In this study, we conducted a comprehensive investigation relating to the efficiency of the Al-MOF CAU-10 as a sorbent in a Sorption Enhanced Reaction Process (SERP) based on its hydrophilic/hydrophobic balance. We confirmed both experimentally and through simulation that CAU-10 is a hydrophobic material at low pressure, whereas it shows a high affinity for methanol. The cosorption of water and methanol shows that both molecules are in competition, mostly for the oxygen atoms of the ligands. An important result is the influence of the relative pressure of the vapor mixture on the composition of the adsorbed phase. At low relative pressure, methanol is mostly adsorbed from the mixture, while water is only adsorbed from 0.16 p/p°. At higher relative pressures, water becomes predominant in the adsorbed phase. We therefore took advantage of this result to improve the catalytic reduction of CO2 into methanol by sorption of methanol or water. The catalytic test was performed at 270 °C under a total pressure of 50 bar. Under these conditions, the methanol yield increased by more than 6% compared to a catalytic reaction performed without sorbent, thus validating our fundamental approach.

Gold-mesoporous silica (Au@mSiO2) core-shell nanoparticles (NPs) hold great promise for application in nanomedicine, as they enable the photostimulated release of guest molecules located within their pores. In this study, prioritizing the achievement of atom economy, we used a one-pot synthesis protocol, to produce core-shell Au@mSiO2 NPs from a properly defined precursor state. Upon sodium hydroxide addition, the formation of gold NPs occurs quickly, followed by the formation of a silica shell, eliminating the need to isolate the gold cores. We conducted a comprehensive mechanistic analysis that elucidates the relative kinetics of gold and silica formation, identifying key factors for fine-tuning NPs within the size range of 50 to 100 nm, ideal for biological applications. The photothermal properties of such Au@mSiO2 were characterized and modelled. Under the experimental conditions typically used for cargo release experiments, the model predicts a temperature increase for a single particle of less than 10^(-4) °C, demonstrating that the release is due to the collective heating of the medium by a myriad of NPs rather than by the temperature elevation of individual NPs under irradiation. Overall, the studies developed here will enable more effective design and preparation of Au@mSiO₂ particles, optimizing them for a broad range of photothermal applications.

We present an innovative template-free water-based sol-gel method to produce uniform mesoporous silica beads of millimeter size, which have tunable size, stiffness and porosity, and could be used for adsorption applications. Our protocol exploits an in-situ enzymatic reaction to produce spherical beads of hydrogel from a charge-stabilized suspension of silica nanoparticles confined in a millimetric drop suspended in a non-miscible oil. Once the gelation step is complete, the spherical bead of gel is cleaned from oil and deposited onto a hydrophobic surface and let dry. Separating the gelation to the drying steps ensures a spatially uniform gel and allows us to perform a solvent exchange before drying. For all beads, we observe a crack-free drying process leading to the formation of stiff quasi-spherical beads with diameter in the range 1 to 5 mm and Young modulus in the range $(0.1-2)$ GPa and narrow pore size distribution, centered around $10$ to $25$ nm depending on the experimental conditions. Finally, to demonstrate the potentiality of these materials, we graft on the bead surface aminosilane molecules, and quantify their CO$_2$ adsorption efficiency. Overall, the production method we have developed is simple, readily adaptable, and offers promising materials for adsorption, storage, catalysis and chromatography.

Gold-mesoporous silica (Au@mSiO2) core-shell nanoparticles (NPs) have shown interesting potential for the loading of molecules to be delivered by plasmonic heating. In this study, we describe the unprecedented synthesis of Au@mSiO2 NPs with large pores (lp-Au@mSiO2), aiming at encapsulating large biomolecules such as proteins. Starting from recently reported Au@mSiO2 seeds with a diameter of 45 nm, two strategies are presented to grow a mesoporous shell with large pores. The most interesting NPs (lp-Au@mSiO2) were obtained with the biphasic stratification approach, yielding NPs with large conical pores (10-20 nm openings), characterized in depth by N2-sorption and electron microscopies. Atomic force microscopy (AFM) with a sharp tip was used for the first time with these mesoporous materials to probe the accessibility of the pore openings. Biphasic stratification provides NPs with good colloidal and hydrolytic stabilities in aqueous saline medium (PBS) allowing the incubation of these NPs with two model proteins: horse radish peroxidase (HRP) and red fluorescent protein (RFP). lp-Au@mSiO2 exhibit a significantly larger loading capacity with respect to NPs with similar diameter, either non-porous or with narrower pores, providing evidence that the proteins can indeed be encapsulated within the pores.

MOF CALF-20 has been employed in industry due to its hydrophobic properties, which are conducive to CO2 capture. Nevertheless, additional characteristics of this porous material are worthy of investigation, including its mechanical properties and flexibility. When CALF-20 is subjected to water vapor, it exhibits a slight contraction, which may be attributed to its hydrophobic nature. Conversely, when CALF-20 adsorbs methanol, it exhibits a 30 % increase in volume. Furthermore, our findings indicate that the interactions between MOFs and water or methanol are dependent on the crystalline phase. The aforementioned interactions exhibit a range of values between-37.8 and-54 kJ mol-1 in the case of water, whereas they consistently approach-53 kJ mol-1 in the case of ethanol, irrespective of the crystalline phase. This has significant implications for methanol adsorption in water-saturated CALF-20. Our findings suggest that the water confined in the pores can be pushed out by the methanol flow, whereas this phenomenon does not occur in the case of water adsorption in CALF-20 that has already been filled with methanol. These findings pave the way to improvements in Sorption-Enhanced Reaction Process technology for pure methanol production from carbon dioxide, where selective sorbents are required for shifting the methanol production equilibrium.

Hollow mesoporous organosilica (HMO) nanoparticles with a controlled core cavity and a mesoporous organosilica shell are elaborated using coupled hard and soft templating approaches. A dense silica hard template is first synthesized following the classical St & ouml;ber sol-gel protocol. The hybrid silica shell is then deposited through the co-condensation of an organosilane precursor with surfactant. HMO-NPs are obtained after the removal of the hard and soft templates. In this study, we demonstrate that this strategy can be applied to synthesize HMO-NPs of different sizes. We present a multiscale approach for a step-by-step characterization of synthesis stages, the structural organization of the PMO shell, and its properties. Particular emphasis is placed on the removal of the silica hard template step. A protocol is proposed to assess the efficiency of the etching process and estimate any remaining silica using infrared spectroscopy. Finally, from the perspective of potential medical applications, preliminary tests on endocytosis and biocompatibility are presented and yield promising results.

This study examines the adsorption properties of MIL-120(Al) for pure vapour-phase sorbates (water and methanol) and their mixtures, with a particular focus on the material's selectivity influenced by relative pressure. The selected MOF presents 1-D channels of similar to 3.5 x 6 angstrom(2) aperture, associated with a specific surface area of 350 m(2)/g and a pore volume of 0.26 cm(3)/g. Adsorption isotherms at 25 degrees C, supported by Grand Canonical Monte Carlo (GCMC) simulations, revealed a high affinity of MIL-120(Al) for water and methanol at relative pressures lower than 0.2. However, methanol was identified as the preferred adsorbate at these low relative pressures in water-methanol mixtures. This selectivity, confirmed by GCMC, showed that the composition of the adsorbed phase was made of 90 % of methanol, regardless of the equilibrium vapour phase composition. In contrast, at higher relative pressures, the selectivity of MIL-120(Al) shifted markedly towards water, thereby highlighting the sensitivity of MIL-120(Al) to relative pressure in competitive adsorption scenarios. At high relative pressure, the composition of the adsorbed phase was found to be more than 95 % molar of water, even for vapours mixtures made of 50 % methanol. These findings contribute valuable insights into the design of pressure-sensitive adsorption systems for industrial applications such as sorption enhanced reaction production (SERP) technology.

The development of structured hybrid materials with calibrated nanopores and homogeneous functionalization is crucial for enzyme encapsulation with optimal loading efficiency and specific activity. This work showcases the encapsulation of horseradish peroxidase (HRP) via the direct synthesis of functional nanopores with diameters spanning from 4 to 31 nm, by employing polyion complex (PIC) micelles as structure-directing and -functionalizing agents for silica. Micelle size was controlled by reversible addition-fragmentation chain transfer (RAFT) synthesis of double-hydrophilic block copolymers (poly(oligo(ethylene glycol)methyl ether acrylate)-block-poly(acrylic acid), POEGMEA n -b-PAA m ): The hydrodynamic diameter of the PIC micelles scales with the copolymer length, and the nanopore size in silica materials is proportional to the micelle core. These well-calibrated nanopores benefit from intrinsic and uniform acrylic acid functionality (close to 1.9 mmolacrylic acidgSiO2 -1), which allows elucidation of their structure-activity relationship in terms of HRP encapsulation and specific activity. The loading capacity was optimal for pore diameters of about 9-17 nm, reaching about 35 mggmaterial -1. The lower loadings obtained for smaller and larger pores indicate mass transfer and low specific area limitations, respectively. Nanopores larger than the hydrodynamic diameter of the enzyme are required to maintain the specific activity of HRP. The highest enzyme activity achieved (ca. 1200 Ugmaterial -1) was competitive with the literature and corresponded to materials with a pore diameter of 17 nm. This optimized functional nanopore size exceeds the hydrodynamic diameter of the enzyme, facilitating mass transfer and preserving its specific activity, while also being sufficiently small to maximize the available functional surface area.

Adsorption isotherms of pure vapors and vapor mixtures of water, methanol, and cyclohexane were studied using a synthesized 13X zeolite (FAU topology), by means of a DVS gravimetric vapor analyzer. These results were validated by GCMC calculations. The surface chemistry of the adsorbent was characterized by the thermodesorption of ammonia, and its textural properties were studied using nitrogen physisorption. The 13X zeolite was found to be strongly acidic (BrØnsted acid sites, Si/Al = 1.3) and its specific surface area around 1100 m2·g−1. Water was found to be able to diffuse within both the supercages and the sodalite cavities of the FAU structure, whereas methanol and cyclohexane were confined in the supercages only. The water/methanol sorption selectivity of the 13X zeolite was demonstrated by co-adsorption measurements. The composition of the water/methanol adsorbed phase could be calculated by assuming IAST hypotheses. This model failed in the case of the water/cyclohexane co-adsorption system, which is in line with the non-miscibility of the components in the adsorbed state. The sorption isotherms could be successfully simulated, confirming the robustness of the forcefields used. The 13X zeolite confirmed its a priori expected hydrophilic nature, which is useful for the selective adsorption of water in a methanol–water vapor mixture.

CH 3 -functionalised imogolite nanotubes form extended bundles and the accessibility of their porous structure may vary depending on the surrounding medium.

Mesoporous Silica Nanoparticles (MSNs) have been increasingly investigated as versatile drug delivery carriers. A particular challenge for the systemic use of MSNs lies in the control of their degradation, which has not been fully understood until now. We implemented standard dynamic light scattering (DLS) experiments and introduced a novel DLS technique in a confocal volume to track the dynamics of large-pore MSN degradation in situ. This unique DLS technique, which involves a small observation volume, was chosen for its ability to count particle by particle during the degradation process, a method that has not been commonly used in nanoparticle research. The experiments were performed in different media compositions at low particle concentrations, below the silica solubility limit. MSNs with large conical pores were prepared and studied as they offer the possibility to incorporate and release large-sized biomolecules. Large-pore MSNs followed a singular degradation mechanism following a stochastic-like behavior, a finding that challenges the common idea that all nanoparticles (NPs) degrade similarly and homogeneously over time. We showed that some NPs are observed intact over a prolonged period while most other NPs have already vanished or been transformed into swollen NPs. Thus, a heterogeneous degradation process occurs, while the total concentration of NPs undergoes an exponential decay. These large conical pores MSNs will be utilized as reliable biomolecule nanocarriers by predicting the factors underlying the NP hydrolytic stability.

Abstract Water is a universal solvent and swelling agent that is widely used in wood industry in association with organic solvents and salts, whether for the fractionation of biomass and the production of bio-based synthons for the chemical industry, the application of sizing agents and painting for the paper industry, or the incorporation of preservatives to enhance wood durability for the timber industry. The relevance of solvents and technical treatments used for wood-based products requires a proper identification of the specific role of each solvent on wood biopolymers to better understand and predict their influence on wood properties. In particular, wood impregnated with aqueous solutions of organic solvents have shown to give rise to greater swelling than that observed in pure water, described as “hyperswelling”. To understand this phenomenon, the first step is to examine the existing interactions between wood microstructure and the different solvents present in these mixtures. This study is an attempt to bring to light the sorption behaviour of four different hardwoods in water–ethanol vapour mixtures containing increasing molar fractions of ethanol from 0 to 100%. Contrasted sorption behaviour in pure solvents were observed according to wood species having different biochemical composition. This behaviour highlights the different affinities of ethanol and water for the macromolecules present in the wood microstructure. With mixed solvents, peculiar effects were confirmed in sorption behaviour of woods with lower mixed solvent uptake at high partial pressures compared to pure solvents. It is also shown that part of the sorbed ethanol molecules remains chemisorbed in the wood structures at the end of the desorption process.

Water is a universal solvent and swelling agent that is widely used in wood industry in association with organic solvents and salts, whether for the fractionation of biomass and the production of bio-based synthons for the chemical industry, the application of sizing agents and painting for the paper industry or the incorporation of preservatives to enhance wood durability for the timber industry. The relevance of solvents and technical treatments used for wood-based products requires a proper identification of the specific role of each solvent on wood biopolymers to better understand and predict their influence on wood properties. In particular, wood impregnated with aqueous solutions of organic solvents has shown to give rise to greater swelling than that observed in pure water, described as “hyperswelling”. To understand this phenomenon, the first step is to examine the existing interactions between wood microstructure and the different solvents present in these mixtures. This study is an attempt to bring to light the sorption behaviour of four different hardwoods in water–ethanol vapour mixtures containing increasing molar fractions of ethanol from 0 to 100%. Contrasted sorption behaviour in pure solvents was observed according to wood species having different biochemical compositions. This behaviour highlights the different affinities of ethanol and water for the macromolecules present in the wood microstructure. With mixed solvents, peculiar effects were confirmed in sorption behaviour of woods with lower mixed solvent uptake at high partial pressures compared to pure solvents. It is also shown that part of the sorbed ethanol molecules remains chemisorbed in the wood structures at the end of the desorption process.

Despite the interest in proton exchange membrane (PEM)technologies(fuel cells and electrolyzers) for energy applications, the low stabilityof the electrolyte materials under working conditions (i.e., humidityand temperature) is one of their major limitations. Metal-organicframeworks (MOFs) have recently emerged as promising electrolytesdue to their higher stability compared with the currently appliedorganic polymers, proton conductivity, and outstanding porosity. Here,a novel robust Bi phosphonate MOF (branded as IEF-7) was successfullysynthesized and fully characterized, exhibiting an unusual topologydue to the irregular coordination geometry of the bismuth cations.Furthermore, IEF-7 exhibited potential porosity, very high chemicaland thermal stability, and free -PO3H groups involvedin its ultrahigh proton conductivity, reaching 1.39 x 10(-2) S cm(-1) at 90 degrees C and 90% relativehumidity for, at least, 3 cycles. In order to improve the consolidationand shaping of the powder for testing its ion conductivity properties,a highly MOF-loaded composite (90 wt %) was prepared by adding a protonconductive sulfonated polysulfone binder. The proton conductivityof the resulting composite was in the same order of magnitude as thecompacted MOF powder, making this polymeric composite electrolytevery promising for PEM technologies.

The synthesis of various periodic mesoporous organosilica nanoparticles (nanoPMOs) from the corresponding organo-bridged bis(triethoxy)silanes is described. A strong influence of the sodium hydroxide concentration is observed, leading to various sizes or morphologies depending on the precursor. In particular, in the case of the ethenylene linker, the morphology evolves from small flakes to elongated particles, while in the case of the phenylene precursor, small well-organized arms start to form at high base concentration. A mechanistic study shows that in all cases the nanoparticles nucleate before the condensation reaction commences and at very low conversions of the hydrolysis reaction of ethoxysilanes. The resulting hybrid nanoPMOs were compared for their adsorption properties towards rhodamine B (RB), which highlights large differences between the nanoPMOs with different linkers, and evidences a very strong affinity of the phenylene PMO with the poly-aromatic dye. Similarly, the sorption of cyclohexane and water revealed a much higher lipophilicity of the phenylene-bridged nanoPMO compared to the other studied linkers, despite a similar hydrophilicity. These results should help to better design nanoPMOs as nanovectors for drugs.

Monodispersed hollow periodic mesoporous organosilica nanoparticles (HPMO-NPs) with a controlled core cavity and a periodic mesoporous organosilica (PMO) shell are successfully synthesized using a dual templating approach. The PMO shell synthesized by the sol–gel route exhibits a hybrid organic-inorganic framework based on phenylene bridges. The HPMO spherical nanoparticles with a diameter above 500 nm were characterized using a multiscale approach through TEM, BET, SAXS, and FT-IR. They are shown to offer an open periodic mesoporosity, a hollow cavity with a size tailored by the diameter of the core template, and finally, a high surface area (833 m2 · g−1). In addition, we demonstrate that, through the same approach, the size of these hollow spherical nanoparticles can be tuned. Indeed, sub-50-nm hollow nanoparticles with mesoporous shells have also been obtained. The differences observed in the textural properties of these two sizes of hollow mesoporous nano-objects are discussed.

(1) Background: Due to human activities, greenhouse gas (GHG) concentrations in the atmosphere are constantly rising, causing the greenhouse effect. Among GHGs, carbon dioxide (CO2) is responsible for about two-thirds of the total energy imbalance which is the origin of the increase in the Earth’s temperature. (2) Methods: In this field, we describe the development of periodic mesoporous organosilica nanoparticles (PMO NPs) used to capture and store CO2 present in the atmosphere. Several types of PMO NP (bis(triethoxysilyl)ethane (BTEE) as matrix, co-condensed with trialkoxysilylated aminopyridine (py) and trialkoxysilylated bipyridine (Etbipy and iPrbipy)) were synthesized by means of the sol-gel procedure, then characterized with different techniques (DLS, TEM, FTIR, BET). A systematic evaluation of CO2 adsorption was carried out at 298 K and 273 K, at low pressure. (3) Results: The best values of CO2 adsorption were obtained with 6% bipyridine: 1.045 mmol·g−1 at 298 K and 2.26 mmol·g−1 at 273 K. (4) Conclusions: The synthetized BTEE/aminopyridine or bipyridine PMO NPs showed significant results and could be promising for carbon capture and storage (CCS) application.

The objective of this work is to evaluate methyl ester alginates and alginic acid (AA) as moisture-scavenging excipients for the formulation of aspirin tablets obtained by direct compression. The tablets were stored at accelerated conditions (40 °C/75 % RH) and assessed for changes in tensile strength, mass, thickness and disintegration time. While moisture caused a reduction in the hardness of MCC and AA tablets, hardness of the tablets made from methylated materials was virtually unaffected. The physical stability of alginate ester tablets was found to be related to their increased plastic deformation leading to extended interparticle contact with less impact on tablet porosity. Finally, the combination of higher moisture affinity and lower water dissociation exhibited by alginates esters resulted in tablets with the lowest aspirin degradation. These findings suggest that excipients with high water retention can act as moisture-scavengers without losing their functional properties and reducing the degradation of moisture-sensitive drugs.