In this work temperature effect on poly(ortho-anisidine), POAN, and polyaniline, PANI, nucleation and growth (NGM) mechanism was studied. Synthesis conditions using potentiodynamic method (cyclic voltammetry) at all operating temperatures were first optimized; it was found that as the system cools, the monomer oxidation potential increases. The i-t transient obtained using the potentiostatic method (potential step) was complex and its deconvolution revealed it consists of three contributions for both investigated monomers. Experimentally obtained transient deconvolution for PANI and POAN showed that initially the deposit is formed from a progressive nucleation, with bi-dimensional growth (PN2D), followed by two three-dimensional growth contributions, one controlled by diffusion (PN3Ddif) and the other by charge transfer (PN3Dct). Nuclei are the main difference between these monomers NGM since in the case of POAN the nucleation is instantaneous (IN3Dct), whereas for PANI is progressive (PN3Dct). Hence, i-t deconvolution transients recorded during ANI and OAN electro-polymerization are virtually satisfied by the same equations. It was thus concluded that both monomeric units grow through a very similar mechanism, differing mainly by the required potential and the time (rate) it takes for each contribution to appear and, with that, each type of morphology. Temperature variation does not change the respective NGM, since the contributions are the same; just their proportions and definition time of each one varies. As expected, the diffusion controlled contribution was the most affected by temperature. In short, the obtained results validated the proposed electropolymerization model, based upon the solubility of the oligomers that precipitate to originate the polymeric deposit, and enables correlating and explaining polymer morphology changes as a function of the i-t transient recorded during its electro-synthesis.

Reliable analytical methods for quantifying the major phytocannabinoids cannabidiol (CBD) and Δ⁹-tetrahydrocannabinol (Δ⁹-THC) are essential to ensure quality control and regulatory compliance of cannabis-derived products. This study evaluated attenuated total reflectance Fourier-transform infrared spectroscopy (FTIR-ATR), combined with Partial Least Squares (PLS) and Classical Least Squares (CLS) chemometric models, to quantify cannabinoids in cannabis extract oils. FTIR-ATR spectra were collected over 4000–400 cm⁻¹ and processed using principal component analysis (PCA), Multiplicative Scatter Correction (MSC), and multivariate calibration. The PLS model, built on the optimal spectral regions of 1000–1800 cm⁻¹ and 3500 cm⁻¹ and validated by leave-one-out cross-validation, achieved strong predictive performance (RMSEC = 0.559%, RMSECV = 0.675%; R²cal = 0.910, R²cv = 0.869), indicating good predictive ability with no evidence of overfitting. Notably, the variables with the highest VIP scores were mainly associated with the extract-to-diluent ratio rather than CBD-specific absorbance bands. The CLS model, in turn, showed excellent agreement for pure cannabinoid standards (MSE on the order of 10⁻⁶; β coefficients between 0.98 and 0.99) but performed poorly in complex matrices, yielding negative coefficients for several samples. This limitation stems from unmodeled matrix components and the near-collinearity of the THC and CBD infrared spectra, which renders the CLS system ill-conditioned and causes noise to redistribute between the two basis vectors. Taken together, these findings indicate that the FTIR-ATR/PLS approach offers a robust, rapid, and cost-effective alternative for routine cannabinoid analysis. In contrast, the CLS model remains valuable for residual-based detection of unmodeled spectral contributions that may signal sample anomalies or contamination.

Polypyrrole (PPy) is one of the most extensively studied conducting polymers due to its favorable optical properties and electrical conductivity. In this work, the relationship between the morphology of nuclei formed during electrochemical synthesis and the electronic properties of PPy is investigated, with particular emphasis on controlling nu-cleation and growth mechanisms (NGM). Polymerization was carried out electrochemi-cally in acetonitrile containing pyrrole as the monomer and LiClO4 (0.1 M) as the sup-porting electrolyte. Potentiodynamic techniques, specifically cyclic voltammetry (CV), were used to establish the synthesis conditions, while potentiostatic techniques, such as chronoamperometry, were employed to analyze NGM and achieve morphological con-trol. The resulting polymeric films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV–Vis spectroscopy. The optical band gap was estimated using the Tauc method. Three distinct contributions to the NGM of PPy de-posited on indium tin oxide (ITO) conductive glass were identified: instantaneous nu-cleation with two-dimensional growth (IN2D), progressive three-dimensional nucleation controlled by charge transfer (PN3Dct), and progressive three-dimensional nucleation controlled by diffusion (PN3Ddif). When the growth mechanism was controlled, the electrosynthesized PPy exhibited band gap values of 3.31, 3.54, and 3.58 eV. SEM analysis revealed that IN2D leads to the formation of flat and homogeneous nuclei, whereas PN3Dct and PN3Ddif produce denser, more branched structures with growth perpen-dicular to the electrode surface. These findings demonstrate that precise control of NGM enables modulation of the electronic properties of PPy, providing opportunities to op-timize its performance in applications such as electrochemical sensors, supercapacitor electrodes, and organic electronic devices.

This work presents the use of an unmodified fluorine-doped tin oxide (FTO) electrode as an electrochemical sensor for the stable and highly reproducible detection of cannabidiol (CBD) in an oral pharmaceutical formulation (CBD-OS). This was achieved using an electrochemical methodology with 0.1 M LiClO₄ in acetonitrile as the electrolyte medium. The oxidation process of CBD on the FTO was extensively studied using cyclic voltammetry to analyze the influence of forced convection during the experiment. Quantification was performed by differential pulse voltammetry with standard addition to the dissolved CBD oral oil (CBD-OS), which allowed for the determination of a detection limit of 4.8 µM and a correlation coefficient R² = 0.9989. Statistical tests indicated no significant differences between the proposed electrochemical methodology and HPLC. The FTO electrode exhibited high reproducibility, withstanding more than 20 consecutive additions to the same electrode without loss of response, thanks to its intrinsic stability and the strategic use of forced convection. The use of an unmodified electrode enabled the development of a simple, reproducible, robust, and cost-effective analytical methodology for CBD analysis in pharmaceutical samples.