PBMA organic dispersion based on in-situ polymerization: Application in the protection of flexible electronic devices

Preparation of the EPDM/PBMA organic dispersion based on in-situ polymerization: Application in the protection of flexible electronic devices

Effect of molecular environment on asphaltene aggregation: a molecular dynamics study

Asphaltene deposition poses a significant threat to the safe production of crude oil as it tends to occur in forming porous media, wellbores, pipelines, and refining equipment. It is also responsible for the high viscosity of crude oil, making it challenging to recover heavy crude oil. This study investigates the impact of aliphatic chain length on asphaltene aggregation and the molecular properties of organic solvents and dispersants interacting with asphaltenes. To achieve this, two model asphaltenes, M1 and C5Pe, were used in molecular dynamics simulations using radial distribution function, root means square displacement, diffusion coefficient, solubility parameter, cohesion energy density, and interaction energy as characterization parameters. The simulations revealed that the aggregation onset of C5Pe and M1 occurs at 2–5 Å at room temperature and pressure, and π–π stacking is the primary mode of aggregation, with the presence of heteroatomic groups providing additional forces for stable aggregation. Additionally, it was found that the π–π interactions weakened with the increase of the side chain length. The study also investigated the molecular behavior of asphaltenes in six organic solvents and found that M1 was more soluble in aromatic solvents than C5Pe, and undesirable solvents could induce asphaltene aggregation. Furthermore, the effect of five dispersants on asphaltene aggregation was explored, with PIBSI, BEHP, B-DBSA, CTAB, and benzoic acid showing decreasing dispersing ability in that order at lower concentrations. However, at higher concentrations, the effect of some dispersants diminishes and triggers self-aggregation behavior.

Regulating Organic Dopant Dispersion in Polymer Matrices for Concentration‐Controlled Color‐Tunable Organic RTP Emissions

AbstractMulti‐aryl conjugated organic molecules have intrinsically poor compatibility with most polymers, although they can be dispersed into polymer matrices by solution casting film. This work proposes that this property can be used to obtain diverse dispersion states and realize unique room temperature phosphorescence (RTP). Herein, cyano‐ and amide‐containing N‐phenylcarbazoles (2Q5X, 2J5X) are doped into different polar and rigid PVA and PMMA. 2J5X/PVA emits blue and green RTP after 254 and 365 nm light excitation, respectively, whereas 2Q5X/PVA emits green RTP bearing excitation wavelength‐dependent blue‐emitting shoulder. When 2Q5X is doped into PMMA, this blue RTP becomes dominant due to the increase in molecular dispersion ratio. Combined with the investigations on RTP properties of low doping concentration polymers and crystalline and amorphous states, the blue RTP and green RTP are attributed to the emissions of the isolated molecule and the clustering molecules, respectively. This work reveals that regulating the dispersion of organic dopants in polymers can provide unique and diverse RTP properties.

Wound Coating Collagen-Based Composites with Ag Nanoparticles: Synthesis, Structure and Biological Activity

The search for materials for a new generation of wound coatings is important due to the increase in antibiotic-resistant microorganisms and the number of patients with untreatable chronic purulent wounds. Metal nanoparticles, specifically silver nanoparticles, have antimicrobial activity and do not induce known bacterial resistance. To obtain new Ag-containing nanocomposites, type I collagen was extracted by an enzyme–acid method from cattle tendons. Silver nanoparticles were obtained by an environmentally safe method, metal-vapor synthesis (MVS), which enables obtaining metal nanoparticles without impurities. For this, metal vapors were cocondensed in a vacuum of 10−2 Pa on the walls of a quartz reactor cooled to 77 K using acetone as an organic dispersion medium. The composition of the collagen surface was determined by XPS using the spectra of C1s, N1s, and O1s. The presence of a peak with a binding energy of approximately 368.57 eV in the Ag 3d5/2 spectrum indicates the state of Ag0 silver atoms in the nanocomposite. SEM images showed that collagen contributes to the effective stabilization of Ag nanoparticles with an average size of 13.0 ± 3.5 nm. It was found that collagen is non-toxic and biocompatible with skin cells and fibroblasts. The collagen–Ag nanoparticle nanocomposites exhibited antimicrobial activity against bacteria Bacillus subtilis, Escherichia coli, and fungi Aspergillus niger.

Dry liquid metals stabilized by silica particles: Synthesis and application in photothermoelectric power generation

Gallium-based room-temperature liquid metals (LMs) have unique physicochemical properties; however, their high surface tension, low flowability, and high corrosiveness to other materials limit their advanced processing (including precise shaping) and application. Consequently, LM-rich free-flowing powders, named "dry LMs" that offer the inherent advantages of dry powders, should play a critical role in expanding the application scope of LMs. A general method of preparing silica-nanoparticle-stabilized LMs in the form of LM-rich powders (>95wt% LM) is developed. Dry LMs can be simply prepared by mixing LMs with silica nanoparticles in a planetary centrifugal mixer in the absence of solvents. As a sustainable dry-process route alternative to wet-process routes, this ecofriendly and simple method of dry LM fabrication has several advantages, e.g., high throughput, scalability, and low toxicity owing to the lack of organic dispersion agents and milling media. Moreover, the unique photothermal properties of dry LMs are used for photothermal electric power generation. Thus, dry LMs not only pave the way for the use of LMs in powder form but also provide a new opportunity for expanding their application scope in energy conversion systems.

Sensitive determination of polybrominated diphenyl ethers (PBDEs) in water and milk by effervescence-enhanced switchable hydrophilic-hydrophobic solvent-based salting-out microextraction and high-performance liquid chromatography with photodiode array detection (HPLC-PDA)

Here is reported effervescent reaction-enhanced switchable hydrophilic-hydrophobic solvent-based salting-out microextraction (ERSSM) with high-performance liquid chromatography with photodiode array detection (HPLC-PDA) for the preconcentration, extraction, and trace-level determination of polybrominated diphenyl ethers (PBDEs) in milk and water. The important variables were rigorously optimized to be 150 µL of hexanoic acid as the extraction solvent, 400 µL of Na2CO3 as the alkaline source, 350 µL of H2SO4 solution as the acid source, and NaCl as the salting-out agent. The optimized conditions provided a linear range from 0.2 to 50 µg L−1 with limits of detection and quantitation from 0.026 to 0.085 µg L−1 and 0.087 to 0.28 µg L−1 for six PBDEs. The intra-day and inter-day precision values were from 2.48% to 6.75%, and the fortified recoveries for PBDEs were between 78.06% and 103.07% in water and milk samples. The developed procedure avoids the use of a traditional organic disperser and mechanical mixing allowing the determination of PBDEs outdoors by synchronous extraction method and high efficiency for the analytes. These advantages suggest a high potential for the routine monitoring of PBDEs in liquid food and environmental samples.