Inherent Porosity Research Articles

Research Progress in Enhancing Proton Conductivity of Sulfonated Aromatic Polymers with ZIFs for Fuel Cell Applications

The escalating global temperatures and their adverse effects underscore the growing imperative for the widespread adoption of clean fuels, notably hydrogen. Proton Exchange Membrane Fuel Cells (PEMFC) emerge as a pivotal green energy technology, facilitating electricity and water generation. The optimization of PEMFC efficiency hinges on the judicious selection and fabrication of polymer membranes. Within innovative materials, Zeolitic Imidazolate Frameworks (ZIFs) represent a novel subclass within the expansive family of Metal-Organic Frameworks (MOFs). ZIFs exhibit promising potential in PEMFCs, owing to their distinctive properties such as a substantial contact surface, inherent porosity, and a sizable pore volume. This comprehensive review delves into composite membranes featuring ZIFs, shedding light on their chemical and thermal attributes. Additionally, the exploration extends to elucidating the diverse applications of ZIF compounds, accompanied by an in-depth discussion of selected chemical and thermal properties inherent to ZIF compounds. Incorporating ZIFs into various polymers yielded intriguing outcomes, demonstrating a notable enhancement in proton conductivity. The compilation of this review aims to provide researchers with foundational insights into the realm of ZIFs, serving as a valuable resource for future investigations and advancements in the field.

Recent Advances in Nanozyme Sensors Based on Metal–Organic Frameworks and Covalent–Organic Frameworks

Nanozymes are nanomaterials that exhibit enzyme-like catalytic activity, which have drawn increasing attention on account of their unique superiorities including very high robustness, low cost, and ease of modification. Metal–organic frameworks (MOFs) and covalent–organic frameworks (COFs) have emerged as promising candidates for nanozymes due to their abundant catalytic activity centers, inherent porosity, and tunable chemical functionalities. In this review, we first compare the enzyme-mimicking activity centers and catalytic mechanisms between MOF and COF nanozymes, and then summarize the recent research on designing and modifying MOF and COF nanozymes with inherent catalytic activity. Moreover, typical examples of sensing applications based on these nanozymes are presented, as well as the translation of enzyme catalytic activity into a visible signal response. At last, a discussion of current challenges is presented, followed by some future prospects to provide guidance for designing nanozyme sensors based on MOFs and COFs for practical applications.

Impact of Trichoderma spiralis Treatment on the Photothermal Water Evaporation Capacity of Poplar

In recent years, research on interfacial photothermal water evaporation has been thriving. Due to its inherent porosity, exceptional hydrophilicity, and renewable characteristics, wood has garnered significant attention as a material for interfacial photothermal evaporation absorbers. In order to enhance the cellular channels of poplar and improve its water migration capacity, Trichoderma spiralis was selected to inoculate and culture poplar specimens from different sections for 3, 5, and 7 weeks. Simultaneously, a solar radiation intensity of 1 kW·m⁻2 was simulated to perform photothermal evaporation tests on the specimens. This validated the water migration capabilities of different sections of poplar treated with Trichoderma spiralis under light and heat exposure. The characteristic changes were analyzed using electron microscope scanning, infrared spectrum analysis, X-ray photoelectron spectroscopy analysis, surface infiltration performance, and automatic specific surface porosity. The results suggested that the moderate degradation of cellulose and hemicellulose in poplar by Trichoderma spiralis could dredge the cell channels and improve the permeability of poplar, particularly with regard to lateral permeability. The maximum photothermal evaporation rate of the poplar specimen reached 1.18 kg m⁻2 h⁻1, while the evaporation efficiency increased to 72.2%.

Recovered Foam Impact Absorption Systems

The use of foam materials in environments where they come into contact with individuals often results in deterioration, necessitating periodic replacements to maintain safety and hygiene standards. Foam, a lightweight, porous plastic formed by aggregated bubbles, possesses excellent impact-absorbing properties; however, its inherent porosity and susceptibility to wear present challenges. This project aims to develop a technological application for repurposing spent polyurethane (PU) foam from leisure facilities into effective impact absorption systems. By focusing on the reuse of deteriorated foam materials, this initiative seeks to minimize environmental impact while leveraging their beneficial technical characteristics. Addressing issues related to foam degradation, this project endeavors to create sustainable solutions by reintegrating spent foam into new systems. This innovative approach promotes sustainability while enhancing safety through the provision of high-quality, impact-resistant elements. Ultimately, this work aims to contribute to environmental conservation and the advancement of effective impact protection measures in leisure facilities.

Assembly of Eosin Y in-situ intercalated Zr-MOF composite for decontaminating Cr(VI) and reactive dyes via physical capture and photochemical purification

Post-modification based on highly water stable Zr-MOF introduces a novel dimension of functional regulation, offering a fresh perspective for the advancement of pragmatic photocatalysts in the water treatment field. In this study, an entirely novel Zr-MOF (NU-1400-py), featuring a topological network identical to that of NU-1400, has been assembled. The main difference is the replacement of TPTC's central benzene ring with a pyrimidine ring. Utilizing the inherent porosity and semiconducting properties, this Zr-MOF possesses the capability to physically trap Cr2O72- ions (136.43 mg/g), achieving photochemical purification of Cr(VI) and K-, X-, M-type reactive dyes from water. Moreover, another novel heterojunction material EY@Zr-MOF, has been fabricated via in-situ intercalation of luminescent Eosin Y (EY) species within Zr-MOF. Due to the sensitization of embedded EY molecules, EY@Zr-MOF exhibits significantly optimized interface resistance, transient photocurrent intensity and carrier migration efficiency compared to pristine Zr-MOF. Notably, the photochemical purification efficiencies of EY@Zr-MOF towards Cr2O72- (99.66 %, 30 min), RB13 (90.18 %, 120 min), RR2 (92.40 %, 300 min) and RR11 (84.80 %, 90 min) have been dramatically elevated, offering the considerably accelerated reaction kinetics of 1.24, 4.82, 2.48 and 6.23 times, respectively, compared to pristine Zr-MOF, the photochemical purification efficiencies of Zr-MOF towards Cr2O72- (97.88 %, 30 min), RB13 (85.55 %, 450 min), RR2 (71.38 %, 450 min) and RR11 (53.16 %, 240 min). Additionally, its photocatalytic REDOX mechanisms in eliminating target contaminants were proposed tentatively. This contribution offers a viable pathway for designing multi-functional materials aimed at solving some intractable environmental issues caused by Cr(VI) and reactive dyes.

Rational Design of Highly Porous Donor-Acceptor Based Conjugated Microporous Polymer for Photocatalytic Benzylamine Coupling Reaction.

Conjugated microporous polymers (CMPs) are an important class of organic materials with several useful features like, inherent nanoscale porosity, large specific surface area and semiconducting properties, which are very demanding for various sustainable applications. Carbazole building blocks are extensively used in designing photocatalysts due to easy electron donation and hole transportation. In the current study, a new CMP material CBZ-CMP containing carbazole unit used for photocatalytic C═N coupling reaction under blue light irradiation is designed. The CBZ-CMP framework is made through the polycondensation of 4,4'-di(9H-carbazol-9-yl)-1,1'-biphenyl using FeCl3 as a catalyst. The CBZ-CMP shows very high BET surface area of 1536 m2 g-1 together with unimodal porosity (ca. 1.7nm supermicropore), nanowire-like particle morphology (16-18nm diameter), and low band gap property. The bi-phenyl moiety functions as the electron accepting center and the carbazole unit acts as the donor center, which accounts for the low band gap energy of CBZ-CMP. This nanoporous semiconducting CBZ-CMP material for photocatalytic benzylamine coupling reaction is explored, where it shows good conversion together with high selectivity under mild reaction conditions. This study offers simple method of preparation of a D-A-D-based porous photocatalyst for sustainable synthesis of value-added organics.

Inherent porosity of Zeolitic Imidazolate Framework-62 melt leading to formation of the porous melt-quenched glass

Porous glasses produced through melt-quenching of some selective metal organic frameworks like Zeolitic Imidazolate Framework-62 (ZIF-62) and ZIF-4 belong to the advanced functional materials because of their inherent porosity, ease of processing, high gas adsorption capacity and gas separation selectivity. We have delineated thermal induced modifications in the porosity features (pore size, size-distribution and pore density) of crystalline ZIF-62 from room temperature (RT) to its melt-state (> melting point, Tm) followed by its quenching, back to RT, carrying out the depth sensitive positron annihilation lifetime spectroscopy (PALS) measurements in-situ at varying temperatures (RT−Tm). On heating under vacuum, the pores' size as well as size-distribution of crystalline ZIF-62 increases up to ∼473 K as a consequence of removal of entrapped solvent molecules and nonuniform thermal expansion. At higher temperatures (∼473 −573 K), a reduction in pores’ size and size-distribution is observed due to the loss of long range ordering and volume collapse. On melting, ZIF-62 turns into a porous liquid having ∼1.4 times larger pores compared to its crystalline form. The quenching of this porous melt is fully irreversible, and results in the formation of a porous glass having the pores larger than its crystalline counterpart. The in-situ PALS investigation provides the first experimental evidence of inherent porosity in ZIF-62 melt existing at high temperature that has been predicted before through molecular dynamics simulation of the ZIFs-based melts.

Cracking resistance behavior of HVAF-sprayed monolayer and hierarchical Fe-based amorphous coatings under bending stress

The bending strength and fracture toughness are two key indicators that determine the service performance of thermally sprayed Fe-based amorphous coatings (AMCs) in harsh environments. Unfortunately, due to the inherent heterogeneous porosity and limited thickness (typically <1 mm) of the coatings, obtaining these properties is constrained by traditional fracture analysis methods. To address this, a three-point bending combined with the digital image correlation (DIC) method, without prefabricating notch or removing substrate, was proposed in the current work, and the effect of hierarchical structures on the fracture performance of the coatings was successfully revealed. Excitingly, the results show that compared to monolayer coating, hierarchical structures comprising two layers with different porosities can realize the synergistic improvement in the fracture strength and fracture strain of the coatings by alleviating local stress concentration and inducing crack deflection. Further, a finite element method (FEM) was employed to gain insight into the intrinsic relationship between the coating microstructures and the crack evolution behavior. This work not only proposes a simple method for evaluating the fracture performance of Fe-based AMCs sprayed with high velocity air fuel (HVAF), but also presents an innovative idea for optimizing the coating's properties.

Design and assembly of conductive covalent organic frameworks for proton exchange membrane application

To develop proton exchange membranes (PEMs) with robust structure stability and remarkable proton conductivity and explore their application in PEMs fuel cells have significant implications for realizing reduced carbon emission and environmental pollution. Covalent organic frameworks (COFs), as crystalline porous polymer material composed of organic monomers and connected by covalent bond, possess specific framework, inherent porosity, adjustable functional group and eminent thermal/chemical structure stability. Therefore, COFs display prominent superiorities in constructing rigid ordered proton transfer channels and improving fuel cell performance long‐term durability. In this review, the proton conduction properties of extrinsic proton‐conductive COFs (incorporating carriers into the pore), intrinsic proton‐conductive COFs (introducing conductive groups on the backbone) and combined extrinsic/intrinsic proton‐conductive COFs in the form of pressed pellets are discussed in detail. Meanwhile, proton‐conductive COFs related PEMs, including COFs‐related polymer‐based composite membranes, COFs‐based composite membranes and self‐supporting COFs membranes are also systematically summarized. In addition, the existing challenges are analyzed and future outlooks are addressed.

Heavy-Atom-Free Covalent Organic Frameworks for Organic Room-Temperature Phosphorescence via Förster and Dexter Energy Transfer Mechanism.

Covalent organic frameworks (COFs), with their accessible nanoscale porosity, selectable building blocks, and precisely engineered topology, offer unique benefits in the design of room-temperature phosphorescent (RTP) materials. However, their potential has been limited by phosphorescence quenching caused by interlayer π-π stacking interactions. This paper presents a novel strategy to enhance RTP in heavy-atom-free COFs by employing a donor-acceptor (D-A) system that leverages the Förster resonance energy transfer (FRET) and Dexter energy transfer (DET) mechanisms. Among the materials investigated, the best-performing COF exhibits a phosphorescence lifetime of 4.35ms at room temperature. Spectral analysis, structural analysis, and theoretical calculations indicate the presence of intralayer FRET processes as well as interlayer DET processes within the D-A COF system. Potential anti-counterfeiting applications are explored by exploiting the unique phosphorescent properties of these materials. Additionally, the inherent permanent porosity of COFs presents new opportunities for future development and application. This strategy offers many promising prospects for advancing the RTP technology in COF materials and broadens their potential applications in various fields.

3D‐Printed Highly Porous Functional Materials for the Efficient Removal of Adenovirus

AbstractHierarchical porous acrylate‐based materials are highly interesting as 3D filter materials, such as for virus removal from suspensions. Here, the synthesis of highly porous monolithic 3D materials by polymerization‐induced phase separation in liquid crystal display (LCD) based 3D printing is presented for the efficient removal of human adenovirus type 5. The hierarchical porosity can be tuned via the variation of the photocurable resin composition (i.e., inherent porosity) and the computer‐aided design (i.e., “printed” porosity; microchannels). 3D polymer structures with highly intricate geometries and structural features ranging from ≈20 nm up to cm can be achieved, which can be used for effective virus removal in a laboratory‐scale flow‐through approach. Combined focused ion beam/scanning electron microscopy tomography and mercury porosimetry provide detailed information on the inherent pore size, pore size distribution, and pore interconnectivity, which is key for the performance of such functional 3D materials. Polymers with a theoretical void volume of 75% show virus capture with a removal efficiency of ≈70% of the adenovirus. Polymers with the same theoretical void volume and macroscopic design but a more hydrophobic nature captured only ≈33%. An optimized adenovirus retention of 98% is achieved by adjusting the microchannels of the tunable inserts.

A seamless auxetic substrate with a negative Poisson’s ratio of −1

Auxetic metamaterials are a unique class of materials or structures with a negative Poisson’s ratio and a wide array of functionalities. However, their inherent porosity presents challenges in practical applications. Filling the inherent perforations while preserving their unique auxeticity is difficult because it demands the seamless integration of components that have highly distinct mechanical characteristics. Here we introduce a seamless auxetic substrate film capable of achieving a negative Poisson’s ratio of −1, the theoretical limit of isotropic materials. This breakthrough is realized by incorporating a highly rigid auxetic structure reinforced by glass-fabric, with surface-flattening soft elastomers. We effectively optimize the mechanical properties of these components by systematic experimental and theoretical investigations into the effects of relative differences in the moduli of the constituents. Using the developed auxetic film we demonstrate an image distortion-free display having 25 PPI resolution of micro-LEDs that is capable of 25% stretching without performance degradation.

Chromoionophoric molecular probe infused bimodal porous polymer rostrum as solid-state ocular sensor for the selective and expeditious optical sensing of ultra-trace toxic mercury ions

This study presents a distinctive solid-state naked-eye colorimetric sensing approach by encapsulating a chromoionophoric probe onto a hybrid macro-/meso-pore polymer scaffold for fast and selective sensing of ultra-trace Hg(II). The customized structural/surface properties of the poly(VPy-co-TM) monolith are attained by specific proportions of 2-vinylpyridine (VPy), trimethylolpropane trimethacrylate (TM), and pore-tuning solvents. The interconnected porous network of poly(VPy-co-TM), inherent superior surface area and porosity, is captivating for the homogeneous/voluminous incorporation of probe molecules, i.e., 7-((4-methoxyphenyl)diazenyl)quinoline-8-ol (MPDQ), for the target-specific colorimetric detection. The structural morphology, surface topography, and phase characteristics of the bare poly(VPy-co-TM) monolith and MPDQ@poly(VPy-co-TM) sensor are examined using HR-TEM-SAED (High-Resolution Transmission Electron Microscopy - Selected Area Electron Diffraction), FE-SEM-EDAX (Field Emission Scanning Electron Microscopy - Energy Dispersive X-ray Spectroscopy), XPS (X-ray Photoelectron Spectroscopy), p-XRD (Powder X-Ray Diffraction), FT-IR (Fourier Transform Infrared Spectroscopy), UV-Vis-DRS (Ultraviolet-Visible Diffuse Reflectance Spectroscopy), and BET/BJH (Brunauer-Emmett-Teller / Barrett-Joyner-Halenda) analysis. The distinctive properties of the sensor reveal a constrained geometrical orientation of the MPDQ probe onto the long-range continuous monolithic network of meso-/-macropore template, enabling selective interaction with Hg(II) with peculiar color transfiguration from pale yellow to deep brown. The sensor demonstrates a linear spectral-color alliance in the 0–200 ppb concentration range for Hg(II), with quantification and detection limits of 0.63 and 0.19 ppb. The sensor efficacy is verified using certified contaminated water and tobacco samples, with excellent reusability, reliability, and reproducibility of ≥ 99.23 % (RSD ≤1.89 %) and ≥ 99.19 % (RSD ≤1.94 %) of Hg(II), respectively.

Study on the characteristics of novel fiber extracted from Foxtail palm fruits – A steps towards the sustainable development

This study explores the properties of fibers extracted from the fruits of the Foxtail palm (FPF) and assesses their potential for advancing sustainable development. Antibacterial assays demonstrated that these fibers significantly inhibit the growth of gram-negative bacteria, including Pseudomonas aeruginosa and Salmonella enterica, with inhibition zones of 24 mm and 30 mm, respectively. X-ray diffraction analysis revealed a predominantly crystalline structure, which is crucial for use as reinforcing materials, showing distinct peaks at 20° and 30° diffraction angles that signify the presence of cellulose I. Fourier-transform infrared spectroscopy confirmed the fibers’ complex composition of cellulose, hemicellulose, and lignin, indicated by the presence of hydroxyl, carbonyl, and aliphatic functional groups. Scanning electron microscopy analysis showed a rough and irregular surface texture adorned with numerous microfibrils and cavities, which are beneficial for mechanical interlocking with polymer matrices. The densely arranged cellulose microfibrils, approximately 210 µm in diameter, lend the fibers high tensile strength and stiffness. Although some surface imperfections were observed, the inherent porosity of the fibers facilitates resin absorption, enhancing their reinforcement capabilities in composite materials.

Disposability, social security, and the facts of work in Nicaragua’s sugarcane zone

ABSTRACT This article explores the instability of facts surrounding former sugarcane workers in Nicaragua with Chronic Kidney Disease of Non-Traditional Causes (CKDnt). CKDnt is a progressive disease that has been linked, albeit inconclusively, to working conditions in sugarcane plantations and other extreme environments. It emerged in the early twenty-first century, at a time when the social and political value of agricultural labor in Nicaragua and across the Americas was shifting due to the rise of new regimes of corporate responsibility and neoliberalized systems of state care. Partly as a result of a lack of conclusive knowledge about what causes the disease, former workers receive uneven medical and social benefits from both sugarcane corporations and the Nicaraguan social security system, the Instituto Nacional de Seguridad Social (INSS). This article traces the parallel emergence of Nicaragua’s agro-economy and the INSS during the twentieth century, and it draws on ethnographic research with ex-workers to understand how the making of facts about work and the making of facts about health shape each other. The article argues that the disposability of labor is not an inherent feature of monocrop capitalism; rather, disposability emerges as corporations and state authorities work strategically to manage the inherent porosity of the boundaries between plantations and their socio-political surroundings.

Single atom intercalation in 2D triazine-based (g-C6N6) and boroxine-based (B6O6) porous covalent organic framework bilayers and heterostructures

Covalent organic frameworks (COFs) are new class of organic porous materials with tunable pore size and low weight density, demonstrating remarkable potential applications in gas storage, gas separation, and catalysis. The inherent periodic porosity of COF monolayers (MLs) establishes anchoring sites for single atoms. Using first-principles calculations, we study the structural and electronic properties of atom-embedded C6N6 and B6O6 MLs. Subsequently, the intercalation of atoms between C6N6 and B6O6 bilayers (BLs) and their heterostructure (HTS) are investigated. Our findings show the significant effects of embedded atoms on the structural parameters of the host material. Notably, the Li atom anchors within the pore region of C6N6 ML without forming bonds, while it establishes two σ bonds with O atoms in B6O6 ML. The Cs atom forms six bonds in both MLs and resides between layers in BLs. In the HTS, the Cs atom forms six bonds with N atoms of the C6N6 layer, positioning in the middle of the layers. Calculations reveal that Li and Cs atoms induce a red shift in energy, leading to a semiconductor–metal transition. Conversely, the insertion of an F atom induces a blue shift in energy, creating a midgap state at the Fermi energy.

Porosity and bedding controls on bio-induced carbonate precipitation and mechanical properties of shale and dolomitic rocks: EICP vs MICP

Biocementation is an emerging field within geotechnical engineering that focuses on harnessing microbiological activity to enhance the mechanical properties and behavior of rocks. It often relies on microbial-induced carbonate precipitation (MICP) or enzyme-induced carbonate precipitation (EICP) which utilizes biomineralization by promoting the generation of calcium carbonate (CaCO3) within the pores of geomaterials (rock and soil). However, there is still a lack of knowledge about the effect of porosity and bedding on biocementation in rocks from a mechanistic view. This experimental study investigated the impact of porosity and bedding orientations on the mechanical response of rocks due to biocementations, using two distinct biocementation strategies (MICP and EICP) and characteristically low porosity but interbedded rocks (shale) and more porous but non-bedded (dolostone) rocks. We first conducted biocementation treatments (MICP and EICP) of rock samples over a distinct period and temperature. Subsequently, the rock strength (uniaxial compressive strength, UCS) was measured. Finally, we analyzed the pre- and post-treatment changes in the rock samples to better understand the effect of MICP and EICP biocementations on the mechanical response of the rock samples. The results indicate that biocementations in dolostones can improve the rock mechanical integrity (EICP: +58% UCS; MICP: +25% UCS). In shales, biocementations can either slightly improve (EICP: +1% UCS) or weaken the rock mechanical integrity (MICP: −39% UCS). Further, results suggest that the major controlling mechanisms of biogeomechanical alterations due to MICP and EICP in rocks can be attributed to the inherent porosity, biocementation type, and bedding orientations, and in few cases the mechanisms can be swelling, osmotic suction, or pore pressurization. The findings in this study provide novel insights into the mechanical responses of rocks due to MICP and EICP biocementations.

Microwave-synthesized heteroaromatic porous organic polymers for CO2 capture and hydrogen storage

In this paper, three porous organic polymers (POPs) were synthesized by microwave-assisted Friedel-Crafts polymerization reaction of 1,3,5-tris(2-thienyl)benzene (TTB) with furan (HAF), thiophene (HAT), and pyrrole (HAP) in the presence of dimethoxymethane using anhydrous iron (III) chloride as a catalyst. The polymers displayed inherent porosity, with BET surface areas ranging from 528 to 634 m2/g. These polymers exhibited high CO2 adsorption capacity, with values of 2.61, 2.17, and 2.37 mmol/g at 273 K and 1 atm, as well as strong affinity, with Qst values of 43–48 kJ/mol. The polymers showed hydrogen storage of 3.3–5.3 mmol/g (0.66–1.06 wt%) at 77 K, and 1 atm. The polymers showed Initial slope selectivity for CO2/N2: 34–61 at 273 K and 1 atm, and 23–57 at 298 K and 1 atm. Whereas, the polymers showed initial slope selectivity for CO2/CH4: 5–9 at 273 K and 4–7 at 298 K and 1 atm. Besides, the HAP at 273 K and HAF at 298 K showed highest IAST selectivity values of 231.18 and 257.49, respectively. Grand Canonical Monte Carlo (GCMC) simulations revealed that the polymers exhibit matching electronic properties with CO2 molecules and achieve excellent selectivity in accordance with the hard-soft acid-base (HSAB) theory. These findings demonstrate the potential of these polymers for CO2 capture and clean energy applications.

Environmentally friendly calcium carbonate-polydopamine microcapsules with superior mechanical, barrier, and adhesive properties

There is a rising need to deliver perfume molecules to fabric surfaces during washing cycles to enhance consumers' perception. With upcoming regulations phasing out intentionally produced microplastics by 2027, the focus is on sustainable alternatives to conventional non-biodegradable synthetic microcapsules (e.g. melamine-formaldehyde). Calcium carbonate (CaCO3) has shown promise to form the microcapsule shells due to its environmental benignity, inexpensiveness, and potential for liquid formulations, particularly detergents. Notwithstanding, its inherent porosity undermines the performance of the ensuing microcapsules. Bio-inspired by the adhesive properties of mussel proteins, dopamine is proposed for forming a protective organic coating on CaCO3-based microcapsules. This research aims towards developing primary microcapsules with CaCO3 shells encapsulating hexylsalicylate (HS) as a perfume oil, applying a polydopamine (PDA) coating via oxidative auto-polymerisation of dopamine-hydrochloride (pH 8.5), and conducting a comprehensive analysis of morphological, mechanical, barrier, and adhesive properties through advanced techniques, namely fluorescent-sensing/scanning electron microscopy (SEM), micromanipulation, UV–Vis spectrometry, and a microfluidic chamber fitted with polyethylene-terephthalate (PET) fabrics. The obtained microcapsules (D[3, 2]=31.2 ± 0.4 μm) exhibited a spherical core-shell structure with a smooth PDA-coated surface. Mechanical assessments reveal remarkable rupture stress (2.2 ± 0.3 MPa) comparable to that of commercial microcapsules. After one month in water, ∼40% of HS was released from PDA-coated microcapsules, while the primary ones released the entire amount within 4 h. When mimicking washing conditions (pH 9), the PDA-coated microcapsules demonstrated improved retention (∼60%) on the PET substrate at hydrodynamic shear stress of ∼1 Pa, whereas that of the primary microcapsules was below 10%. Overall, this study suggests the successful fabrication of eco-friendly microcapsules featuring a hybrid inorganic-organic shell, with enhanced mechanical strength, reduced leakage, and improved adhesion, showcasing their potential in applications within the fast-moving consumer goods industry.

Advanced Nanostructured All‐Waterborne Thiol‐Ene/Reduced Graphene Oxide Humidity Sensors with Outstanding Selectivity

AbstractThe current‐state of polymer‐based humidity sensors faces numerous limitations, including energy‐costly synthesis, low sensitivity, and slow response times. This study presents innovative approach to overcome these challenges, based on a robust all‐water‐borne in situ miniemulsion polymerization. The use of water throughout the entire process mitigates the negative environmental impact. Thiol‐ene polymers reinforced with reduced graphene oxide (rGO) with concentrations ranging from 0.2–1.0 wt% are selected to fabricate these chemoresistive sensors. The selected thiol‐enes present high hydrophobicity and a semicrystalline nature, suggesting resistance to early delamination even under prolonged exposure to humidity. Incorporating rGO not only imparts electrical conductivity but also enhances mechanical and water resistance of the composite films. The 0.6% rGO composite exhibits optimal resistance for humidity sensing, demonstrating rapid and consistent responses across three exposure cycles to water vapor concentrations ranging 800–5000 ppm. Moreover, the sensor exhibits remarkable selectivity toward water vapors over these of toluene, propanol, and 4‐methyl‐2‐pentanol, attributed to the high surface hydrophilicity and inherent porosity of the waterborne film, and network structuring of rGO platelets within the matrix. In summary, this study pioneers a novel approach to polymer‐based humidity sensing, addressing key limitations while offering enhanced sensitivity, rapid response times, and superior selectivity.