Methods for the fabrication of thin films with well controlled structure and properties are of great importance for the development of functional devices for a large range of applications. SILAR, the acronym for Successive Ionic Layer Adsorption and Reaction, is an evolution and combination of two other deposition methods, the Atomic Layer Deposition and Chemical Bath Deposition. Due to a relative simplicity and low cost, this method has gained increasing interest in the scientific community. There are, however, several aspects related to the influence of the many parameters involved, which deserve further deepening. In this review article, the basis of the method, its application to the fabrication of thin films, the importance of experimental parameters, and some recent advances in the application of oxide films are reviewed. At first the fundamental theoretical bases and experimental concepts of SILAR are discussed. Then, the fabrication of chalcogenides and metal oxides is reviewed, with special emphasis to metal oxides, trying to extract general information on the effect of experimental parameters on structural, morphological and functional properties. Finally, recent advances in the application of oxide films prepared by SILAR are described, focusing on supercapacitors, transparent electrodes, solar cells, and photoelectrochemical devices.

The fabrication of spiropyran-doped poly(vinylidene fluoride-co-hexafluoropropylene) electrospun fibers and the investigation of their optochemosensing properties when exposed to organic acid vapors are reported. The system is first activated through the conversion of the spiropyran molecules dispersed within the polymer to their fluorescent merocyanine photoisomers upon UV irradiation. The latter undergo protonation in the presence of acid vapors, giving rise to an evident colorimetric transition of the composite from purple to yellow and to a concurrent quenching in the spectral emission. Upon gas depletion under ambient conditions, the reversible interactions with the acid molecules lead to a spontaneous recovery of the free merocyanine form and, thus, of the initial materials' color and emission signal. Consistent with their higher surface to volume ratio, the nanofibrous mats exhibit a reduction in the response and recovery times by 25% and by more than 90% compared to composite fibers and films of the same material. The efficient vapor permeation/desorption confers a fast optical detection, which is linear with the acid concentration, and an outstanding reusability for over 40 protonation/recovery cycles. Therefore, the photoswitchable acidochromism of spiropyrans combined with the high specific surface area of the nanofibrous polymeric support provides a photoactivated fast optical and visual acid recognition suitable for integration within portable and reusable platforms targeting the real-time detection of acidic vapors for industrial and environmental applications.

We summarize the recent advances in optics and electronics of biopolymer-based nanocomposites. They are emerging as new materials for high-tech applications, thanks to the sustainability of the matrix and the functionalities of the nanofillers.

In this work, we report a structurally-colored multilayer film made of a silk-based material, inspired by the cuticle of Hoplia coerulea, a species of beetle able to change its color in the presence of moisture. For the generation of interference color, we combined the regenerated silk fibroin, which has a refractive index of 1.55, with a nanocomposite made of silk and titanate nanosheets, a novel 2D material which presents a high refractive index. The multilayer film was fabricated through a layer by layer deposition from the respective water-based solutions by spin coating. The final structure exhibits an interference peak in the transmittance spectrum centered at 400 nm, whose position responds to changes in the relative humidity of the environment. The stimuli-responsive properties of the film were characterized and a simple optical model for the sensing mechanism was proposed. Specifically, the silk-based multilayer showed a reversible color change when exposed to different relative humidities, and good performances in terms of reproducibility and stability over time.

Unmanned aerial vehicles (UAVs) are promising platforms for operations in alpine regions due to their compact size, advanced camera systems, and ability to take off and land in confined areas. In such conditions, one of the most significant challenges for UAVs is operating in icing environments, as ice accretion can compromise the aerodynamics of the propellers and can potentially lead fto a loss of control and vehicle failure. To date, active de‐icing solutions, such as electrothermal systems, have been employed in the aeronautical sector; however, these systems are energy‐intensive. This review addresses passive ice protection systems from a material science prospective, by focusing on coatings which mitigate ice formation without energy consumption. A comprehensive description of the strategies to design an icephobic surface is presented and the state‐of‐the‐art icephobic coatings are analyzed, such as superhydrophobic surfaces, elastomers, liquid infused surfaces, gels, polyelectrolytes, sol gel coatings, metal‐organic frameworks. A key focus is devoted to the characterizations for assessing ice mitigation of such coatings, i.e., contact angle and hysteresis measurements, and to the correlation between durability and number of icing and de‐icing cycles. The most relevant solutions for aerial vehicles are described in the final part of this review.