Universal atr accessory

All of the ATR-FTIR measurements were performed using a PerkinElmer Frontier spectrometer equipped with the PerkinElmer Universal ATR Accessory. FTIR spectra were collected in the 600 to 4000 cm⁻¹ spectral region, with sensitivity of 4 cm⁻¹ over 64 scans. A software, PeakFit, was used for curve fitting. Another software Origin was used for application of Gaussian functions. The integral areas of curves were obtained by means of peak resolving [12 (link)].

In compliance with ASTM E1252 guidelines [26 ], FTIR spectroscopic analysis was employed to characterize the chemical constituents of the polyurea microcapsules (PUA-MCs). Utilizing a Frontier PerkinElmer spectrometer outfitted with a Universal ATR accessory, we performed a comprehensive analysis within the mid-infrared (mid-IR) spectral range. This robust analytical approach enabled the precise identification of functional groups integral to the chemical structure of both the tung oil and the polyurea matrix. The spectral scanning was conducted over a range of 4000 cm⁻¹ to 400 cm⁻¹ with a resolution of 4 cm⁻¹. Each spectrum represents an accumulation of 32 scans to ensure optimal signal-to-noise ratio and data fidelity.

Attenuated total reflectance (ATR)–FTIR
spectra were recorded on a PerkinElmer spectrometer, equipped with
a universal ATR accessory, with a diamond window in the range 4000–650
cm^–1.