Types Of Colloids Research Articles

Manipulation of artificial and living small objects by light driven diffusioosmotic flow

Here we report on light-triggered generation of local flow utilizing a bio-compatible non-ionic photo-active surfactant. The mechanism is based on diffusioosmotic phenomenon, where the gradient of relative concentration with respect to different chemical species near a surface leads to an osmotic pressure gradient driving liquid flow along the surface. The application of a photo-responsive surfactant allows for easy and reversible changes in concentration gradient by positioning a light source at the desired place. Along with the so-inscribed concentration gradient one can change reversible the direction and strength of the flow even in a closed system. The phenomenology of light-driven diffusioosmotic flow (LDDO) can be used in a rather flexible way: colloids can be gathered or dispersed and bio-compatibility extends the range of colloid types also to living microorganisms such as soil bacterium Pseudomonas putida. We show that DO flow can be considered a versatile method to set hydrodynamic conditions along the sample for investigating the motility of living cells. Further advantages of employing LDDO are the flexibility of flow generation in a reversible way and with spatiotemporal control, without the need to either change the channel geometry by loading a different device, or the periphery of pumps and connectors.

Lane formation in gravitationally driven colloid mixtures consisting of up to three different particle sizes.

Brownian dynamics simulations are utilized to study segregation phenomena far from thermodynamic equilibrium. In the present study, we expand upon the analysis of binary colloid mixtures and introduce a third particle species to further our understanding of colloidal systems. Gravitationally driven, spherical colloids immersed in an implicit solvent are confined in two-dimensional linear microchannels. The interaction between the colloids is modeled by the Weeks-Chandler-Andersen potential, and the confinement of the colloids is realized by hard walls based on the solution of the Smoluchowski equationin half space. In binary and ternary colloidal systems, a difference in the driving force is achieved by differing colloid sizes but fixed mass density. We observe for both the binary and ternary systems that a driving force difference induces a nonequilibrium phase transition to lanes. For ternary systems, we study the tendency of lane formation to depend on the diameter of the medium-sized colloids. Here we find a sweet spot for lane formation in ternary systems. Furthermore, we study the interaction of two differently sized colloids at the channel walls. Recently we observed that driven large colloids push smaller colloids to the walls. This results in small particle lanes at the walls at early simulation times. In this work we additionally find that thin lanes are unstable and dissolve over very long time frames. Furthermore, we observe a connection between lane formation and the nonuniform distribution of particles along the channel length. This nonuniform distribution occurs either alongside lane formation or in shared lanes (i.e., lanes consisting of two colloid types).

A novel synthesis method of magnetic Janus particles for wastewater applications

HypothesisMagnetic particles are widely used in many adsorption and removal processes. Among the many types of magnetic colloids, magnetic Janus particles offer significant possibilities for the effective removal of several components from aqueous solutions. Nevertheless, the synthesis of structures integrating different types of materials requires scalable fabrication processes to overcome the limitations of the available methodologies. Herein, we hypothesized a fabrication process for dual-surface functionalized magnetic Janus particles. ExperimentsThe primary silica particles with surface-attached amine groups are further asymmetrically modified by iron oxide nanoparticles, exploiting Pickering emulsion and electroless deposition techniques. The dual surface functionality of the particles is designed for its versatility and demonstrated in two wastewater-related applications. FindingsWe show that our design can simultaneously remove chromium (VI) and phenol from aqueous solution. The fabricated magnetic-responsive Janus particles are also an effective adsorbent for genomic Deoxyribonucleic acid (DNA) and show superior performance to commercial magnetic beads. Thus, this study provides a novel platform for designing magnetic Janus particles with multifunctional surfaces for wastewater treatment applications.

Quality Characteristics of Vegan Mayonnaise Produced Using Supercritical Carbon Dioxide-Processed Defatted Soybean Flour.

Emulsifiers, like egg yolk (EY), are necessary for the formation of mayonnaise, which is an oil-in-water type of colloid. This study aimed to assess the potential of defatted soybean powder treated with supercritical carbon dioxide (DSF) to enhance the quality of plant-based mayonnaise as plant-based alternatives gain popularity. This study involved the production of DSF and the comparison of its quality attributes to those of mayonnaise made with varying amounts of control soy flour (CSF), DSF, and EY. It was found that mayonnaise made with an increased quantity of DSF showed better emulsion stability, viscosity, and a smaller, more uniform particle size when compared with CSF mayonnaise. Additionally, DSF mayonnaise was generally rated higher in sensory evaluation. The addition of approximately 2% DSF positively influenced the emulsion and sensory properties of the vegan mayonnaise, indicating that DSF is a promising plant-based alternative emulsifier for the replacement of animal ingredients.

Self-organization of active colloids mediated by chemical interactions.

Self-propelled colloidal particles exhibit rich non-equilibrium phenomena and have promising applications in fields such as drug delivery and self-assembled active materials. Previous experimental and theoretical studies have shown that chemically active colloids that consume or produce a chemical can self-organize into clusters with diverse characteristics depending on the effective phoretic interactions. In this paper, we investigate self-organization in systems with multiple chemical species that undergo a network of reactions and multiple colloidal species that participate in different reactions. Active colloids propelled by complex chemical reactions with potentially nonlinear kinetics can be realized using enzymatic reactions that occur on the surface of enzyme-coated particles. To demonstrate how the self-organizing behavior depends on the chemical reactions active colloids catalyze and their chemical environment, we consider first a single type of colloid undergoing a simple catalytic reaction, and compare this often-studied case with self-organization in binary mixtures of colloids with sequential reactions, and binary mixtures with nonlinear autocatalytic reactions. Our results show that in general active colloids at low particle densities can form localized clusters in the presence of bulk chemical reactions and phoretic attractions. The characteristics of the clusters, however, depend on the reaction kinetics in the bulk and on the particles and phoretic coefficients. With one or two chemical species that only undergo surface reactions, the space for possible self-organizations are limited. By considering the additional system parameters that enter the chemical reaction network involving reactions on the colloids and in the fluid, the design space of colloidal self-organization can be enlarged, leading to a variety of non-equilibrium structures.

Inhibitory potential of Eugenia sulcata essential oil and its nanoemulsions against Aspergillus spp.

Natural products are in the spotlight of novelty for obtaining ecofriendly agents against pests. In this context, searching for new antifungal alternatives for control of grain microorganism is recommended. In this paper we show a brief description of nanoemulsification as a valuable tool for modification of essential oil properties. Low energy method was used for the preparation of Eugenia sulcata nanoemulsion. This approach was also used for the preparation of this type of colloid with β-caryophyllene, the main component of this essential oil. Especially regarding Aspegillus parasiticus, it was possible to observe increment of bioactivity by nanoemulsification of E. sulcata. This short communication contributes to better knowledge of mechanism in the rationalization of antifungal nanoemulsions based in essential oil and its main constituents, providing relevant insights that can be used for other complex volatile mixtures.

E. coli cotransport with composite colloid in unsaturated porous media: Multi-risk on migration and biomolecular response

The diversity of colloidal types and the differences in the composite ratios in porous media are important factors governing the migration and biological risk of pathogenic microorganisms in the subsurface environment. In this study, E. coli O157:H7 was subjected to co-migration experiments with different compositions of the composite colloid montmorillonite (MMT)-Fe2O3, and the biomolecular response of E. coli under the action of colloids was analyzed by Raman spectroscopy to quantify the risk of E. coli under the action of composite colloids based on both. The results showed that Fe2O3 colloids inhibited E. coli migration mainly by electrostatic adsorption and reduced E. coli metabolism. MMT colloid inhibited E. coli migration mainly by blockage, and E. coli metabolism increased, and surface macromolecules decreased to reduce E. coli adhesion. MMT-Fe2O3 complex colloids inhibited migration through electrostatic attraction between the two and formation of cohesive colloids, with reduced E. coli metabolism and insignificant biomolecular response. It was briefly assessed that the composite colloids reduced E. coli risk less strongly than single colloids, stemming from the difference in the mechanism of influence and the actual need to consider colloid interactions. This conclusion can inform the management and control of pathogen risk in porous media environments.

A Study on the Structural and Digestive Properties of Rice Starch-Hydrocolloid Complexes Treated with Heat-Moisture Treatment.

Rice starch-hydrophilic colloid complexes (SHCs) were prepared by incorporating xanthan gum and locust bean gum into natural rice starch. Subsequently, they underwent hygrothermal treatment (H-SHC) to investigate their structural and digestive properties with varying colloid types and added amounts of H-SHC. The results demonstrated that heat-moisture treatment (HMT) led to an increase in resistant starch (RS) content in rice starch. This effect was more pronounced after the addition of hydrophilic colloid, causing RS content to surge from 8.42 ± 0.39% to 38.36 ± 3.69%. Notably, the addition of locust bean gum had a more significant impact on enhancing RS content, and the RS content increased with the addition of hydrophilic colloids. Enzyme digestion curves indicated that H-SHC displayed a lower equilibrium concentration (C∞), hydrolysis index (HI), and gluconeogenesis index (eGI). Simultaneously, HMT reduced the solubility and swelling power of starch. However, the addition of hydrophilic colloid led to an increase in the solubility and swelling power of the samples. Scanning electron microscopy revealed that hydrophilic colloid encapsulated the starch granules, affording them protection. X-ray diffraction (XRD) showed that HMT resulted in the decreased crystallinity of the starch granules, a trend mitigated by the addition of hydrophilic colloid. Infrared (IR) results demonstrated no formation of new covalent bonds but indicated increased short-range ordering in H-SHC. Rapid viscosity analysis and differential scanning calorimetry indicated that HMT substantially decreased peak viscosity and starch breakdown, while it significantly delayed the onset, peak, and conclusion temperatures. This effect was further amplified by the addition of colloids. Rheological results indicated that H-SHC displayed lower values for G', G″, and static rheological parameters compared to natural starch. In summary, this study offers valuable insights into the development of healthy, low-GI functional foods.

Determination of remdesivir in human plasma using (deep eutectic solvent-ionic liquid) ferrofluid microextraction combined with liquid chromatography

A microextraction technique based on ferrofluids was developed for the preconcentration and quantification of Remdesivir in human plasma samples. This method utilized a new type of magnetic colloids created by combining silica-coated magnetic particles with modified ionic liquid and natural hydrophobic deep eutectic solvent as the carrier liquid. The efficiency of the sorption and desorption steps was optimized using a chemometrics approach. Under the optimized conditions, the calibration curve exhibited linearity in the concentration range of 0.5 to 500.0 μg L−1, with a limit of detection and quantification of 0.2 and 0.5 μg L−1, respectively. The method precision was evaluated by assessing intra- and interday precision at three different analyte concentrations, yielding values of 8.9% and 16.8%, respectively. Moreover, the method accuracy fell within the range of 90.9% to 107.5%. This proposed method offers a green and environmentally friendly sample preparation technique for conducting pharmacodynamic, pharmacokinetic, and therapeutic drug monitoring studies of Remdesivir in biological fluids. Importantly, this technique eliminates the need for external energy sources or the use of dispersive solvents, providing a more efficient and sustainable approach.

A-352 Investigation of the Immunochromatographic Method using 150 nm Gold Colloids (1)-Comparison of Different Types of Gold Colloids

Abstract Background Gold colloids, which have been extensively used in immunochromatography, are typically 40 nm in particle size. Recently, 150 nm gold colloidal nanoparticles, which are prepared by gold coating a silica nucleus up to a diameter of 150 nm, have attracted considerable attention. These nanoparticles enable high sensitivity in immunochromatography. The purpose of this study is to compare the antibodies labeled with 40 and 150 nm gold colloids using the physisorption and covalent bonding methods, which are applied to the immunochromatography method developed in our laboratory. Methods 1) For the physisorption method, 40 nm gold colloids (gold colloid AuH2, Morinaga Institute of Biochemistry) and 150 nm gold nanoshells (nanoComposix) were used to physically adsorb the antibody. The covalent gold conjugation kit (nanoComposix) was used to prepare 40 nm gold colloid-labeled antibodies by covalent bonding, and the high sensitivity gold conjugation kit was used to perform covalent bonding of the antibody and gold colloid after buffer displacement of the antibody.2) Anti-human albumin monoclonal antibody (abcam) was applied as the solid-phase antibody onto a nitrocellulose membrane (HF075, Merck Millipore) and dried. A human serum albumin sample (Fujifilm Wako Pure Chemicals) was diluted to a concentration of 1 mg/mL using phosphate-buffered saline (PBS). The sample was mixed with the gold colloid-labeled antibodies and a blocking solution (EZBlock Chemi, ATTO). Subsequently, 90 μL of the mixture was added dropwise and allowed to expand for 15 min before analysis. Results 1) Comparison of detection linesA red line was detected in the judgment zone for the 40 nm gold colloid, whereas a black line was detected in the judgment zone for the 150 nm gold colloid. The background of the detection area for the physisorption method was higher than that for the covalent bonding method. 2) Comparison of detection sensitivitiesUsing the physisorption method, the 40 nm gold colloid detected up to 10 ng/mL. In contrast, using the covalent bonding method, the 40 nm gold colloid detected up to 100 ng/mL. Using the physisorption method, the 150 nm gold colloid detected up to 3 ng/mL when tested at 100, 10, and 3 ng/mL. In contrast, using the covalent bonding method, the 150 nm gold colloid detected up to 3 ng/mL. Conclusion Currently, 40 nm gold colloids are extensively used as a labeling material in immunochromatography. However, the use of 150 nm gold colloids, which have better detection sensitivity, may increase sensitivity and lead to more accurate detection.

Triboelectric probes for investigating charge transfer at the colloid-solid interface

The charge transfer between the colloid and solid interface is a crucial factor for predicting colloid behavior and rational utilization of colloids. Despite its significance, analyzing the characteristics and subsequent effects of charge transfer at the colloid-solid interface remains challenging due to the complex multiphase nature of colloids. In this study, a liquid-solid triboelectric nanogenerator was used as a probe to detect the interfacial charge transfer during the contact electrification process of colloid-solid. The impact of colloid type, colloidal nanoparticle residue on the solid surface, and colloidal nanoparticle surface charge were investigated. The results indicate that in cases where the colloidal dispersion medium contains an excessive number of ions, ion adsorption dominates the interfacial charge transfer. The generation of hydrated protons after electron transfer between the colloid and solid leads to the deposition of colloidal nanoparticles on the solid surface, inhibiting charge transfer. When the dispersion medium contains fewer free ions and the colloidal nanoparticles possess a hydrophilic surface, the colloidal electric double layer significantly influences the interfacial charge transfer. The findings of this study provide valuable insights and open up new possibilities for further research in understanding the interactions between colloids and solids.

Influence of the Mechanochemical Modification of Humic Acids on the Formation of Colloids in Solution

The colloid-chemical properties of humic acids (HAs) were studied depending on the mechanochemicalmodification of their structure. An increase in the amount of acidic ionogenic groups and hydrophilicfragments in the composition of modified HAs facilitated a decrease in the excess energy of surfacemolecules. In an alkaline solution, two types of colloids characterized by a decrease in the energy of adsorption and the constant of adsorption equilibrium were formed as the concentration of HAs was increased.

Review of self-assembly of nanoparticles and its applications in the manufacturing of different types of colloids

An innovative approach that blends nanotechnology technologies with supramolecular chemistry can accelerate the creation of complex nanoparticle-based goods, self-assembly is used in the production of nanoscale self-assembled systems with desired properties with great versatility and potential. One of the most intriguing classes of material that can be constructed by self-assembly is colloids which is widely used in many areas, especially in the pharmaceutical and industry.

Diffusiophoresis of latex driven by anionic nanoparticles and their counterions

HypothesisDiffusiophoresis of colloidal latex particles has been reported for molecular anions and cations of comparable size. In the present study, this phenomenon is observed for two types of charged colloids acting as multivalent electrolyte: (i) anionic charge-stabilised silica nanoparticles or (ii) minimally-charged sterically-stabilised diblock copolymer nanoparticles. ExperimentsUsing a Hele-Shaw cell, a thin layer of relatively large latex particles is established within a sharp concentration gradient of nanoparticles by sequential filling with water, latex particles and nanoparticles. Asymmetric diffusion is observed, which provides strong evidence for diffusiophoresis. Quantification involves turbidity measurements from backlit images. FindingsThe latex particles diffuse across a concentration gradient of charged nanoparticles and the latex concentration front scales approximately with time1/2. Moreover, the latex particle flux is inversely proportional to the concentration of background salt, confirming electrostatically-driven motion. These observations are consistent with theory recently developed to account for diffusiophoretic motion driven by multivalent ions.

NIR-AIEgens nanospheres featuring high-fidelity dynamic lipid droplet targeting, expediting ferroptosis to annihilating tumor in hypoxia

Severe ferroptosis is a non-apoptotic iron-dependent cell death pathway, and extreme hypoxia and anomalous iron metabolism in tumors critically suppress the efficacy of ferroptosis therapy. Overcoming tumor hypoxia while facilitating ferroptosis is an extremely challenging task. Herein, the photosensitizer named BOTTQ with specific targeting of lipid droplet (LD) was synthesized by increasing the tail chain length of triphenylamine. The addition of alkoxy chains optimized the molecular structure and fostered inter-system crossing and type I reactive oxygen species (ROS) generation. Besides, BOTTQ yielded large amounts of type I ROS under light excitation oxidize efficiently polyunsaturated fatty acids in lipid monolayer of LD and contribute to the formation of ferroptosis substrate. Meanwhile, the generation of type I ROS accelerated the Fenton reaction, thus effectively boosting the occurrences of ferroptosis. Furthermore, the successful encapsulation of BOTTQ into DSPE-PEG-MAL material not only elevates the stable type of nanoparticle colloids, but the MAL moiety can deplete the functional thiols of glutathione in a mild environment, which leads to glutathione failure and facilitates ferroptosis. Thus tumor-specific ferroptosis-inducing strategy offers a universally applicable therapy with the capacity to enhance type I ROS production and effectively contain tumorigenesis.

Deciphering Lung Adenocarcinoma Heterogeneity: An Overview of Pathological and Clinical Features of Rare Subtypes.

Lung cancer is one of the most frequently diagnosed cancers worldwide and the leading cause of cancer-related death. The 2021 World Health Organization (WHO) classification provided a detailed and updated categorization of lung adenocarcinomas with a special focus on rare histological types, including enteric, fetal and colloid types, as well as not otherwise specified adenocarcinoma, overall accounting for about 5-10% of all cases. However, rare entities are nowadays difficult to diagnose in most centers, and evidence of optimal therapeutic management for these patients is still lacking. In recent years, increasing knowledge about the mutational profile of lung cancer, in addition to the spreading diffusion of next-generation sequencing (NGS) in different centers, have been helpful in the identification of rare variants of lung cancer. Hence, the hope is that several new drugs will be available in the near future to treat these rare lung tumors, such as in targeted therapy and immunotherapy, which are often used in clinical practice for several malignancies. The aim of this review is to summarize the current knowledge about the molecular pathology and clinical management of the most common rare adenocarcinoma subtypes in order to provide a concise and updated report that can drive clinicians' choices in their routine practice.

Solutions of rods and spheres: Predictions for the diffusion coefficient

The systems considered here are mixtures of neutral rods and spheres in solution, for which I aim to describe the rods’ diffusion coefficient. Several situations are studied according to the partial volume fractions and relative sizes between the two types of colloids. Using scaling analyses, I either obtain the translational or the rotational diffusion coefficient. Some of my predictions are compared with available experimental and numerical data, showing good agreement. The relevance of this work is to provide models that capture the main features concerning the diffusion of rods in mixed colloidal solutions and make contact with a much more intricate problem of diffusion in crowded media, such as the interior of the cytoplasm.

Perioperative colloids: From theory to practice.

Fluid administration is the cornerstone in hypovolemic patient's reanimation. Clinical guidelines restrict colloid administration favouring crystalloids. Currently, we don't know exactly which is the daily clinical practice during the perioperative period. The objective of this study is to describe perioperative use of colloids analysing possible reasons aiming to use them. Prospective, cross-section, national, multicentre observational study. Fluid Day sub-study. We enrolled all patient's older than 18 years old who underwent surgery during the 24 h of the 2-days study (February, 2019, 18th and 20th). We registered demographic data, comorbidities, anaesthetic and surgical procedure data, fluids administered, perioperative bleeding and monitoring type used during the perioperative period. A total of 5928 cases were analysed and 542 patients (9.1%) received any type of colloids, being hydroxiethyl-starch the most frequently used (5.1%). Patients receiving colloids suffered more longing surgery (150 [90-255] vs. 75 [45-120] min), were urgently operated (13.7 vs. 7.5%) and were more frequent classified as high risk (22 vs. 4.8%). Their recovery was mostly in critical care units (45.1 vs.15.8%). Patients with bleeding less than 500 ml received colloids in a percentage of 5.9 versus 45.9% when this figure was overcome. Patients who received colloids were anaemic more frequently: 29.4 vs. 16.3%. Colloids administration had a higher risk for transfusion (OR 15.7). Advanced monitoring also increased the risk for receiving colloids (OR 9.43). In our environment with routine clinical practice, colloids administration is limited and close linked to perioperative bleeding.

Active Colloids as Models, Materials, and Machines.

Active colloids use energy input at the particle level to propel persistent motion and direct dynamic assemblies. We consider three types of colloids animated by chemical reactions, time-varying magnetic fields, and electric currents. For each type, we review the basic propulsion mechanisms at the particle level and discuss their consequences for collective behaviors in particle ensembles. These microscopic systems provide useful experimental models of nonequilibrium many-body physics in which dissipative currents break time-reversal symmetry. Freed from the constraints of thermodynamic equilibrium, active colloids assemble to form materials that move, reconfigure, heal, and adapt. Colloidal machines based on engineered particles and their assemblies provide a basis for mobile robots with increasing levels of autonomy. This review provides a conceptual framework for understanding and applying active colloids to create material systems that mimic the functions of living matter. We highlight opportunities for chemical engineers to contribute to this growing field.

Migration risk of Escherichia coli O157:H7 in unsaturated porous media in response to different colloid types and compositions

The vadose zone is a critical zone for microbial entry into the subsurface environment, and various types of inorganic and organic colloids can affect the migration of pathogenic bacteria. In the study, we explored the migration behavior of Escherichia coli O157:H7 with humic acids (HA), iron oxides (Fe2O3) or their mixture, uncovering their migration mechanisms in the vadose zone. The effect of complex colloids on the physiological properties of E. coli O157:H7 was analyzed based on the measured particle size, zeta potential and contact angle. HA colloids significantly promoted the migration of E. coli O157:H7, where Fe2O3 was opposite. The migration mechanism of E. coli O157:H7 with HA and Fe2O3 is obviously different. Multiple colloids dominated by organic colloid will further highlight its promoting effect on E. coli O157:H7 under the guidance of electrostatic repulsion due to the influence of colloidal stability. Multiple colloids dominated by metallic colloid will inhibit the migration of E. coli O157:H7 under the control of capillary force due to the restriction of contact angle. The risk of secondary release of E. coli O157:H7 can be effectively reduced when the ratio of HA/Fe2O3 is ≥ 1. Combining this conclusion with the distribution characteristics of soil in China, an attempt was made to analyse the migration risk of E. coli O157:H7 on a national scale. In China, from north to south, the migration capacity of E. coli O157:H7 gradually decreased, and the risk of secondary release gradually increased. These results provide ideas for the subsequent study of the effect of other factors on the migration of pathogenic bacteria on a national scale and provide risk information about soil colloids for the construction of pathogen risk assessment model under comprehensive conditions in the future.