The current study presented a porous liquid (PL) prepared from propylene glycol-based deep eutectic solvent (DES) and hyper-crosslinked polymers (HCP) that are liquids over wide temperature ranges, including ambient temperature. It was shown that the solvent molecules are too large to penetrate the pores of HCP, so the PL is maintained as a suspension with permanent free volume for several months and can absorb large amounts of gases. This study marks the pioneering use of DESs as the liquid medium, replacing ionic liquids due to their closely matched properties. The structural features of both DES and HCP are retained; the increase in CO2 absorption capacity compared to pure DES is due to the presence of a porous solid and is proportional to the amount of solid. The absorbed CO2 amount rises from 1.0105 mmol·g−1 in pure DES to 1.3232, 1.6027, and 1.2168 mmol·g−1 in PL-1, PL-2, and PL-3, respectively. Thermodynamic analysis revealed that the enthalpy of gas absorption allows straightforward regeneration of the PLs in the studied cases. The investigated PLs show great potential as gas absorbents, with the incorporation of just 0.5 wt% of porous polymer material leading to an impressive increase in solvent absorption capacity, up to 59 %.

Population growth in recent years has led to increased wastewater production and pollution of water resources. This situation also heavily affects Bolivia, so wastewater treatment methods and materials suitable for Bolivian society should be explored. This study investigated the natural Bolivian Zeolite (BZ) and its NaCl-modified structure (NaBZ) as adsorbents for cadmium removal from water. The natural BZ and the modified form NaBZ were investigated by different physicochemical characterization techniques. Furthermore, XPS and FT-IR techniques were used to investigate the adsorption mechanisms. The cadmium adsorption on BZ and NaBZ was analyzed using various mathematical models, and the Langmuir model provided a better description of the experimental adsorption data with cadmium adsorption capacities of 20.2 and 25.6 mg/g for BZ and NaBZ, respectively. The adsorption followed the pseudo-second order kinetics. The effect of different parameters, such as initial cadmium concentration and pH on the adsorption was studied. In addition, the results of the regeneration test indicated that both BZ and NaBZ can be regenerated by using hydrochloric acid (HCl). Finally, the adsorption experiment of BZ and NaBZ on a real water sample (brine from Salar de Uyuni salt flat) containing a mixture of different heavy metals was carried out. The results obtained in this study demonstrate the effectiveness of natural BZ and modified NaBZ in the removal of heavy metals from wastewater.

Binary and ternary composites of BiOI with NH2-MIL-101(Fe) and a functionalized biochar were synthesized through an in situ approach, aimed at spurring the activity of the semiconductor as a photocatalyst for the removal of ciprofloxacin (CIP) from water. Experimental outcomes showed a drastic enhancement of the adsorption and the equilibrium (which increased from 39.31 mg g–1 of bare BiOI to 76.39 mg g–1 of the best ternary composite in 2 h time), while the kinetics of the process was not significantly changed. The photocatalytic performance was also significantly enhanced, and the complete removal of 10 ppm of CIP in 3 h reaction time was recorded under simulated solar light irradiation for the best catalyst of the investigated batch. Catalytic reactions supported by different materials obeyed different reaction orders, indicating the existence of different mechanisms. The use of scavengers for superoxide anion radicals, holes, and hydroxyl radicals showed that although all these species are involved in CIP photodegradation, the latter play the most crucial role, as also confirmed by carrying out the reaction at increasing pH conditions. A clear correlation between the reduction of BiOI crystallite sizes in the composites, as compared to the bare material, and the material performance as both adsorbers and photocatalyst was identified. 

Most pulmonary drugs are immediate-release formulations with short duration of action. Controlled release systems provide the ability to deliver drugs at a controlled rate, which helps maintain drug concentrations within the therapeutic window for a longer period of time. This study aimed to produce microparticles (MPs) of hyaluronic acid hydrogel (HAGA) loaded with salbutamol sulphate (SS) for controlled release in the lung. The drug-loaded MPs were prepared via spray drying and underwent extensive characterization, which revealed that SS was successfully encapsulated in the HAGA matrix. The prepared MPs (denoted as HASS) ranged in size from 1.6 ± 0.4 μm to 1.7 ± 0.5 μm with a fine particle fraction (FPF) of 48–56% and showed improvement in aerodynamic properties compared to unloaded HAGA hydrogel MPs. In vitro drug release studies performed in a Transwell system confirmed the potential of the particles to release the drug in a sustained manner. The drug release was delayed for all formulations, with a t₆₃ between 5 and 30 min, compared to <1min for pure SS. This study advances our understanding of the formulation of a highly soluble drug to achieve controlled release in the lung.

In this report, 1-ethyl-3-methylimidazolium acetate, [EMIM][AcO] ionic liquid (IL) and acetic acid (AA) comprised solvents were used for the thermal treatment of poly (vinylidene difluoride), PVDF. Here, besides the various combinations of IL and AA in solvents, the pure IL and AA were also applied as a solvent upon thermal treatments. The samples obtained after the treatment were analysed for structural and crystalline phase changes, porosity, and molecular weight distribution with various analytical techniques. The Kamlet-Taft parameters measurement of the IL and AA containing solvents with different solvatochromic dyes was also performed to examine their solvent properties and correlate with the properties of the treated PVDF materials. The treatment of PVDF with pure IL results in the formation of highly carbonaceous material due to extensive dehydroflurination (DHF) as well as possibly successive cross-linking in the polymer chains. Upon IL and AA combined solvent treatment, the neat PVDF which composed of both α- and β crystalline phases was transformed to porous and β-phase rich material whereas in case of pure AA the non-porous and pure α-phase polymeric entity was obtained. A combined mixture of IL and AA resulted in a limited the DHF process and subsequent cross-linking in the polymer chains of PVDF allowed the formation of a porous material. It was observed that the porosity of the thermally treated materials was steadily decreasing with increase in the amount of AA in solvents composition and solvent with an AA:IL mole ratio of 2:1 resulted in a PVDF material with the highest porosity amongst the applied solvents. A recovery method for the IL and AA combined solvent after the thermal treatment of PVDF was also established. Hence, with varying the type of solvents in terms of composition, the highly carbonaceous materials as well as materials with different porosities as well as crystalline phases can be obtained. Most importantly here, we introduced new IL and AA containing recoverable solvents for the synthesis of porous PVDF material with the electroactive β-phase.

Herein, we report porous ionic liquids (type-III) designed to utilize microporous ZIF-8 moieties with functional ionic liquids such as 8-(2-methoxyethyl)-1,8-Diazabicyclo[5.4.0]undec-7-en-8-ium, Bis(trifluoromethane)sulfonamide ([MEDBU][TFSI] and Trioctylammonium 4-para-tert-butylbenzoiate [TOAH][PTBBA]). The prepared materials were thoroughly characterized by means of XRD, FT-IR, SEM, TEM, BET, TGA, DSC and viscometry techniques. The idea of combining the intrinsic properties of ionic liquids with microporous architecture to prepare porous ionic liquids yields promising fluidic materials that have received attention in industrial applications such as gas sorption and separation etc. The prepared porous ionic liquids possess unique physico-chemical properties such as low viscosity, high thermal stability, low vapor pressure, reusability and their fluidic nature renders the materials suitable for CO2 capture. Herein introduced porous ionic liquids (ILs) showed enhanced CO2 uptake (0.92 mmol/g in [TOAH][PTBBA]-Z100 and 1.16 mmol/g in [MEDBU][TFSI]-Z200), or in other words, 15–47% higher sorption capacity compared to neat ionic liquids. This concept overcomes the drawbacks of highly viscous ILs and their limited CO2 sorption capacity. Thermodynamic modeling further demonstrated that the enthalpy of sorption is only −9.99 kJ mol−1, indicating that significantly less energy is required for regeneration. This is promising for the potential use of these fluidic materials in continuous separation processes on an industrial scale, as a better alternative to the existing hazardous amine scrubbing.

Valorization of renewable and biodegradable biopolymers to value added chemicals and green fuels is currently considered as an important research topic aiming at reducing the dependency on fossil derived feedstocks as well as their negative consequences on the environment. In this report, we are introducing an ionic liquid (IL) mediated, sustainable, and green synthesis of crotonic acid (CA) from poly-(3-hydroxybutyrate, PHB), a biopolymer derived from microbial fermentation. In this actual case, imidazolium cation comprising ILs have been used in the synthesis, where the influence of various reaction parameters such as reaction temperature and types of ILs as well as the amount of polymer, water, and IL in the reaction mixture were examined. The conversion of PHB to CA in IL took place by a base catalyzed depolymerization with formation of crotonyl terminated polymeric entities as intermediates, a mechanism that was confirmed by NMR analysis of the reaction mixtures sampled when the reactions were carried out at various temperatures. The rate of CA formation via the IL mediated base catalyzed depolymerization increased with increasing temperature in the tested interval, and 97% yield of CA was obtained after 90 min at 140 degrees C. The [EMIM][AcO] IL applied as solvent and catalyst is capable of completely depolymerizing PHB to CA in 5 h at 120 degrees C up to a polymer loading of 40 wt%. At higher loadings the depolymerization became incomplete, which is attributed to a deactivation of the IL due to hydrogen bonding interactions with the in situ formed CA, confirmed by NMR and DSC techniques. Since the depolymerization is base catalyzed, the only tested ILs that were able to form CA were based on acetate anions, whereas the less basic or neutral [EMIM][Cl] IL was found to be inactive. Finally, more than 90% of CA as well as [EMIM][AcO] IL were recovered in high purity by solvent extraction with brine (saturated aqueous NaCl) and 2-methyl tetrahydrofuran (2-Me-THF). Most importantly, here we introduce a sustainable, metal free, and single solvent based reaction approach for selective depolymerization of PHB to industrially valuable CA in basic and recoverable ILs.

We investigate the performance of four Prussian blue analogues (PBAs) as catalysts for the selective degradation of ciprofloxacin in water, under both dark and illumination conditions. We show that no light is actually needed to induce a selective degradation of the molecular target, while light irradiation spurs the process, without, however, resulting in the commonly reported photolysis-supported breaking down. We present a systematic characterization of the PBAs aiming at interpreting the catalytic outcomes in the light of a classic coordination chemistry analysis, empowered by the most recent findings in literature. We show that varying the transition metal binding the N atom of the cyanide bridge is key to promote photoinduced charge generation and transfer, which effectively disrupts the molecular target. The analysis of the materials before and after the irradiation with solar simulated light results in a change of the lattice parameters, indicating the possibility of a light-induced spin cross-over.

Hydrogels warrant attention as a potential material for use in sustained pulmonary drug delivery due to their swelling and mucoadhesive features. Herein, hyaluronic acid (HA) is considered a promising material due to its therapeutic potential, the effect on lung inflammation, and possible utility as an excipient or drug carrier. In this study, the feasibility of using HA hydrogels (without a model drug) to engineer inhalation powders for controlled pulmonary drug delivery was assessed. A combination of chemical crosslinking and spray-drying was proposed as a novel methodology for the preparation of inhalation powders. Different crosslinkers (urea; UR and glutaraldehyde; GA) were exploited in the hydrogel formulation and the obtained powders were subjected to extensive characterization. Compositional analysis of the powders indicated a crosslinked structure of the hydrogels with sufficient thermal stability to withstand spray drying. The obtained microparticles presented a spherical shape with mean diameter particle sizes from 2.3 ± 1.1 to 3.2 ± 2.9 μm. Microparticles formed from HA crosslinked with GA exhibited a reasonable aerosolization performance (fine particle fraction estimated as 28 ± 2%), whereas lower values were obtained for the UR-based formulation. Likewise, swelling and stability in water were larger for GA than for UR, for which the results were very similar to those obtained for native (not crosslinked) HA. In conclusion, microparticles could successfully be produced from crosslinked HA, and the ones crosslinked by GA exhibited superior performance in terms of aerosolization and swelling.

Oral films (OFs) continue to attract attention as drug delivery systems, particularly for pedatric and geriatric needs. However, immiscibility between different polymers limits the full potential of OFs from being explored. One example is pullulan (PUL), a novel biopolymer which often has to be blended with other polymers to reduce cost and alter its mechanical properties. In this study, the state-of-the-art in fabrication techniques, three-dimensional (3D) printing was used to produce hybrid film structures of PUL and hydroxypropyl methylcellulose (HPMC), which were loaded with caffeine as a model drug. 3D printing was used to control the spatial deposition of films. HPMC was found to increase the mean mechanical properties of PUL films, where the tensile strength, elastic modulus and elongation break increased from 8.9 to 14.5 MPa, 1.17 to 1.56 GPa and from 1.48% to 1.77%, respectively. In addition, the spatial orientation of the hybrid films was also explored to determine which orientation could maximize the mechanical properties of the hybrid films. The results revealed that 3D printing could modify the mechanical properties of PUL whilst circumventing the issues associated with immiscibility.