Liquid Beads Research Articles

Liquid metal-embedded magnetic hydrogel beads as novel adsorbents for malachite green removal

Malachite green (MG) is widely used in aquaculture as a parasiticide. It has generated much concern due to its carcinogenesis, mutagenesis, chromosomal fractures, teratogenicity, and respiratory toxicity. Effective methods for removing MG from water or other media are highly needed. Here, liquid metal (LM) is embedded into the magnetic hydrogel to create magnetic LM hydrogel beads with high adsorption capacity. The morphology and physical properties of the LM-embedded magnetic hydrogel beads are characterized using scanning electron microscopy, optical microscopy, and texture analysis methods. The adsorption efficiency of malachite green was assessed using spectrophotometric analysis at a wavelength of 623 nm. The hardness of these hydrogel beads reached a maximum of 4610 g, and its adsorption capacity reached 10 mg/g. Under the optimal condition, 0.05 %wt LM embedded magnetic hydrogel could remove 100 % of MG. This highly efficient magnetic adsorbent for dye removal has considerable potential for rapidly separating toxic contaminants from aquatic animal tissues, providing a cost-effective and straightforward solution to reduce dye pollution in aquatic environments and food products.

Microfluidic Encapsulation of DNAs in Liquid Beads for Digital Loop‐Mediated Isothermal Amplification

Digital nucleic acid analysis has emerged as a prominent tool for the detection and absolute quantification of diverse pathogens. Digital loop‐mediated isothermal amplification (dLAMP) offers highly sensitive, specific, time‐efficient, and cost‐effective nucleic acid amplification. However, existing dLAMP techniques face challenges such as droplet merging, reliance on surfactants, restricted partition capacities, and the potential for sample loss during heating. Herein, these issues are addressed by introducing liquid beads for sample partitioning. Compared to microwells, our approach overcomes the limitations of chamber dimensions, enabling the analysis of an unlimited number of digitized targets. Furthermore, our novel approach effectively addresses sample loss and merging during thermal processing and eliminates the need for surfactants. Accurate and reproducible the quantitative detection of the gene cluster XALB1 of leaf scald disease is conducted using dLAMP based on liquid beads to verify its availability. The results demonstrate a high correlation between target concentration and positive signals, indicating the robust performance of our technique. A comparative analysis is then performed between dLAMP using liquid beads and using single droplets. Benchmarking these two techniques highlights the effectiveness of our innovative technique in overcoming existing challenges in dLAMP.

Laser solid-phase synthesis of graphene shell-encapsulated high-entropy alloy nanoparticles

Rapid synthesis of high-entropy alloy nanoparticles (HEA NPs) offers new opportunities to develop functional materials in widespread applications. Although some methods have successfully produced HEA NPs, these methods generally require rigorous conditions such as high pressure, high temperature, restricted atmosphere, and limited substrates, which impede practical viability. In this work, we report laser solid-phase synthesis of CrMnFeCoNi nanoparticles by laser irradiation of mixed metal precursors on a laser-induced graphene (LIG) support with a 3D porous structure. The CrMnFeCoNi nanoparticles are embraced by several graphene layers, forming graphene shell-encapsulated HEA nanoparticles. The mechanisms of the laser solid-phase synthesis of HEA NPs on LIG supports are investigated through theoretical simulation and experimental observations, in consideration of mixed metal precursor adsorption, thermal decomposition, reduction through electrons from laser-induced thermionic emission, and liquid beads splitting. The production rate reaches up to 30 g/h under the current laser setup. The laser-synthesized graphene shell-encapsulated CrMnFeCoNi NPs loaded on LIG-coated carbon paper are used directly as 3D binder-free integrated electrodes and exhibited excellent electrocatalytic activity towards oxygen evolution reaction with an overpotential of 293 mV at the current density of 10 mA/cm2 and exceptional stability over 428 h in alkaline media, outperforming the commercial RuO2 catalyst and the relevant catalysts reported by other methods. This work also demonstrates the versatility of this technique through the successful synthesis of CrMnFeCoNi oxide, sulfide, and phosphide nanoparticles.

Micro container made of levitated liquid bead

Liquid bead, an emerging digital microfluidic platform offers a wide range of applications in research and industry. Making liquid beads using acoustic levitation technology allows for the fabrication of micro container. Extensive insight into levitated liquid beads is essential for determining their performance. Firstly, this paper unfolds the unique interface of the levitated liquid bead, which has thin membrane of shell material on top and thus serves as a micro container. Next, we characterised the puncture toughness of liquid beads to assess the capability of releasing the liquid content. Liquid bead with larger corresponding shell volume and lower core volume recorded the highest resistance against needle penetration. Finally, we observed the thermal behaviour of liquid beads at elevated temperature. The liquid beads showed no morphological change over 10-minutes period at 50 °C. At 65 °C, liquid bead exceeded the critical temperature threshold, which resulted in breaking the thin membrane and releasing the liquid from the core.

Calcium Alginate Core–Shell Liquid Beads Encapsulated with Microalgae for Wastewater Treatment

Calcium Alginate Core–Shell Liquid Beads Encapsulated with Microalgae for Wastewater Treatment

Synthesis and active manipulation of magnetic liquid beads

We report the fabrication and characterisation of magnetic liquid beads with a solid magnetic shell and liquid core using microfluidic techniques. The liquid beads consist of a fluorinated oil core and a polymer shell with magnetite particles. The beads are generated in a flow-focusing polydimethylsiloxane (PDMS) device and cured by photo polymerisation. We investigated the response of the liquid beads to an external magnetic field by characterising their motion towards a permanent magnet. Magnetic sorting of liquid beads in a channel was achieved with 90% efficiency. The results show that the liquid beads can be controlled magnetically and have potential applications in digital microfluidics including nucleic acid amplification, drug delivery, cell culture, sensing, and tissue engineering. The present paper also discusses the magnetophoretic behaviour of the liquid bead by varying its mass and magnetite concentration in the shell. We also demonstrated the two-dimensional self-assembly of magnetic liquid beads for potential use in digital polymerase chain reaction and digital loop mediated isothermal amplification.Graphical abstract

Calcium Alginate Core–Shell Liquid Beads Encapsulated with Microalgae for Wastewater Treatment

Liquid beads are core–shell particles with a liquid core and a solid shell. Calcium alginate liquid beads have been emerging as a promising platform for cell encapsulation. These beads have demonstrated their capability of encapsulating and culturing a wide range of human cells for tissue engineering. However, a significant research gap remains in the application of alginate liquid beads for encapsulating photosynthetic microorganisms. Herein, fast‐growing microalgae strain Chlorella vulgaris is encapsulated into calcium alginate liquid beads to facilitate the removal of nutrients from wastewater, minimizing the risk of eutrophication. Liquid bead‐microalgae systems are prepared, using different calcium ion concentrations as crosslinking ions. It has been thoroughly characterized for their morphologies, cell growth patterns, nutrient removal capabilities, and overall stability throughout the wastewater treatment process, with upflow anaerobic sludge blanket effluent as the wastewater model. The results indicate that the liquid bead‐microalgae system with the highest calcium ion concentration (5%) performs more efficiently, exhibiting a well‐formed crosslinking structure, leading to rapid cell growth with the highest cell density and the most effective removal of nutrients. The findings from this study provide valuable insights for future optimization and upscaling efforts in wastewater treatment systems based on calcium alginate liquid beads.

Liquid–Liquid-Printed Graphitic Carbon Nitride-Embedded Porous Poly(ionic liquid) Beads as Highly Active Reusable Heterogenous Photocatalysts

Liquid–Liquid-Printed Graphitic Carbon Nitride-Embedded Porous Poly(ionic liquid) Beads as Highly Active Reusable Heterogenous Photocatalysts

Highly Stretchable and Fluorescent Visualizable Thermoplastic Polyurethane/Tetraphenylethylene Plied Yarn Strain Sensor with Heterogeneous and Cracked Structure for Human Health Monitoring.

Smart wearable technology has been more and more widely used in monitoring and prewarning of human health and safety, while flexible yarn-based strain sensors have attracted extensive research interest due to their ability to withstand greater external strain and their significant application potential in real-time monitoring of human motion and health signals. Although several strain sensors based on yarn structures have been reported, it remains challenging to strike a balance between high sensitivity and wide strain ranges. At the same time, visual signal sensing is expected to be used in strain sensors thanks to its intuitiveness. In this work, thermoplastic polyurethane (TPU) and tetraphenylethylene (TPE) were wet-spun to fabricate flexible fluorescent fibers used as the substrate of the sensor, followed by the drop addition of polydimethylsiloxane (PDMS) beads and curing to produce a heterogeneous structure, which were further twisted into a plied yarn. Finally, a visualizable flexible yarn strain sensor based on solidified liquid beads and crack structure was obtained by loading polydopamine (PDA) and polypyrrole (PPy) in situ. The sensor exhibited high sensitivity (the GF value was 58.9 at the strain range of 143-184%), a wide working strain range (0-184%), a low monitoring limit (<0.1%), a fast response (58.82 ms), reliable responses at different frequencies, and excellent cycle durability (over 2000 cycles). At the same time, the yarn strain sensor also had excellent photothermal characteristics and a fluorescence crack visualization effect. These attractive advantages enabled yarn strain sensors to accurately monitor various human activities, showing great application potential in health monitoring, personalized medical diagnosis, and other aspects.

Improving the survival of probiotics via in situ re-culture in calcium alginate gel beads

Despite the fact that probiotics have several health benefits for the host, low-pH gastric acid and bile salts threaten their survival. Here, a simple in situ re-culture approach using calcium alginate gel beads to improve the survival of probiotics was reported. After re-culture, Lacticaseibacillus rhamnosus GG (LGG) in both liquid and solid core gel beads (LCGB and SCGB) exhibited 100% gastric acid resistance, while the bile salt resistance varied from 59.38% to 92.39%. LGG in LCGB generally showed higher bile salt resistance than SCGB, and the resistance would be further improved with high initial bacterial concentration due to more extracellular polymer secretion. Besides, the re-cultured LGG in beads exhibited survival of 95.02%–96.05% in calcium-supplemented MRS broth within 6 weeks at 4 °C. Importantly, this storage did not threaten the aforementioned resistance of re-cultured LGG. The mechanism of LGG damage by gastric acid in LCGB includes 8 pathways, among which, 2 pathways including propanoate metabolism, phenylalanine, tyrosine and tryptophan biosynthesis are responsible for the improved resistance of re-cultured LGG. The unique re-culture strategy provides a powerful platform for microbial agents to smoothly enter the gut to serve host health.

Influence of wind on a viscous liquid film flowing down a thread

A liquid film flowing down a fiber or thread is well known to destabilize into an axisymmetric bead-like pattern in stagnant air. We demonstrate experimentally how side wind affects such a film flow. Our results show that side wind increases the descent speed of the liquid beads, highlighting that the film flow regime can be changed by controlling the magnitude of the wind speed.

Microfluidic encapsulation of DNAs in liquid beads for digital PCR application.

Droplet-based microfluidics and digital polymerase chain reaction (PCR) hold significant promise for accurately detecting and quantifying pathogens. However, existing droplet-based digital PCR (ddPCR) applications have been relying exclusively on single emulsion droplets. Single emulsion droplets may not be suitable for applications such as identifying the source and pathways of water contamination where the templates must be protected against harsh environmental conditions. In this study, we developed a core-shell particle to serve as a protective framework for DNAs, with potential applications in digital PCR. We employed a high-throughput and facile flow-focusing microfluidic device to generate liquid beads, core-shell particles with liquid cores, which provided precise control over process parameters and consequently particle characteristics. Notably, the interfacial interaction between the core and shell liquids could be adjusted without adding surfactants to either phase. As maintaining stability is essential for ensuring the accuracy of digital PCR (dPCR), we investigated parameters that affect the stability of core-shell droplets, including surfactants in the continuous phase and core density. As a proof of concept, we encapsulated a series of human faecal DNA samples in the core-shell droplets and the subsequent liquid beads. The core-shell particles ensure contamination-free encapsulation of DNA in the core. The volume of the core droplets containing the PCR mixture is only 0.12 nL. Our experimental results indicate that the liquid beads formulated using our technique can amplify the encapsulated DNA and be used for digital PCR without interfering with the fluorescence signal. We successfully demonstrated the ability to detect and quantify DNA under varying concentrations. These findings provide new insights and a step change in digital PCR that could benefit various applications, including the detection and tracking of environmental pollution.

Studying Murine Small Bowel Mechanosensing of Luminal Particulates.

Gastrointestinal (GI) motility is critical for normal digestion and absorption. In the small bowel, which absorbs nutrients, motility optimizes digestion and absorption. For this reason, some of the motility patterns in the small bowel include segmentation for mixing of luminal contents and peristalsis for their propulsion. Physical properties of luminal contents modulate the patterns of small bowel motility. The mechanical stimulation of GI mechanosensory circuits by transiting luminal contents and underlying gut motility initiate and modulate complex GI motor patterns. Yet, the mechanosensory mechanisms that drive this process remain poorly understood. This is primarily due to a lack of tools to dissect how the small bowel handles materials of different physical properties. To study how the small bowel handles particulates of varying sizes, we have modified an established in vivo method to determine small bowel transit. We gavage live mice with fluorescent liquid or tiny fluorescent beads. After 30 minutes, we dissect out the bowels to image the distribution of fluorescent contents across the entirety of the GI tract. In addition to high-resolution measurements of the geometric center, we use variable size binning and spectral analysis to determine how different materials affect small bowel transit. We have explored how a recently discovered "gut touch" mechanism affects small bowel motility using this approach.

The surfactant-ionic liquid bi-functionalization of chitosan beads for their adsorption performance improvement toward Tartrazine.

In this study, the ionic liquid (Aliquat-336) and anionic surfactant (cetyltrimethylammonium bromide, CTAB) bi-functionalized chitosan beads were prepared and characterised using different techniques, including FTIR, XRD, SEM, EDS and BET surface area analysis. The characteristic analysis confirmed the successful conjugation of chitosan beads with both surfactant and ionic liquid. The novel fabricated beads (CS-CTAB-AL) were efficiently employed, as a high-performance adsorbent, for the removal of Tartrazine (TZ), an anionic food dye, from polluted water. The optimum adsorption of TZ onto the CS-CTAB-AL was found at 2gL-1 of adsorbent in the wide pH range of 4-11, whereas just 45min was required to reach more than 90% adsorption efficiency in the studied conditions. Also, the adsorption and kinetic studies showed that the experimental data well fitted the pseudo-first-order kinetic model and the Langmuir isotherm model. The maximum adsorption capacity of prepared beads was found to be 45.95mgg-1 at 45°C. The adsorption properties of enabling CS-CTAB-AL conjugation introduced a new type of adsorbents, exploited the combination of ionic liquid and surfactant capabilities for wastewater treatment.

Autonomous Incident Detection on Spectrometers Using Deep Convolutional Models.

This paper focuses on improving the performance of scientific instrumentation that uses glass spray chambers for sample introduction, such as spectrometers, which are widely used in analytical chemistry, by detecting incidents using deep convolutional models. The performance of these instruments can be affected by the quality of the introduction of the sample into the spray chamber. Among the indicators of poor quality sample introduction are two primary incidents: The formation of liquid beads on the surface of the spray chamber, and flooding at the bottom of the spray chamber. Detecting such events autonomously as they occur can assist with improving the overall operational accuracy and efficacy of the chemical analysis, and avoid severe incidents such as malfunction and instrument damage. In contrast to objects commonly seen in the real world, beading and flooding detection are more challenging since they are of significantly small size and transparent. Furthermore, the non-rigid property increases the difficulty of the detection of these incidents, as such that existing deep-learning-based object detection frameworks are prone to fail for this task. There is no former work that uses computer vision to detect these incidents in the chemistry industry. In this work, we propose two frameworks for the detection task of these two incidents, which not only leverage the modern deep learning architectures but also integrate with expert knowledge of the problems. Specifically, the proposed networks first localize the regions of interest where the incidents are most likely generated and then refine these incident outputs. The use of data augmentation and synthesis, and choice of negative sampling in training, allows for a large increase in accuracy while remaining a real-time system for inference. In the data collected from our laboratory, our method surpasses widely used object detection baselines and can correctly detect 95% of the beads and 98% of the flooding. At the same time, out method can process four frames per second and is able to be implemented in real time.

Isolation of Circulating Biomarkers for Liquid Biopsy using Immunoaffinity‐Based Stimuli‐Responsive Hybrid Hydrogel Beads

AbstractThis work presents chemically stable and biodegradable hydrogel beads for the isolation of circulating tumor cells (CTCs) and circulating exosomes in liquid biopsy. The liquid biopsy hydrogel beads (LBbeads) consisting of alginate and poly(vinyl alcohol) hydrogels show both chemical stability and stimuli‐degradable characteristics. Unlike single‐component hydrogels, this hybrid form is not easily degraded by buffers or cell culture media while its degradable characteristic remains; thus, it is useful in bio‐applications requiring multi‐step processes with various reagents and lengthy incubation periods. We applied our platform to clinical samples for isolating two promising circulating biomarkers for a liquid biopsy, CTCs and exosomes, by conjugating the hydrogel surface with anti‐EpCAM and anti‐CD63 antibodies, respectively, thus achieving 37.4 CTCs and comparable amount of exosome recovery per 1 milliliter of blood. The results show easy device‐free isolation and retrieval of CTCs and exosomes, with recovered circulating biomarkers successfully analyzed by western blot analysis and fluorescence microscopy. We believe that this simple and versatile platform enables us to isolate prominent circulating biomarkers for clinical use in cancer diagnosis.

Cell Migration Driven by Self-Generated Integrin Ligand Gradient on Ligand-Labile Surfaces

Integrin-ligand interaction mediates the adhesion and migration of many metazoan cells. Here, we report a unique mode of cell migration elicited by the lability of integrin ligands. We found that stationary cells spontaneously turn migratory on substrates where integrin ligands are subject to depletion by cellular force. Using TGT, a rupturable molecular linker, we quantitatively tuned the rate of ligand rupture by cellular force and tested platelets (anucleate cells), CHO-K1 cells (nucleated cells), and other cell types on TGT surfaces. These originally stationary cells readily turn motile on the uniform TGT surface, and their motility is correlated with the ligand depletion rate caused by cells. We named this new migration mode ligand-depleting (LD) migration. Through both experiments and simulations, we revealed the biophysical mechanism of LD migration. We found that the cells create and maintain a gradient of ligand surface density underneath the cell body by constantly rupturing local ligands, and the gradient in turn drives and guides cell migration. This is reminiscent of the phenomenon that some liquid droplets or solid beads can spontaneously move on homogeneous surfaces by chemically forming and maintaining a local gradient of surface energy. Here, we showed that cells, as living systems, can harness a similar mechanism to migrate. LD migration is beneficial for cells to maintain adhesion on ligand-labile surfaces, and might also play a role in the migration of cancer cells, immune cells, and platelets that deplete adhesive ligands of the matrix.

Study on liquid core barberry (Berberis vulgaris) hydrogel beads based on calcium alginate: Effect of storage on physical and chemical characterizations

Production of barberry hydrogel beads containing suspended pulp was investigated based on reverse spherification method. Beads with different concentration of sodium alginate (0.5%, 0.8%, and 1% w/v) and calcium lactate (1%, 1.67%, and 2.2% w/v) were prepared. Total phenolic content (TPC), antioxidant capacity, membrane thickness, microstructure, hardness, and thermal properties of beads were evaluated at the time of production and after two months of storage. Textural studies indicated that an increase in sodium alginate concentration, improved hardness (from 67.2 to 207 g) of liquid hydrogel beads and reduced the destruction of antioxidants and total phenolic contents during storage. Calcium lactate concentrations had an adverse effect on hardness of hydrogels. Evaluation of micrographs confirmed a significant difference between the network structures of hydrogels containing various concentrations of calcium ions. TPC contents of the sample containing the highest concentration of sodium alginate were higher than beads containing 0.5% and 0.8% sodium alginate. Practical applications As a result of this paper, we will be able to fabricate a method to produce hydrogel beads filled with barberry syrup. This product can be easily consumed as a nutritional snack by people of different ages. This product will be interesting for children due to its unique mouthfeel as the liquor in the beads bursts into the mouth with teeth pressure. Protection of the nutritional properties of herbal extracts using reverse spherification method will be possible as a result of our developed method, which can be applied for different products in the future.

Локализация и метаболическая активность мезенхимальных стромальных клеток в альгинатных микросферах с твердым и жидким ядром

Локализация и метаболическая активность мезенхимальных стромальных клеток в альгинатных микросферах с твердым и жидким ядром

Water vapor capturing using an array of traveling liquid beads for desalination and water treatment.

Growing concern over the scarcity of freshwater motivates the development of compact and economic vapor capture methods for distributed thermal desalination or harvesting of water. We report a study of water vapor condensation on cold liquid beads traveling down a massive array of vertical cotton threads that act as pseudo-superhydrophilic surfaces. These liquid beads form through intrinsic flow instability and offer localized high-curvature surfaces that enhance vapor diffusion toward the liquid surface, a critical rate-limiting step. As the liquid flow rate increases, the bead spacing decreases, whereas the bead size and speed stay nearly constant. The resulting increase in the spatial bead density leads to mass transfer conductances and hence condensation rates per volume that are almost three times higher than the best reported values. Parallel and contiguous gas flow paths also result in a substantial reduction in gas pressure drop and hence electric fan power consumption.