Polyaniline (PANI): an innovative support for sampling and removal of VOCs in air matrices

Photocatalytic and Oxidative Synthetic Pathways for Highly Efficient PANI-TiO2 Nanocomposites as Organic and Inorganic Pollutant Sorbents

“…The reference composite (1 × 1) presented sharp and well resolved peaks of the ES-I form of the emeraldine salt [35], characteristic of a high crystallinity degree. The presence of well defined peaks due to crystalline PANI phases, which are far less resolved in both PANI_ref [14] and in PANI from oxidative aniline polymerization [35], is indicative of a more ordered arrangement of the polymer chains in the composite samples with respect to pure PANI. It should be noted that our composites are far more crystalline than PANI composites prepared via traditional oxidative polymerization in the presence of TiO 2 or even other oxides [28,[36][37][38][39][40].…”

“…Stoichiometric molar ratios of photocatalyst and H 2 O 2 with respect to aniline dimer (columns 2 and 3), weight percentage of PANI and TiO 2 in the final products obtained from TG analyses (columns 4 and 5), measured specific surface area of each composite and calculated surface area of a physical mixture with same composition (columns 6 and 7). For the sake of comparison, PANI-TiO 2 composites were compared with a pure PANI sample (named PANI_ref) prepared according to the green synthetic approach previously proposed by some of us, using aniline dimer, H 2 O 2 (H 2 O 2 : dimer molar ratio = 5) and FeCl 3 catalyst [14].…”

“…On the contrary, the 1 × 3 sample ( Figure 4D) is characterized by larger and smooth aggregates, whereas the 3 × 3 sample displays intermediate morphological characteristics (Figure 4B). It should be noted that the reference sample (PANI_ref) presents an even more compact morphology characterized by micrometric and smooth particles [14].…”

“…For all these reasons, PANI-based materials and composites are now a hot-topic in the materials science community and have been applied in numerous fields, ranging from photovoltaics, anticorrosion and biomedical devices to sensors, electrochemistry and electronics [1][2][3][4][5][6][7][8][9][10][11]. Furthermore, in recent years PANI has drawn increasing attention as alternative sorbent for pollutant remediation from both water and air due to its high sorption capability and ease of regeneration [12][13][14][15][16]. In this regard, polyaniline represents a promising alternative to currently adopted materials, such as activated carbon, thanks to the fact that PANI does not require energy-consuming thermal activation and regeneration treatments.…”

“…Besides their significant side effects on the properties of the final product, the discarded electrolyte solution is highly pollutant. As an alternative, an environmentally friendly process was developed by some of us [14] adopting more benign compounds, such as aniline dimer (N-(4-aminophenyl)aniline) as starting reagent, H 2 O 2 as oxidant and FeCl 3 as catalyst. Even though aniline dimer is produced by chemical routes and labeled as toxic and irritant, it is not carcinogenic, differently from aniline monomer, and its solid form makes handling easier and safer.…”