Flexible carriers that combine high drug loading and favorable drug compatibilities with a wider spectrum of more defined release properties are needed to broaden the scope of transdermal drug delivery systems (TDDS). Here, we transform rigid porous glass into flexible textile architectures by drawing SiO2-B2O3-Na2O fibers (50 and 150 & micro;m in diameter), inducing phase separation through controlled thermal treatment, and generating porosity via selective leaching. Differential scanning calorimetry revealed glass transition temperatures (T g) to be 40 degrees C-50 degrees C higher for fibers than for bulk glass, necessitating higher treatment temperatures in order to obtain comparable mesoporosity. After leaching, all materials exhibited similar to 20 nm pores. Woven textiles were fabricated using non-porous S2 warp threads and porous glass weft fibers, yielding 2 & times; 2 cm2 fabrics with preserved flexibility. Using anastrozole as a model drug, in vitro release experiments in a stirred container showed geometry-dependent drug release. Membranes delivered the payload within similar to 10 min. Alkaline-leached textiles displayed a similar burst profile but markedly higher loading capacities. Acid-leached textiles containing residual colloidal silica showed a gradual release over 24 h, reflecting increased tortuosity. Collectively, these results demonstrate that porous glass fiber textiles unite macroscopic flexibility with tunable pore architecture and drug transport, offering an inorganic platform that spans rapid to sustained release regimes and complements polymer-based TDDS.

This study focused on the development and assessment of composite microfiltration (MF) membranes for the selective adsorption-based removal of endocrine-disrupting compounds (EDCs), specifically 17 beta-estradiol (E2) and testosterone (TST), as emerging hazardous micropollutants in drinking water and natural water sources. The preparation of the composite membranes combined polyethersulfone (PES) with molecularly imprinted polymer (MIP) particles, synthesized through precipitation polymerization. Molecular imprinting was performed by utilizing E2 and TST as templates to create specific recognition sites, while non-imprinted polymers (NIPs) served as references. With the deposition of a MIP/NIP particle layer between two PES layers, sandwich-type composite membranes were prepared and further characterized using scanning electron microscopy (SEM), water permeance, and EDC adsorption tests, which were central to evaluating the effectiveness of molecular imprinting in the MIP-based composite membranes. By comparing EDC adsorption loadings between reference PES and composite membranes through dynamic adsorption experiments, the study assessed the adsorption capacity, selectivity and reusability of the membranes after regeneration cycles. The main objective was to determine whether double-target MIP particles for E2 and TST could be synthesized and incorporated into composite membranes with dual selectivity. Following successful membrane integration, imprinting, and synthesis, the double-target MIP membranes efficiently adsorbed TST (0.48 & micro;g mg-1) and E2 (0.51 & micro;g mg-1). Membrane reusability was tested, revealing that composite membranes do not lose adsorption capacity over at least three cycles. Double-target MIP membranes show promise in effective, low-pressure, low-energy removal of EDCs in water treatment applications.

A continuous, electron beam-assisted method was developed for the simultaneous immobilization of proteins within polyethersulfone (PES) hollow fiber membranes during the phase inversion process. The introduction of biomolecules into the bore liquid during spinning, in combination with in-line electron beam irradiation, resulted in surface grafting without the necessity of using chemical coupling reagents. The process was found to preserve the structural integrity and ultrafiltration performance of the membranes, while enabling the controlled immobilization of proteins. The analysis of fluorescently labeled immobilized biomolecules via confocal laser scanning microscopy (CLSM) revealed a preference for immobilization of both bovine serum albumin (BSA) and smaller lysozyme molecules on the lumen surface. This phenomenon has been attributed to electrostatic interactions between the proteins and the membrane, as well as to size exclusion. The electron beam dose had a significant effect on the immobilization efficiency for lysozyme, with the highest protein loading observed at 300 kGy (178 +/- 6 mg/m2). This study proposes a scalable, rapid, and environmentally sustainable method to produce functionalized hollow fiber membranes that have the potential for application in biocatalytic, antifouling, or biomedical applications.

The thermal conductivity and mechanical strength of porous materials are critically influenced by their internal architecture. Beyond the total porosity, the hierarchical arrangement of pore sizes governs whether heat transfer is dominated by continuum conduction or Knudsen effects, and whether the solid network can efficiently carry mechanical loads. Despite this recognized importance, the specific contribution of mesopores within a macroporous scaffold has remained unclear. In this study, we systematically investigate the role of a secondary mesopore system in hierarchically structured silica xerogels. By combining controlled sol-gel synthesis with polymer-induced phase separation and subsequent calcination, we generate bimodal monoliths with tailored mesopore volumes and structurally comparable macroporous frameworks. Selective reduction of mesopores at 950 °C yields macropore-dominated reference samples, enabling direct assessment of mesoporosity effects. Morphological analysis confirms that mesopore reduction leads to densification within the silica struts, accompanied by moderate macropore shrinkage but preservation of the overall network geometry. Thermal conductivity measurements reveal a pronounced decrease of up to 53

Herein, a sustainable direct foaming method for the synthesis of open-cell sodium-borosilicate glass foams is presented. For the foaming process, sodium borosilicate (SBS) waste-glass-powder is ball-milled with manganese carbonate and mixed with an aqueous solution containing citric acid (CA), sodium-waterglass (WG), sodium lauryl ether sulfate (SLES), and guar gum. During mixing, CO2 gas is released, creating a liquid foam that quickly hardens due to condensation of the dissolved silica. After drying and sintering, the foams are submitted to a thermally induced phase separation and subsequent leaching. At 700 degrees C, a low-density foam of 0.22 g & centerdot;cm(-3) with a compressive strength of 0.5 MPa is obtained. After leaching, an additional macropore system in the struts with pore diameters ranging from 50 to 200 nm is introduced. The density is almost halved to 0.13 g & centerdot;cm(-3), and the strut pore volume is increased to 0.7 cm(3)& centerdot;g during leaching. The low pressure drop of around 40 Pa & centerdot;cm(-1) at a gas flow velocity of 0.5 m & centerdot;s(-1) of the open-cell network makes the hierarchically porous silica monoliths suitable as catalyst supports. During the synthesis process, mainly sustainable and nontoxic starting materials are being used, making the whole process environmentally friendly.

A simple method to synthesize catalytically active, noble metal free cobalt ferrites with mesopores and high activity for CO-oxidation at low temperatures will be presented in the following work. Fe4[Fe(CN)6]3 (Prussian blue, PB) and Co3[Fe(CN)6]2 (Co- Prussian blue-analogue, PBA) are first synthesized by a co-precipitation reaction and subsequently heat treated to form the catalytically active oxide CoFe2O4. Solvent modification with DMF and a salt-filler-calcination method with MgSO4 will be employed for the first time to modify and protect the pore system of CoFe2O4. The as obtained mesoporous material has a specific surface area of 76 m2 g− 1, pore sizes ranging from 10 to 70 nm and a specific mesopore volume of 0.4 cm3 g− 1. In a fixed bed-setup with dry air, the material shows 90

Open-cell foam glasses are ideal model systems for investigating the mechanical behavior of macroporous materials. However, a detailed mechanistic understanding linking specific pore-scale features to mechanical failure remains a key challenge. In this study, we investigated the relationships between pore structure and mechanical properties, specifically Young's modulus and compressive strength, in three open-cell monolithic foam glass samples, which serve as model systems for macroporous silica monoliths. With the results of micro-computed tomography (micro-CT) combined with ex-situ and in-situ uniaxial compression experiments and Digital Volume Correlation (DVC) analysis we demonstrate an inverse relationship between mechanical strength and factors including wall thickness and porosity, with compressive strength following a power-law correlation with the proportion of large pores. Multi-peak stress-strain behavior indicates micro-cracking within the porous lattice, while micro-CT imaging reveals damage localization at the specimen boundaries and strain-induced changes in porosity, mean pore diameter, and sphericity. DVC analysis further validated these findings. This work provides mechanistic insights essential for the rational design and optimization of macroporous materials.

Changing the process conditions for the preparation of hollow fiber membranes can result in significant alterations of the structure and performance of the resulting membrane. Consequently, the preparation of membranes with the desired membrane structure using new, environmentally friendly solvents require a large amount of experimental data. The design of experiments (DoE) approach represents a valuable tool for the development of new membranes with high performance through a reduced number of experiments. Additionally, it facilitates the understanding of the correlation between preparation parameters and the resulting membrane structure, performance, and mechanical properties. Given the necessity of reducing the environmental impact of membrane preparation through the replacement of conventional solvents, the design of new membranes using more environmentally friendly solvents is a crucial objective. In this study, the DoE approach was employed to develop macrovoid-free hollow fiber membranes using the less harmful and more environmentally friendly solvent N,N-dimethyl lactamide. Empirical models were established allowing the prediction of membrane structure and mechanical strength. Consequently, the optimal settings of the DoE allowed the preparation of an ultrafiltration membrane that exhibited the desired mechanical strength (6 MPa), retention (cut-off at 100 kDa), permeance (50 LMHB), and homogeneous structure (at least 99 % sponge-like structure).

Research and development in the field of glass-based laser additive manufacturing continues to receive significant interest within scientific and industrial contexts. In particular, powder bed fusion by laser radiation (PBF-LB) enables the additive manufacturing of porous and vitrified, complex three-dimensional components. The present study investigates the glass morphology that can be achieved using PBF-LB for components made from alkali borosilicate glass. The investigations focus on the comprehensive analysis of the entire process window, including the characterisation of porous and molten glass morphology. In particular, the influence of different laser-beam diameters, which are achieved through defocusing, and the variation in volume energy density are examined in detail and compared with conventional shaping. It was determined that the process of mechanically stable shaping is constrained to temperatures above the softening temperature and relative component densities within the range of ρrel = 37.8…94.2%. Furthermore, it has been demonstrated that the process-related line-like energy input results in the formation of characteristic vitrification strands. This research contributes to the overall understanding of the producible glass morphology and the process limitations of the PBF-LB process. In addition, the entire range of glass morphologies, ranging from open-pored to closed-melt configurations, could be analysed for the first time.

Porous glass (PG) particles are ideal supports in developing optical gas sensors as they combine fast mass transfer in macropores with large specific surface areas which are predestined for the deposition of indicator molecules. The well-established PG material is chemically stable and can be post-synthetically functionalized for introducing specific surface properties. Thus, surface functionalization with 3-mercaptopropyltrimethoxysilane (MPTMS) or 3-aminopropyl-triethoxysilane (APTES) provides the basis for the covalent coupling of the indicator molecule platinum(ii)-5,10,15,20-meso-tetrakis-(2,3,4,5,6-pentafluorophenyl)-porphyrin (PtTFPP) to the sensor matrix, reducing the risk of migration, aggregation, and leaching of the fluorescent dye. Nucleophilic substitution of a fluorine atom of the pentafluorophenyl PtTFPP groups by amino (APTES) and thiol (MPTMS) groups enables a covalent linkage of the oxygen indicator PtTFPP to the PG surface. The spectroscopic detection of the PtTFPP-silica bonding by solid-state 13C CP MAS NMR spectroscopy has turned out to be rather difficult due to very low indicator amounts. As an inexpensive alternative for PtTFPP, hexafluorobenzene C6F6 was used successfully for the spectroscopic proof of covalent bonds between fluorophenyl groups of an indicator dye and amino- or mercapto-silane cross-linker molecules. The PtTFPP/MPTMS- and the PtTFPP/APTES-modified PG sensor particles showed no leaching in organic solvents and have been applied for oxygen sensing up to oxygen pressures of 400 mbar pO2. The PG sensor particles show non-linear Stern-Volmer calibration plots and it has been found that the covalent bonding of PtTFPP via APTES linkage onto silica surfaces is better suited for various sensor applications.

The interplay between material structure, thermodynamics, and transport of confined fluids in nanoporous solids underpins their practical applications. Mesoporous networks embedded within microporous frameworks of zeolites and MOF materials are attracting increasing attention as they can enhance material properties and boost their performance. Correlating the mesoporous network structure with transport properties, however, remains challenging due to an apparent conflict: most thermodynamic models focus on single-pore equilibrium behavior, whereas transport is largely dictated by the organization of the pore network. Herein, we show that exploiting cooperative phenomena in gas adsorption governed by structural disorder resolves this challenge. We present a unified framework that links the structure, thermodynamics, and transport by leveraging recent advances in the statistical thermodynamic description of nonequilibrium-phase states arising from cooperativity across pore networks. Structural descriptors of the mesopore space, extractable from gas sorption measurements including, beyond conventional pore size distributions, the average pore connectivity and a hierarchy factor describing deviations from a fully random structure, are used to accurately predict diffusive transport. The framework's robustness is validated for mesoporous materials with both homogeneous and hierarchical pore architectures through experiments using transmission electron microscopy (TEM), mercury intrusion, and pulsed-field gradient (PFG) NMR.

Biodiesel was produced through transesterification from canola oil and methanol in the presence of silica xerogel derived from sugar cane leaves as a solid catalyst. The transesterification reaction was carried out at 65 °C in a batch-type reactor where a three-neck round-bottom flask was used as a reaction vessel with a reflux setup. Reaction time, methanol to oil ratio, and weight percentage of the catalyst were varied to optimize the biodiesel yield. The xerogel catalyst was characterized by inductively coupled plasma-optical emission spectroscopy (ICP-OES), nitrogen physisorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The produced biodiesel was characterized using gas chromatography-mass spectroscopy (GC-MS), Fourier transform infrared spectroscopy (FTIR), and a viscometer. The synthesized catalyst was found to operate as a true heterogeneous catalyst, since it preserved its solid nature and did not leach into the reaction medium. A biodiesel yield of 96.9% was achieved under optimal reaction conditions of 60 min reaction time, 6:1 methanol to oil ratio, and 3 wt % catalyst loading. The produced biodiesel was found to have a mixture of both saturated and unsaturated fatty acid methyl esters and had physical properties that met the ASTM and EN standards. The investigated catalyst was found to have a potential of being recycled up to 3 times, which positively affects the biodiesel production costs.

beta-wollastonite (beta-CaSiO3) microfibres were successfully synthesized using a one-step, template-free hydrothermal reaction involving calcium nitrate and sodium metasilicate in an alkaline medium. The synthesis of microfibres was completed at 220 degrees C within only 240 min under an autogenous pressure of 19 bar (1.9 MPa). This method avoids the formation of xonotlite as an intermediate phase, eliminating the need for subsequent calcination to achieve wollastonite. X-ray diffraction (XRD) confirmed the beta-wollastonite phase, while post-calcination analyses indicated enhanced crystallinity and structural characteristics. Scanning electron microscopy (SEM) revealed a needle-like morphology and N-2 adsorption-desorption analysis demonstrated a developed surface area of 26 m(2) g(-1) with notable mesoporosity. These advantageous features facilitated the integration of beta-wollastonite into the synthesis of a glass-ceramic composite, which was characterized for its morphological, structural, textural, and in vitro bioactivity properties. The composite was prepared by mixing beta-wollastonite and bio-active glass powders in a 1:4 mass ratio, followed by compaction through uniaxial pressing and sintering at 1000 degrees C for various time intervals. For comparison, compacted pure bioactive glass samples were also sintered under identical conditions. Structural, morphological, textural and in vitro bioactivity characterizations demonstrated that the incorporation of beta-wollastonite led to a more uniform and narrower pore size distribution and promoted neck formation between particles, indicating its potential for bone regeneration applications.

The properties of porous glasses and their field of application strongly depend on the characteristics of the void space. Understanding the relationship between their porous structure and failure behaviour can contribute to the development of porous glasses with long-term reliability optimized for specific applications. In the present work, we used X-ray computed tomography with nanometric resolution (nano-CT) to image a controlled pore glass (CPG) with 400 nm-sized pores whilst undergoing uniaxial compression in-situ to emulate a stress process. Our results show that in-situ nano-CT provides an ideal platform for identifying the mechanisms of damage within glass with pores of 400 nm, as it allowed the tracking of the pores and struts change of shape during compression until specimen failure. We have also applied computational tools to quantify the microstructural changes within the CPG sample by mapping the displacements and strain fields, and to numerically simulate the behaviour of the CPG using a Fast Fourier Transform/phase-field method. Both experimental and numerical data show local shear deformation, organized along bands, consistent with the appearance and propagation of +/- 45 degrees cracks.

This study explores the impact of pore volume distribution on the structural, thermal, and mechanical properties of spinodal phase-separated silica gels synthesized with poly(ethylene oxide) as a phase-separating agent. By systematically varying gelation temperatures between 20 and 60 °C, we investigate how reaction kinetics influence the resulting pore architecture, thermal conductivity, and elasticity. Nitrogen sorption, mercury intrusion porosimetry, and SEM analysis reveal a transformation from a bimodal pore structure at low temperatures, featuring interconnected macropores, to a predominantly mesoporous network with loss of bimodality. This shift in the diameter of the macropores significantly impacts the thermal insulation properties of the gels as thermal conductivity decreases from 68 to 27 mW (m·K)−1 due to reduced macroporosity, enhanced mesoporosity, and the Knudsen effect. Mechanical testing revealed a substantial decline in Young’s modulus with increasing gelation temperature. These changes are attributed to the interplay of mesoscale structural differences and density variations, driven by increasing gelation temperatures. While higher temperatures lead to reduced strut thickness and the loss of interconnected macropores, the substantial decline in Young’s modulus highlights the critical role of mesoscale structural integrity in maintaining mechanical stability. The findings underscore the importance of an optimized pore volume distribution in tailoring pore structure and performance characteristics, providing a pathway for optimizing silica gels for applications in thermal insulation, filtration, and catalysis.

Biodiesel was produced via transesterification of canola oil in the presence of a silica xerogel catalyst with deposited gold nanoparticles. The silica-gold catalyst was produced in situ, where gold metal was added to a sodium silicate solution; subsequently, gold nanoparticles were synthesised within the solution. The sodium silicate-gold nanoparticles solution was then turned into a silica-gold gel at pH 8.7 and later dried to form silica-gold nanoparticles xerogel. The produced silica-gold nanoparticles xerogel was characterised by X-ray diffraction (XRD), X-ray fluorescence (XRF), transition electron microscopy (TEM), and nitrogen physisorption. The gel had a silica content of 91.6 wt% and a sodium content of 6.4 wt%, with the added gold content being 99.5% retained. The biodiesel produced in the presence of silica-gold nanoparticles xerogel was characterised by gas chromatography-mass spectroscopy (GC-MS) and its physical properties, such as density, kinematic viscosity, flash point, pour point, and cloud point, were also determined. The silica-gold nanoparticles xerogel catalyst remained solid throughout its usage without leaching into the reaction medium. The produced biodiesel contained mostly monounsaturated fatty acid methyl esters and had a yield of 99.2% at optimum reaction conditions.

Transdermal Drug Delivery Systems (TDDS) show significant advantages over other forms of drug application. Despite their clinical use for decades, these drug delivery devices have yet to reach their full potential. While polymer matrices are most commonly used as transdermal patches so far, inorganic carriers like mesoporous silica membranes offer several advantages, including chemical stability and their tunable porous system, with adjustable pore sizes, pore volumes and surface chemistries. In this study, we chemically modified high and low porosity mesoporous silica membranes by post-synthetic methods and compared the effects of different surface modifications on loading efficacies and release profiles of different pharmacologically relevant drugs with different chemical properties. Drug loading capacities and release profiles were substantially affected by pore structure and surface modifcations with strongly acidic SO3H groups or hydrophobic methyl groups, while weakly acidic COOH groups or nitrile groups showed little effects. SO3H modification of low porosity (LP) membranes led to markedly increased loading capacity and a more sustained release profile of anastrozole. The latter was also observed for xylazine, but associated with lesser drug loading. Likewise, the SO3H modification also slowed down the release of imiquimod or flunixin. Increasing LP membrane hydrophobicity by methyl modification essentially abolished anastrozole drug loading. In high porosity (HP) membranes, effects of chemical surface modifications were overall weaker. This led to particularly slow anastrozole or xylazine release profiles from methyl-modified membranes. Biocompatibility studies showed some cell-inhibitory effects of CN functionalization, but full biocompatibility of SO3H functionalized membranes as indicated by efficient cell attachment and high viability. Both parameters, pore structure and chemical surface modifcations, drug-dependently affect drug loading and release properties. Since they can be precisely fine-tuned in mesoporous silica membranes, this allows for the development of optimized TDDS providing high drug loading and the desired release profile of a given drug. Our results presented here indicate that the SO3H modification is particularly useful in this regard.

Value added materials made from agricultural residues are very attractive since they contribute in reducing environmental waste and enhancing economic sustainability. Two deposition methods were investigated where silica xerogel from sugarcane leaves (a waste from sugarcane industry) was used as a support for the synthesized gold nanoparticles. Biogenic silica was refluxed with sodium hydroxide at 80 °C to form sodium silicate solution. The gold nanoparticles were either synthesized in the sodium silicate solution or separately to form silica/Au nanoparticles through a sol-gel method. Ultraviolet (UV)-visible spectroscopy, x-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray fluorescence spectroscopy (XRF), energy dispersive x-ray (EDX) and nitrogen adsorption-desorption were used to characterize the produced Si/Au nanoparticles. The two investigated methods resulted in distinctive deposition of gold nanoparticles on a silica xerogel support and also significantly different textural properties. The produced silica/gold nanoparticles had a Brunauer-Emmett-Teller (BET) surface area of up to 619 m2/g, pore diameter of 8.3 nm and pore volume of 1.28 cm3.g−1.

The present study investigated the adsorption of diclofenac sodium (DCF) and carbamazepine (CBZ) on carbon-silica composites (CSC), activated carbon (RH-AC) and biogenic silica (RH-BS) based on rice husks from aqueous solutions. The materials were characterised using scanning electron microscopy, infrared spectroscopy, inductively coupled plasma optical emission spectroscopy, nitrogen sorption and elemental analysis. These methods provided essential information on the morphology, chemical composition, textural properties and surface characteristics of porous materials. The results of the adsorption studies demonstrate that the investigated materials exhibit varying adsorption capacities for DCF and CBZ. The maximum adsorption capacity was achieved by CSCs, with 1111 mg g(-1) for DCF and 455 mg g(-1) for CBZ and indicates additive effects on the adsorption capacity of CSCs compared to RH-AC and RH-BS. In addition to the hydrogen bonds and the pi-pi electron donor-acceptor interactions of the carbon component, further hydrogen bonds are formed by the silanol groups of the silica component. The CSCs derived from rice husks represent an innovative approach to the more efficient removal of pharmaceutical residues from wastewater. This is accomplished by utilizing a single starting material for both components, thereby yielding a unique structural combination.

The development of non-precious metal-based electrodes that actively and stably support the oxygen evolution reaction (OER) in water electrolysis systems remains a challenge, especially at low pH levels. The recently published study has conclusively shown that the addition of haematite to H2SO4 is a highly effective method of significantly reducing oxygen evolution overpotential and extending anode life. The far superior result is achieved by concentrating oxygen evolution centres on the oxide particles rather than on the electrode. However, unsatisfactory Faradaic efficiencies of the OER and hydrogen evolution reaction (HER) parts as well as the required high haematite load impede applicability and upscaling of this process. Here it is shown that the same performance is achieved with three times less metal oxide powder if NiO/H2SO4 suspensions are used along with stainless steel anodes. The reason for the enormous improvement in OER performance by adding NiO to the electrolyte is the weakening of the intramolecular O─H bond in the water molecules, which is under the direct influence of the nickel oxide suspended in the electrolyte. The manipulation of bonds in water molecules to increase the tendency of the water to split is a ground-breaking development, as shown in this first example.