CO2 and N2 adsorption and separation using aminated UiO-66 and Cu3(BTC)2: A comparative study

Comparative study of synthesis methods and pH-dependent adsorption of methylene blue dye on UiO-66 and NH2-UiO-66

Metal-organic frameworks (MOFs) are highly promising adsorbents with notable properties such as elevated adsorption capacities and versatile surface design capabilities. This study introduces two distinct synthesis methods, one lasting 1 h and the other 24 h, for UiO-66 and NH2-UiO-66. While both methods yield structures with comparable crystallinity and morphology, the adsorption performance of the cationic methylene blue dye varies at different pH levels. Despite the 24 h synthesis time being optimal for maximum adsorption in both MOFs, the relative difference in NH2-UiO-66 adsorption percentage at different times suggests reduced dependency on synthesis time for this property. Notably, NH2-UiO-66 exhibits consistent and effective performance across three pH levels, warranting further investigation into its adsorption kinetics and isotherm. The achievement of high adsorption efficiency coupled with a significantly reduced synthesis time underscores the importance of developing simplified synthetic methods, essential for enhancing the practical applicability of MOFs in diverse applications.

Synthesis of Gingerol-loaded Uio-66 nanoparticles and its anti-cancer effect against gastric cancer cell line (AGS)

BACKGROUND

Gastric cancer is the world's fifth most prevalent cancer and its treatments are associated with issues. In this investigation, a UIO-66 nanoparticle was loaded with Gingerol (UIO-66-Gin) as a great drug carrier vehicle for chemotherapy of the AGS cancer cell lines.

METHODS AND RESULTS

UIO-66-Gin characterization was performed using SEM, DLS and FTIR tests. The release profile of Gin from UIO-66 was also assessed. The cytotoxicity of UIO-66-Gin against AGS cells was assessed using MTT assay. Caspase3, Caspase9, Bax, and Bcl2 genes expression was evaluated via Real-time PCR and apoptosis rate was performed using flow-cytometry assay. Size analysis indicated the spherical shape of nano-formulation with the mean size of 174.3 nm. Release analysis indicated that there was a 50% Gin release from the nanocarrier was reported in roughly 21 h, which revealed the regulated release of bioactive compound from the UIO-66 formulation in PBS medium. After 48 and 72 h, various concentration of both the Gin and UIO-66-Gin started to induce cytotoxicity in cancerous cells. However, the induction of cytotoxicity was higher in cells treated with UIO-66-Gin. UIO-66-Gin could induce the expression of pro-apoptotic (Bax, Caspase3, and Caspase9) genes and down-regulate the expression of Bcl2 as anti-apoptotic gene rather than other formulation. Flowcytometry results indicated that the elevation of apoptotic rate in cells treated with UIO-66-Gin was significantly higher than Gin treated cells.

CONCLUSIONS

Our investigation revealed the potent anticancer effect and apoptotic induction ability of UIO-66-Gin against cancerous cells through altering the expression of genes involved in apoptosis.

Carbon dioxide capture enhanced by pre-adsorption of water and methanol in UiO-66

The rapidly rising level of carbon dioxide in the atmosphere resulting from human activity is one of the greatest environmental problems facing our civilization today. Most technologies are not yet sufficiently developed to move existing infrastructure to cleaner alternatives. Therefore, techniques for capturing carbon dioxide from emission sources may play a key role at the moment. The structure of the UiO‐66 material not only meets the requirement of high stability in contact with water vapor but through the water pre‐adsorbed in the pores, the selectivity of carbon dioxide adsorption is increased. We successfully applied the recently developed methodology for water adsorption modelling. It allowed to elucidate the influence of water on CO₂ adsorption and study the mechanism of this effect. We showed that water is adsorbed in octahedral cage and stands for promotor for CO₂ adsorption in less favorable space than tetrahedral cages. Water plays a role of a mediator of adsorption, what is a general idea of improving affinity of adsorbate. On the basis of pre‐adsorption of methanol as another polar solvent, we have shown that the adsorption sites play a key role here, and not, as previously thought, only the interaction between the solvent and quadrupole carbon dioxide. Overall, we explained the mechanism of increased CO₂ adsorption in the presence of water and methanol, as polar solvents, in the UiO‐66 pores for a potential post‐combustion carbon dioxide capture application.

Amorphous mesoporous matrix from metal-organic framework UiO-66 template with strong nucleophile substitution

The metal-organic framework (MOF) UiO-66 is made of zirconium clusters coordinated with 1,4-benzenedicarboxylate linkers that is stable in water and is highly tolerant to extremely acidic or basic environments. Conversely, the zirconium clusters are affine to nucleophiles so the crystalline structures of UiO-66 can be converted into amorphous derivatives. In a mineral acid solution both protons and coordinating nucleophile are present. This study for the first time revealed that it is the strong nucleophile instead of proton deteriorate the crystalline structures of UiO-66. Also, the so-produced amorphous mesoporous matrix, if not totally dissolved, can be applied as an efficient adsorbent. The noted adsorption capabilities of Cu(II) and nucleophiles by these amorphous mesoporous matrix did not correlate with the structural crystallinity or the internal surface area; conversely, the doped nucleophiles were noted to contribute to the adsorption tendencies towards Cu(II) and phosphate species via electrostatic interactions and hydrogen bonding, respectively. Conversion of sacrificing UiO-66 template to amorphous matrix can be applied as an effective way to fabricate specific adsorbent with resistance to extreme pH and strong nucleophile challenges.