Due to the diseases that people face today, scientists dedicate a part of their research to the synthesis, characterization, and study of functional compounds for controlled drug delivery. On the one hand, resorcinarenes are macrocycles obtained by condensation reactions of resorcinol and aldehyde. They include an upper and a lower rim functioning with different groups that confer solubility to the macrocycle and favor interactions with other compounds, therefore the hydroxyl groups on the upper rim improve the formation of hydrogen bonds. Additionally, resorcinarenes feature a cavity studied for forming host-guest complexes. SBA-15, on the other hand, is a mesoporous silica characterized by ordered pores in its structure and a large surface area. As a result of its properties, it has been used for several purposes, including absorbents, drug delivery, catalysis, and environmental processes. This review shows the recent advances in synthesis methods, characterization, micelle formation, interaction with other compounds, and host-guest procedures, as well as techniques for evaluating toxicity, drug retention, and their preliminary uses in pharmacology for macrocycles, such as resorcin[4]arenes and SBA-15.
Smoked cigarette butts (SCB) can serve as precursors for producing activated carbon (AC) due to their high carbon content, which originates from cellulose acetate and other components retained during tobacco combustion. This study examines the pyrolysis process and char formation from SCB residue. Kinetic analysis of char formation is conducted using thermogravimetry with heating rates of 5, 10, and 15 °C/min. Mathematical models, including Kissenger-Akahira-Sunose (KAS), Starink (STK), and Ozawa-Flynn-Wall (OFW) are applied to determine thermodynamic parameters, such as activation energy. The resulting char undergoes KOH activation to enhance surface area and pore volume, resulting in BET surface area and micropore volume values of 433 m2/g and 0.25 cm3/g, respectively. The activated carbon is then used for Cr(VI) removal, exhibiting a maximum adsorption capacity (Qmax) of 55.8 mg/g, as determined by the Langmuir model.
Smoked cigarette butts (SCB) can be used as precursors to obtain activated carbon (AC) due to their high carbon content related to the presence of cellulose acetate and components that are retained in the tobacco combustion process. In this way, it was analyzed how the process of pyrolysis or formation of char from this residue occurs, for this a study of the kinetics of formation of char is carried out by thermogravimetry, using three heating speeds 5, 10 and 15 °C/min. Based on the data obtained, mathematical models such as Kissenger - Akahira - Sunose (KAS), Starink (STK) and Ozawa - Flynn - Wall (OFW) were used in order to identify thermodynamic parameters through the energy of activation. The char obtained was subjected to an activation treatment with KOH in order to increase the surface area and pore volume, obtaining values of 433 m2/g of BET area and 0.25 cm3/g of micropore volume. Finally, the adsorbent was applied in the removal of Cr (VI) obtaining a Qmax capacity determined by the Langmuir model of 55.8 mg/g.