Hydrophobic Agents Research Articles

Research on the performance of foamed concrete based on superhydrophobic bulk modification

Foamed concrete is a kind of lightweight insulation material formed by the uniform mixture of foam and cement slurry. The superhydrophobic bulk modification of foamed concrete can reduce its high water absorption and prolong its service life. In this paper, the compatibility of three hydrophobic agents named polydimethylsiloxane (PDMS), isoctyltriethoxysilane (ICTS) and SBT®-TIA with foams was studied, and the reasons of incompatibility were revealed. Then, the superhydrophobic bulk foamed concrete system was constructed by physical foaming method, adding polydimethylsiloxane (PDMS), calcium stearate (CS), nano-silica (NS) and covering the surface of the specimen with 200-mesh wire mesh. The results show that the maximum contact angles of the meshed surface and the internal polished surface of superhydrophobic foamed concrete were 162.7° and 153.5°, respectively. At the same time, the water absorption rate of the modified specimen was significantly reduced, and the reduction rate was up to 90 %. In addition, the deterioration degree of thermal insulation performance after soaking and the dry shrinkage rate were significantly reduced compared with ordinary foamed concrete. Scanning electron microscopy (SEM) revealed that increasing the multi-scale roughness could improve the hydrophobic properties of foamed concrete. Fourier infrared spectroscopy (FT-IR) also confirmed that low surface energy groups such as -CH2 and -CH3 in PDMS bonded to the cement hydration products, indicating the successful preparation of superhydrophobic bulk foamed concrete.

Biocompatible fluorescent carbon nanoparticles as nanocarriers for targeted delivery of tamoxifen for regression of Breast carcinoma

Breast cancer (BC) is the most common malignancy among females worldwide, and its high metastasis rates are the leading cause of death just after lung cancer. Currently, tamoxifen (TAM) is a hydrophobic anticancer agent and a selective estrogen modulator (SERM), approved by the FDA that has shown potential anticancer activity against BC, but the non-targeted delivery has serious side effects that limit its ubiquitous utility. Therefore, releasing anti-cancer drugs precisely to the tumor site can improve efficacy and reduce the side effects on the body. Nanotechnology has emerged as one of the most important strategies to solve the issue of overdose TAM toxicity, owing to the ability of nano-enabled formulations to deliver desirable quantity of TAM to cancer cells over a longer period of time. In view of this, use of fluorescent carbon nanoparticles in targeted drug delivery holds novel promise for improving the efficacy, safety, and specificity of TAM therapy. Here, we synthesized biocompatible carbon nanoparticles (CNPs) using chitosan molecules without any toxic surface passivating agent. Synthesized CNPs exhibit good water dispersibility and emit intense blue fluorescence upon excitation (360 nm source). The surface of the CNPs has been functionalized with folate using click chemistry to improve the targeted drug uptake by the malignant cell. The pH difference between cancer and normal cells was successfully exploited to trigger TAM release at the target site. After six hours of incubation, CNPs released ∼ 74 % of the TAM drug in acidic pH. In vitro, studies have also demonstrated that after treatment with the synthesized CNPs, significant inhibition of the tumor growth could be achieved.

Comparison of physicochemical properties and digestion behaviors of O/W emulsion stabilized by OSA/DDSA-modified high resistant starch

Emulsions stabilized by normal starch-based emulsifier could be easily digested for fat absorption. In this study, a novel design of resistant starch-based emulsifier (RSE) is expected to be a promising strategy in reducing fat digestibility. Waxy corn starch (WCS) was used to prepare RS by pullulanase debranching, and then RS was esterified with different hydrophobic agents of octenyl succinic anhydride (OSA) and dodecenyl succinate anhydride (DDSA) to prepare OSA/DDAS modified RSE (OSA-R and DDSA-R). The structure and emulsification properties of OSA-R and DDSA-R were comprehensively investigated. The results showed that RS content of WCS was increased from 0.17% to 35.52% by pullulanase debranching and then RS contents of OSA-R (37.53%) and DDSA-R (42.18%) could be further increased by OSA/DDSA modifications. Moreover, both OSA-R and DDSA-R stabilized emulsions were stable under neutral and alkaline conditions and were of good quality within 10 days of storage at 4 °C. Compared with OSA-R stabilized emulsion, DDSA-R stabilized emulsion had higher acid stability, CaCl2 stability and storage stability. Furthermore, in vitro digestion study demonstrated that both OSA-R and DDSA-R stabilized emulsions exhibited strong resistance against digestion. In conclusion, two high resistant starch-based emulsifiers obtained by OSA/DDAS modifications could be used for stabilizing oil-in-water emulsions, which provide important references for the selection of RSE esterification agents and the application of RS in food industry.

Multifunctional polyester-cotton fabrics with excellent flame retardancy, superhydrophobicity, antibacterial property and UV resistance

In this study, multifunctional polyester-cotton fabrics (PTCO) were constructed by gradually assembling polyethyleneimine phenyl phosphonate (POI) and different hydrophobic agents, respectively. The effect of different hydrophobic agents including tetraethyl orthosilicate, perfluorooctyltriethoxysilane (PFDTES), and hexadecyltrimethoxysilane on the thermal stability, flame retardancy, hydrophobic property, UV resistance and antibacterial property of PTCO/POI was investigated in detail. PTCO/POI-SiF had better flame retardancy due to the flame-retardant effect of PFDTES and POI, and the limiting oxygen index increased from 29.8 % to 31.2 %. The thermal oxidation stability of PTCO/POI-SiH and PTCO/POI-SiF was significantly improved in high temperatures, and the char residues at 700 °C were increased from 4.1 % to 7.6 % and 7.4 %. And PTCO/POI-SiH and PTCO/POI-SiF had excellent superhydrophobic properties with water contact angles of 151° and 162° and sliding angles of 4° and 3°. The ultraviolet protection factors of them were increased to 56.9 and 63.3, respectively, which had a good UV resistance. And both PTCO/POI-SiH and PTCO/POI-SiF had excellent antibacterial effects for E. coli and S. aureus. The breaking force, whiteness and moisture permeability of the finished fabrics had not been changed. Therefore, it is believed that PTCO/POI-SiH and PTCO/POI-SiF are promising for application in multifunctional fabrics.

Mussel-inspired fabrication of nonwovens using fluoride-free profiled fibers for directional water transport

Fabrics with directional water transport performance have attracted considerable attention in daily life. They are in high demand, owing to their ability to transport sweat away from the skin to improve personal comfort. However, the fabrication of such materials has still remained a critical task. This article reports a nonwoven with the directional water transport function, achieved using a synergistic combination of a microstructure and a wettability gradient. The three-step fabrication strategy involves needling bonding of Y cross-section polyamide fiber webs with two needling densities (30 and 190 needle/cm2), followed by single-sided spraying of polydopamine–silicon carbide powder–polyethyleneimine dispersion and a fluoride-free hydrophobic agent. Using fiber webs with different needling densities endows the nonwoven fabric with a differential capillary effect, enhancing the directional water transport property. The unique microstructure achieves the directional water transport property by improving permeability at lower needling densities and hindering transport through a denser needling density in the reverse direction. At the same time, the wetting gradient effect promotes water transfer from the hydrophobic surface to the hydrophilic surface. The successful preparation of these interesting directional water transport materials offers new insights into the role of fibrous materials, the needling density of nonwovens, and the development of highly comfortable moisture-wicking textiles.

Assessment of the properties of mortars made of sorel cement

The purpose of laboratory tests was to determine the effect of sodium silicate and selected hydrophobic agents on the basic physical parameters and freeze-thaw durability of mortars made with Sorel cement in variable proportions. In order to determine the mortars’ parameters, samples of the dimensions of 4x4x16 cm and boards of the diameters of 1x4x16 cm were prepared. Parameters such as water absorption, capillary absorption, compressive and flexural strength and frost resistance were tested. Mortar supplemented with sodium silicate in the quantity of 2.6% of all components demonstrated the best properties. None of the other hydrophobic agents that were used to mitigate the negative effects of water on Sorel cement mortars demonstrated such positive properties. Flexural strength tests of all mortar batches, performed on cuboid samples and boards of the thickness of 1 cm, demonstrated a similar improvement in strength. The lowest value of compressive strength was recorded for the reference batch at 46.6 MPa, whereas the highest value was recorded for the second batch containing sodium silicate, at 49.8 MPa. During the testing of frost resistance, the lowest reduction of compressive and flexural strength was recorded for the reference mortar and for mortar with sodium silicate. All mortars were varied in the MgO/MgCl2 ratio and the total amount of water, the observed effects may be caused by other variables. However it is possible to notice the positive effect of selected hydrophobic agents.

Synthesis strategies, regeneration, cost analysis, challenges and future prospects of bacterial cellulose-based aerogels for water treatment: A review

Clean water is an integral part of industries, agricultural activities and human life, but water contamination by toxic dyes, heavy metals, and oil spills is increasingly serious in the world. Aerogels with unique properties such as highly porous and extremely low density, tunable surface modification, excellent reusability, and thermal stability can contribute to addressing these issues. Thanks to high purity, biocompatibility and biodegradability, bacterial cellulose can be an ideal precursor source to produce aerogels. Here, we review the modification, regeneration, and applications of bacterial cellulose-based aerogels for water treatment. The modification of bacterial cellulose-based aerogels undergoes coating of hydrophobic agents, carbonization, and incorporation with other materials, e.g., ZIF-67, graphene oxide, nanoparticles, polyaniline. We emphasized features of modified aerogels on porosity, hydrophobicity, density, surface chemistry, and regeneration. Although major limits are relevant to the use of toxic coating agents, difficulty in bacterial culture, and production cost, the bacterial cellulose aerogels can obtain high performance for water treatment, particularly, catastrophic oil spills.

The effect of PEGylation components on drug release behavior of targeted reduced graphene oxide based drug delivery system

Reduced graphene oxide (rGO) is a restored, defect-free version of graphene oxide (GO) with regained graphene-like properties but encounters challenges in biomedical applications due to its low solubility. Especially for drug release applications, rGO’s stronger π-π interaction of rGO compared to GO leads to low release, often demanding novel approaches for enhancement. The recently developed PEGylation method utilizes a copolymer with tunable PEG chain length and density for the PEGylation of GO simultaneously reduced to rGO, resulting in water-dispersible and biocompatible rGO-based nanoplatforms. This copolymer integrates functional monomers and enhances treatment options. Herein, we investigated how these PEGylation components and their incorporation order impact rGO’s drug release behavior. A series of copolymers, (P(PEGMA-co-AzPMA-co-MMA-co-PMA), with different PEG brushes and azide groups, were synthesized via atom transfer radical polymerization. We explored the impact of ionic azide groups on drug release by comparing the azide-containing and azide-capped copolymers. Moreover, copolymers containing 500 or 2000 Da PEG brushes were compared to assess their role as a coating layer or diffusion barrier on drug release. Doxorubicin, a hydrophobic anticancer agent, was loaded onto the rGO surface before or after peptide-based targeting agent (EPPT1) conjugation. The results showed that the drug release behavior of 500 or 2000 Da PEG brushes containing rGO surfaces are different due to the density of PEG coating which makes the effect of azide groups not always visible. Incorporating the targeting peptide before drug loading was found to be optimal. The pH-dependent release profiles revealed 49 % and 44 % release from the rGO surface for the shorter and longer PEG brushes, respectively. Tuning the PEGylation components may further influence the release behavior.

Lysine and citric acid based pegylated polymeric dendritic nano drug delivery carrier and their bioactivity evaluation

The main objective of this work is to synthesize multifunctional nanodendritic structural molecules that can effectively encapsulate hydrophilic as well as hydrophobic therapeutic agents. Four different types of fourth-generation lysine-citric acid based dendrimer have been synthesized in this work: PE-MC-Lys-CA-PEG, TMP-MC-Lys-CA-PEG, PE-MS-Lys-CA-PEG, and TMP-MS-Lys-CA-PEG. The antibacterial drug cefotaxime (CFTX) was further conjugated to these dendrimers. The dendrimer and drug-dendrimer conjugate structures were characterized with the help of FTIR,1H-NMR, and 13C-NMR spectroscopy. Zeta sizer, AFM, and HR-TEM techniques were used to investigate the particle size, surface topography, and structural characteristics of drug-dendrimer conjugates. In vitro drug release was then investigated using dialysis method. Various kinetic drug release models were examined to evaluate the type of kinetic drug release mechanism of the formulations. Cytotoxicity study revealed that the dendrimers encapsulated with CFTX exhibited 2-3% toxicity against healthy epithelial cells, indicating their safe use. Plain dendrimers show 10-15% hemolytic toxicity against red blood cells (RBC), and the toxicity was reduced to 2-3% when CFTX was conjugated to the same dendrimers. The 3rd and 4th generation synthesized drug-dendrimer conjugates exhibit a significantly effective zone of inhibition (ZOI) against both Gram-positive and Gram-negative bacteria. For Gram-positive bacteria, the lower concentration of 0.1 mg/mL showed more than 98% inhibition of drug-dendrimer conjugate samples against B. subtilis and more than 50% inhibition against S. aureus using 0.2 mg/mL, respectively. Moreover, samples with concentrations of 0.5 and 1.0 mg/mL exhibited more than 50% inhibition against S. typhimurium and E. coli, respectively.

Hybrid Nanogel Drug Delivery Systems: Transforming the Tumor Microenvironment through Tumor Tissue Editing.

The future of drug delivery offers immense potential for the creation of nanoplatforms based on nanogels. Nanogels present a significant possibility for pharmaceutical advancements because of their excellent stability and effective drug-loading capability for both hydrophobic and hydrophilic agents. As multifunctional systems, composite nanogels demonstrate the capacity to carry genes, drugs, and diagnostic agents while offering a perfect platform for theranostic multimodal applications. Nanogels can achieve diverse responsiveness and enable the stimuli-responsive release of chemo-/immunotherapy drugs and thus reprogramming cells within the TME in order to inhibit tumor proliferation, progression, and metastasis. In order to achieve active targeting and boost drug accumulation at target sites, particular ligands can be added to nanogels to improve the therapeutic outcomes and enhance the precision of cancer therapy. Modern "immune-specific" nanogels also have extra sophisticated tumor tissue-editing properties. Consequently, the introduction of a multifunctional nanogel-based drug delivery system improves the targeted distribution of immunotherapy drugs and combinational therapeutic treatments, thereby increasing the effectiveness of tumor therapy.

Functionalization of aerosil, titanium dioxide and diatomaceous earth powders by wetting with a low surface energy agent, and study of their properties

The conditions for functionalization of micro- and nanopowders of aerosil, titanium dioxide and diatomaceous earth by wetting them with a liquid hydrophobic agent (tetraethoxysilane) and giving them fobno/philic properties are investigated. Using infrared spectroscopy, derivatography, scanning electron microscopy, and ξ-metry, the mechanism of tetraethoxysilane interaction with the surface of these powders and their morphology were studied. All powders thus modified are characterized by a non-homogeneous distribution of particles with different aggregation levels: predominantly micrometer-sized particle population (diatomaceous earth), micrometer-sized formation combined with nanoclusters (aerosil, titanium dioxide). Diluted suspensions of functionalized powders in fluorinated varnish were used for hydrophobization of glass, aluminum, and steel surfaces. The highest value of the water wetting edge angle (156°) was observed for aluminum coatings obtained using a composition containing functionalized aerosil.

Bead-Containing Superhydrophobic Nanofiber Membrane for Membrane Distillation.

This study introduces an innovative approach to enhancing membrane distillation (MD) performance by developing bead-containing superhydrophobic sulfonated polyethersulfone (SPES) nanofibers with S-MWCNTs. By leveraging SPES's inherent hydrophobicity and thermal stability, combined with a nanostructured fibrous configuration, we engineered beads designed to optimize the MD process for water purification applications. Here, oxidized hydrophobic S-MWCNTs were dispersed in a SPES solution at concentrations of 0.5% and 1.0% by weight. These bead membranes are fabricated using a novel electrospinning technique, followed by a post-treatment with the hydrophobic polyfluorinated grafting agent to augment nanofiber membrane surface properties, thereby achieving superhydrophobicity with a water contact angle (WCA) of 145 ± 2° and a higher surface roughness of 512 nm. The enhanced membrane demonstrated a water flux of 87.3 Lm-2 h-1 and achieved nearly 99% salt rejection efficiency at room temperature, using a 3 wt% sodium chloride (NaCl) solution as the feed. The results highlight the potential of superhydrophobic SPES nanofiber beads in revolutionizing MD technology, offering a scalable, efficient, and robust membrane for salt rejection.

Tailored Covalent Organic Framework Platform: From Multistimuli, Targeted Dual Drug Delivery by Architecturally Engineering to Enhance Photothermal Tumor Therapy.

Engineering bulk covalent organic frameworks (COFs) to access specific morphological structures holds paramount significance in boosting their functions in cancer treatment; nevertheless, scant effort has been dedicated to exploring this realm. Herein, silica core-shell templates and multifunctional COF-based reticulated hollow nanospheres (HCOFs) are novelly designed as a versatile nanoplatform to investigate the simultaneous effect of dual-drug chemotherapy and photothermal ablation. Taking advantage of the distinct structural properties of the template, the resulting two-dimensional (2D) HCOF, featuring large internal voids and a peripheral interconnected mesoporous shell, presents intriguing benefits over its bulk counterparts for cancer treatment, including a well-defined morphology, an outstanding drug loading capability (99.6%) attributed to its ultrahigh surface area (2087 m2/g), great crystallinity, improved tumor accumulation, and an adjustable drug release profile. After being loaded with hydrophilic doxorubicin with a remarkable loading capacity, the obtained drug-loaded HCOFs were coated with gold nanoparticles (Au NPs) to confer them with three properties, including pore entrance blockage, active-targeting capability, and improved biocompatibility via secondary modification, besides high near infrared (NIR) absorption for efficient photothermal hyperthermia cancer suppression. The resultant structure was functionalized with mono-6-thio-β-cyclodextrin (β-CD) as a second pocket to load docetaxel as the hydrophobic anticancer agent (combination index = 0.33). The dual-drug-loaded HCOF displayed both pH- and near-infrared-responsive on-demand drug release. In vitro and in vivo evaluations unveiled the prominent synergistic performance of coloaded HCOF in cancer elimination upon NIR light irradiation. This work opens up a new avenue for exciting applications of structurally engineered HCOFs as hydrophobic/hydrophilic drug carriers as well as multimodal treatment agents.

Anti-clogging performance of pervious concrete incorporating hydrophobic agent

The clogging of pervious concrete has always been a concern for many researchers. Hydrophobic agents were added in the pervious concrete in this study to improve its anti-clogging performance based on the lotus effect. Mechanical performance, permeability performance, and anti-clogging performance of pervious concrete were evaluated. The results show that the addition of hydrophobic agents in pervious concrete improved the compressive strength, while the permeability performance was reduced to a certain extent. The anti-clogging performance was significantly improved, indicating that hydrophobic agents may become an effective measure to improve the anti-clogging ability of pervious concrete.

Robust and Superhydrophobic Polydimethylsiloxane/Ni@Ti3C2Tx Nanocomposite Coatings with Assembled Eyelash-Like Microstructure Array: A New Approach for Effective Passive Anti-Icing and Active Photothermal Deicing.

To solve the problem of ice condensation and adhesion, it is urgent to develop new anti-icing and deicing technologies. This study presented the development of a highly efficient photothermal-enhanced superhydrophobic PDMS/Ni@Ti3C2Tx composite film (m-NMPA) fabricated cost-effectively and straightforwardly. This film was fabricated utilizing PDMS as a hydrophobic agent, adhesive, and surface protector, while Ni@Ti3C2Tx as a magnetic photothermal filler innovatively. Through a simple spraying method, the filler is guided by a strong magnetic field to self-assemble into an eyelash-like microstructure array. The unique structure not only imparts superhydrophobic properties to the surface but also constructs an efficient "light-capturing" architecture. Remarkably, the m-NMPA film demonstrates outstanding superhydrophobic passive anti-icing and efficient photothermal active deicing performance without the use of fluorinated chemicals. The micro-/nanostructure of the film forms a gas layer, significantly delaying the freezing time of water. Particularly under extreme cold conditions (-30 °C), the freezing time is extended by a factor of 7.3 compared to the bare substrate. Furthermore, under sunlight exposure, surface droplets do not freeze. The excellent photothermal performance is attributed to the firm anchoring of nickel particles on the MXene surface, facilitating effective "point-to-face" photothermal synergy. The eyelash-like microarray structure enhances light-capturing capability, resulting in a high light absorption rate of 98%. Furthermore, the microstructure aids in maintaining heat at the uppermost layer of the surface, maximizing the utilization of thermal energy for ice melting and frost thawing. Under solar irradiation, the m-NMPA film can rapidly melt approximately a 4 mm thick ice layer within 558 s and expel the melted water promptly, reducing the risk of secondary icing. Additionally, the ice adhesion force on the surface of the m-NMPA film is remarkably low, with an adhesion strength of approximately 4.7 kPa for a 1 × 1 cm2 ice column. After undergoing rigorous durability tests, including xenon lamp weathering test, pressure resistance test, repeated adhesive tape testing, xenon lamp irradiation, water drop impact testing, and repeated brushing with hydrochloric acid and particles, the film's surface structure and superhydrophobic performance have remained exceptional. The photothermal superhydrophobic passive anti-icing and active deicing technology in this work rely on sustainable solar energy for efficient heat generation. It presents broad prospects for practical applications with advantages such as simple processing method, environmental friendliness, outstanding anti-icing effects, and exceptional durability.

A design of gas diffusion media for polymer electrolyte membrane fuel cell: Characterization and water management investigation

Higher power density is a key technological goal for the deployment of polymer electrolyte membrane fuel cells (PEMFCs) in vehicles. Water production is proportional to current density and at high current densities water flooding in catalyst layers can result in significant mass transport limitations. A novel perfluoropolymers material, Teflon™ AF, is introduced as a hydrophobic agent to fabricate microporous layers (MPLs). The MPL ink with varying proportions of Teflon™ AF and Vulcan XC-72 carbon black is prepared and used to coat MPLs into the gas diffusion layers. X-ray computed tomography and mercury intrusion porosimetry are used to characterize the physical properties of the penetrated GDM. The performance of cells with the homemade MPLs are compared with commercial GDM cells under dry and wet operating conditions using varying backpressures. The results at high relative humidity and high backpressure show that the cells with homemade MPLs have less flooding than that with commercial GDM. Oxygen transport resistance measurements using the limiting current method show that the penetration of the MPL into the substrate has an undesirable effect of increasing oxygen transport resistance. The results are of benefit to understanding the water management and gas transport mechanism of MPL for fuel cells operating at both dry and wet conditions.

Geopolymer-based radiative cooling coating: Tailoring surface hydrophobic properties while retaining optical characteristics

The longevity of geopolymer-based radiative cooling coatings is questionable due to their hydrophilic nature. This study used four hydrophobic agents - sodium methyl silicate (SMS), polydimethylsiloxane (PDMS), polytetrafluoroethylene (PTFE), and triethoxyoctylsilane (TEOS) - to modify the surface hydrophobicity of geopolymer while maintaining its optical properties. The optimal agent contents were determined by optical performance and water contact angle: 5 % for SMS, 10 % for 50 cP viscosity PDMS, and a single-layer thickness for PTFE and TEOS (60 °C). The agents' working mechanisms were analyzed using FTIR and XRD characterization: SMS forms a hydrophobic alkylsilanol layer by reacting with the geopolymer's silanol group; PDMS lowers the geopolymer's surface energy with its hydrophobic methyl groups; PTFE's low electric polarizability is due to its fluorine content; and TEOS replaces the geopolymer surface's hydroxyl groups with hydrophobic octyl groups. The long-term durability of these modified coatings was evaluated through outdoor exposure tests, resulting in total solar reflectance losses of 0.74 %, 1.9 %, 3.9 %, and 0.05 % respectively. A slight reduction in the water contact angle confirmed their enduring hydrophobic characteristics. These modification methods open up possibilities for the practical use of hydrophobic geopolymer radiative cooling coatings.

Plant-based delivery systems for controlled release of hydrophilic and hydrophobic active ingredients: Pea protein-alginate bigel beads

Oral delivery systems for nutrients and nutraceuticals are required for personalized nutrition applications. In some applications, these delivery systems need to encapsulate both hydrophilic and hydrophobic bioactive agents. In this study, bigel beads (2 mm) were prepared using pea protein (PP) and sodium alginate (SA) to form the hydrogel phase, and glyceryl monostearate and soybean oil to form the oleogel phase. The hydrogel phase was crosslinked by using Ca2+ ions to form electrostatic bridges between the alginate molecules. The bigel beads had an oil-in-water type structure consisting of an oleogel dispersed phase within a hydrogel continuous phase. These beads were used to encapsulate and control the release of model hydrophobic (curcumin) and hydrophilic (epigallocatechin gallate) nutraceuticals. The textural and microstructural characteristics of the bigel beads were evaluated by dynamic shear rheology, textural profile analysis, cryo-electron microscopy, and fluorescence confocal microscopy. As the concentration of SA increasing from 0.2 to 1.0%, the hardness of bigel beads increased from 306.75 g to 792.40 g. In vitro digestion experiments showed that most of the nutraceuticals were released in the small intestine, rather than the stomach. Nutraceutical release could be controlled by manipulating bead composition, with the extent of nutraceutical release decreasing with increasing alginate concentration. The bigel beads developed in this study could be used as easy-to-swallow carriers for the controlled release of hydrophilic and hydrophobic bioactive ingredients. These kinds of products may be especially useful for people with dysphagia.

Elucidating the effects of surface wettability on boiling heat transfer using hydrophilic and hydrophobic surfaces with laser-etched microchannels

This study explores the nuanced interplay between surface wettability and morphology in nucleate boiling heat transfer. Surfaces with identical microstructures but varying wettability are created on copper substrates using laser texturing and a hydrophobic agent. The spacing between laser-etched microchannels is adjusted to achieve different contact angles and percentages of laser-textured areas. Boiling performance is assessed with variations in channel spacing and surface coverage, revealing significant differences between hydrophilic and hydrophobic surfaces. The critical heat flux (CHF) enhancement mechanisms are identified, emphasizing either enhanced liquid replenishment or separate boiling and liquid-supply regions. A critical laser line spacing of 100 μm is determined, where hydrophobic and hydrophilic variants exhibit similar CHF. Interestingly, hydrophilic surfaces show a weak correlation between the heat transfer coefficient (HTC) and contact angle, while hydrophobic surfaces demonstrate a strong correlation. This separation of surface morphology and wettability confirms that lower wettability promotes early nucleate boiling and high HTC, whereas hydrophilic variants contribute to enhanced CHF with lower HTC. These distinctions are most prominent at high coverage with laser-textured areas and diminish as coverage decreases. The findings provide valuable insights into optimizing surface properties for efficient boiling heat transfer applications.

Hierarchical nanoengineered emulsion with robust adhesion enables superior self-cleaning cotton fabrics

Self-cleaning treatment is of vital importance for the practical application of functional cotton fabrics. However, developing highly efficient, eco-friendly, and durable hydrophobic and oleophobic treatment agents still remains a great challenge. Herein, inspired by the design of the inorganic–organic nanonetwork, we successfully synthesized a novel core–shell structured emulsion of nano-SiO2/fluorine-silicon polyacrylate through semi-continuous emulsion polymerization. The introduction of long-chain alkyl methacrylate octadecyl ester within the shell phase results in a more organized arrangement of fluorine atoms on the surface of cotton fabrics, leading to a rapid reduction in the surface free energy of latex film. The sample is optimized with 20 wt% dodecafluoroheptyl methacrylate and 1 wt% SiO2. The nanoengineered emulsion exhibits strong adhesion and effectively transforms the hydrophilic cotton fabrics into hydrophobic (143.2°) and oleophobic (121.6°) materials. Besides, the self-cleaning characteristic can withstand 25 laundering cycles and 800 abrasion cycles with enhanced robustness. This work opens up a pathway to develop effective, green but long-lasting amphiphobic agents for functional fabrics and sustainable textiles.