Dataset for "Zeolites fit for a Crown: Probing Host-Guest Interactions with Thermogravimetric Methods"

Data collection method:

The powder X-ray diffraction (PXRD) data were collected using a Bruker D8 Advance X-ray powder diffractometer in the University of Bath CCAF. This instrument used Cu Ka radiation of a 1.5418 A wavelength. The thermogravimetric (TG) and differential thermal analysis (DTA) were collected using a Setaram Setsys Evolution TGA 16/18 instrument at the University of Bath CCAF. This was equipped with a Pfeiffer Vacuum Omnistar GSD 320, with a quadrupole mass analyser and a SEM detector for mass spectrometry (MS) of the evolved gases. TG and DTA analysis were performed by heating the sample in an air atmosphere (flow rate 20 mlmin-1) from 30C to 600C using a ramp rate of 5 Kmin-1. Ramp rates of 2 and 10 Kmin-1 were also used. For zeolite samples Na-X and EMC-2 intermediate static heating stages were used, being 60 minutes at 130C for the former and 20 minutes at 180C for the later. MS was performed by scanning the m/z ion range from 0-200. This was followed by specifically tracking the m/z ions of 18, 32 and 44, which correspond to water, oxygen and carbon dioxide respectively.

Data processing and preparation activities:

Data was processed using Microsoft Excel and Origin Pro 9.0. For DTA analysis, the background was removed manually using a polynomial function. The signals were then scaled accordingly by the total mass% of organic 18C6 material present in the samples. The determination of the activation energy is detailed in the "Additional Information".

Additional information:

The activation energy was calculated following the European Standard ISO 11358-3:2014. The onset of decomposition was determined as the midpoint between the peaks in the derivative TG curves (dTG) for water desorption and decomposition. The offset of decomposition was accepted as the final measurement in the TG data at 600C. The mass% values within this range were converted into parameter "Alpha", whereby the value is '0.0' at the onset decomposition, and '1.0' at the offset. This was performed for the three ramp rates: 2, 5 and 10 Kmin-1. At '0.1' intervals of Alpha, the logarithm of the ramp rate used was plotted against the inverse of the temperature. This produces a straight for each Alpha value, of which the gradient corresponds to the activation energy. For zeolites RHO and ZK-5, the activation energies were calculated using Alpha values of 0.1, 0.2 and 0.3, followed by taking an average. For zeolite Na-X two events were detected, and the Alpha values used were 0.1, 0.15 and 0.2 for the first event, and 0.8, 0.85 and 0.9 for the second event, with averages taken. For zeolite EMC-2 two events were also observed, with Alpha values of 0.1, 0.15 and 0.2 taken for the first event, and 0.7, 0.75 and 0.8 taken for the second event, with averages taken.