Frontier fourier transform infrared ftir spectrometer

The infrared properties of the composite materials were characterized according to standard protocols.^25,26,42 (link) The total infrared reflectance and transmittance spectra were obtained by using a Frontier Fourier transform infrared (FTIR) spectrometer (PerkinElmer) outfitted with a mid-infrared integrating sphere (Pike Technologies) and were analyzed with the Spectrum (PerkinElmer) and Origin 8.5 (OriginLab) software packages. The measurements were referenced to a National Institute of Standards and Technology (NIST)-verified Pike Technologies Diffuse Gold Standard. The composite materials were mounted on home-built size-adjustable stages, which allowed for the application of strains between 0% and 100%. The total reflectance spectra were collected at an illumination angle of 12°, and the total transmittance spectra were collected at a normal illumination angle. The spectra were collected in an indoor environment at room temperature, i.e., typically ∼20 °C. The average reflectance and transmittance value changes were calculated for the composites over the wavelength range of 4.5–16.5 μm by subtracting the average values at strains of 0% from the average values at strains of >0%. The experiments were performed on at least eight different composite materials of each type, with similar results obtained in each instance.

An Electrothermal 9100 apparatus (Electrothermal Engineering Ltd., Southend-on-Sea, UK) was used for melting point acquisition. IR spectra were measured on a Frontier Fourier transform infrared (FT-IR) spectrometer (PerkinElmer, Waltham, MA, USA) with an ATR accessory. NMR spectra were recorded on an Avance DPX 400 spectrometer (Bruker, Billerica, MA, USA) running at 400.13 MHz for ¹H and 100.61 MHz for ¹³C. EI-MS were obtained on a MAT 95 spectrometer (70 eV, Finnigan, San Jose, CA, USA). Thin layer chromatography (TLC) was realized on precoated silica gel glass plates (5 × 10 cm, Merck silica gel 60 F₂₅₄, Darmstadt, Germany). Column chromatography was carried out on silica gel (60–200 mesh) purchased from J. T. Baker (Phillipsburg, NJ, USA). Size-exclusion chromatography was performed on Sephadex LH-20 (Lipophilic Sephadex, Amersham Biosciences Ltd., purchased from Sigma-Aldrich Chemie, Steinheim, Germany).

ATR-IR spectra were acquired using a Frontier Fourier transform infrared (FTIR) spectrometer (Perkin Elmer, Villebon-sur-Yvette, France) equipped with a Quest single reflection diamond attenuated total reflectance (ATR) accessory (Specac, Orpington, UK). The spectral range was set between 4000 and 400 cm⁻¹ with spectral resolution of 4 cm⁻¹. A drop ≈100 µL was deposited directly onto the diamond surface and spectroscopic measurements were performed immediately. Prior to sample measurement, a background spectrum was recorded in the air (4 averaged scans) and the sample spectrum (4 averaged scans) was automatically ratioed with it via software (Spectrum, Perkin Elmer), effectively normalising it to a maximum reflectance of 1 (100%). The data were further processed by software to express the spectrum in terms of sample absorbance. For each sample, 3 deposits have been measured and 3 spectra per drop have been collected. Ultimately, 9 spectra were recorded from each sample, capturing inter- and intra-variability during measurements. Spectra from pure compounds have also been collected using similar parameters. The entire operation to analyse 1 drop, including cleaning the ATR crystal, collection of the background, and collecting the IR spectrum from the sample, takes less than 30 s.