Atlas evacuable pellet die

50 mg of the powdery a-[Au(SR)]_n solids were deposited between two 13 mm highly polished stainless steel disks and inserted in a Specac™ Atlas™ Evacuable Pellet Die, usually used for KBr pellet production for FTIR analysis samples. The pressure applied with the pressing system was 10 tons for 60 s at room temperature and under ambient atmosphere. Pellets with 100 mg of powder were also prepared under the same conditions. All the characterizations of the glasses, except for transmittance, were carried out on the ones fabricated with 50 mg of amorphous powder.

A pharmaceutical tablet formulation (model sample material) was prepared as described by Nirwan et al., 2019 [3 (link)]. Briefly, a powder mixture of HPMC (30% w/w) and propranolol (70% w/w) was prepared using a tubular mixer (Artisan Technology Group^®, Kansas City, MO, USA) at 50 rpm for 15 min, followed by content uniformity testing of the mixture using ultraviolet spectroscopy which confirmed uniform mixing. Tablets of 300 mg of the powder mixture were prepared using a Testometric™ M500–50 CT (Testometric™ Company Ltd., Rochdale, U.K.) apparatus directly connected to a computer with a 50 kN load cell equipped with a 13.00 mm Atlas Evacuable Pellet Die (Specac^® Limited, Orpington, U.K.). Polished flat-faced punches were used, where the lower punch was held stationary while the upper punch moved at a speed of 3 mm min⁻¹ during loading and 1 mm min⁻¹ on unloading and an applied pressure of 150 MPa was used. Following ejection of the tablets, they were stored in an air-tight container over silica gel for 24 h to allow for elastic recovery before further investigation. All compaction work was conducted at a relative humidity and temperature in the range of 20% to 35% RH and 25 °C to 27 °C, respectively.