Mixed monolayer LB films of EHO and calix[8]arene

A Calixarene Promotes Disaggregation and Sensing Performance of Carboxyphenyl Porphyrin Films

“…This technique allows us to visualize directly the morphology of the films during their formation at the air/water interface. Therefore, changes in the molecular density, film thickness, or orientation inside the film are monitored in the film reflectivity. , Selected BAM images of the pure C8A monolayer are shown in the right column of Figure . It can be noticed that after spreading (and before any compression), two different regions can be observed: a large condensed domain, which corresponds to higher density areas (bright region) that coexist with a gas-phase region associated to the lowest-density areas of the monolayer (darker regions).…”

“…Research into porphyrins and derivatives deposited on Langmuir–Blodgett (LB) films for optical gas sensing continues attracting attention in defense and environmental applications. − The reason behind this interest relies on the modification of their electronic structure and, consequently, the UV–visible (UV–vis) spectrum in the presence of the analyte . This electronic structure emerges as a consequence of the conjugation of the electrons among the aromatic rings and can be tuned by precise modification of the peripheral positions or by changing the coordinating metal (if any) of the central hemo core.…”

“…Furthermore, it often makes LB films not uniform as a result of unsatisfactory reproducibility in Langmuir layer transfer from sample to sample . Among the possibilities established in the literature, there are several studies aiming at minimizing the aggregation of the porphyrin film by adding a calixarene matrix to form mixed films and enhance the porphyrin organization and uniformity of the LB films. ,,,,, Calixarenes are macrocycles made up of a varied number of bridged phenol units with a peculiar and useful supramolecular behavior . They often exhibit a good amphiphilic balance between the lower and upper rim and therefore form high quality monolayers at the air/water interface and stable and reproducible LB films .…”

“…1−12 The reason behind this interest relies on the modification of their electronic structure and, consequently, the UV−visible (UV−vis) spectrum in the presence of the analyte. 4 This electronic structure emerges as a consequence of the conjugation of the electrons among the aromatic rings and can be tuned by precise modification of the peripheral positions or by changing the coordinating metal (if any) of the central hemo core. Hence, when the gas molecules interact with a specific porphyrin, there is usually a charge transfer between the macrocycle of the porphyrin and the gas molecule that provokes a selective and monitorable change in the UV− vis spectra.…”

Pyroelectric and Conduction Properties of Z-type Calix[4] Acid Langmuir-Blodgett Films

“…Before the fabrication of a device, structural, electrical, optical and chemical properties of the device material must be known. In recent years, calix[n]arenes and their derivatives have been studied for their sensing applications such as gas sensing, [4][5][6] chemical sensing 7 8 and pyroelectric heat sensing. 9 For the investigation of pyroelectric activity in calix[n]arene molecules, alternate layer calix [8]arenas acid/amine LB films 10 11 were studied because of their extreme thermal stability (the melting point of calixarenes is typically around 250 C, compared with 50-70 C for many other organic materials).…”