Fast Scanning Calorimetry of Organic Materials from Low Molecular Mass Materials to Polymers

Study of Glass Formation and Crystallization Kinetics in a 2D Metal Halide Perovskite Using Ultrafast Calorimetry

“…1,19 Due to a high propensity toward crystallization and facile reordering kinetics for the 1-MeHa 2 PbI 4 melt, crystallization cannot be averted when cooled at rates supported by conventional calorimeters (up to 50 °C/min). 1,19 On the other hand, ultrafast ("flash") calorimetry (heating/cooling rates >1000 °C/s) 21 has previously been used to study glass formation and cold crystallization phenomenon in metals, 22,23 organics, 24 polymers, 25 and chalcogenides. 26−29 Recently, we used flash-DSC to explore the kinetic control of solid−solid polymorphic structural transitions in an MHP.…”

“…The foremost requirement for a hybrid MHP to enable glass formation and reversible glass-crystal switching is for the hybrid to have a T m lower than its degradation temperature (typically, T d ≈ 200 °C), , which ensures a relatively stable working regime for the vitrification and devitrification processes. From within the limited set of two-dimensional (2D) MHP systems available to date with T m < 200 °C, we selected a representative member from this family with chemical formula [1-methyl-hexylammonium] 2 PbI 4 (abbreviated as 1-MeHa 2 PbI 4 ), which has one of the lowest reported T m values of ∼164 °C. ,, Melt processing of 1-MeHa 2 PbI 4 into films and monoliths generally leads to a crystalline phase, as demonstrated in our previous reports. , Due to a high propensity toward crystallization and facile reordering kinetics for the 1-MeHa 2 PbI 4 melt, crystallization cannot be averted when cooled at rates supported by conventional calorimeters (up to 50 °C/min). , On the other hand, ultrafast (“flash”) calorimetry (heating/cooling rates >1000 °C/s) has previously been used to study glass formation and cold crystallization phenomenon in metals, , organics, polymers, and chalcogenides. − Recently, we used flash-DSC to explore the kinetic control of solid–solid polymorphic structural transitions in an MHP …”

Mass Accommodation of Water on Ice at Environmentally Relevant Temperatures: Insights from Fast Scanning Calorimetry

“…Therefore, motivated by the significance of water–air chemical interactions and the scarcity of experimental results on the uptake of gaseous species by ice at temperatures directly relevant to the majority of Earth’s environments, we have conducted studies of ice sublimation kinetics at temperatures between −50 and −5 °C (223 and 268 K). Unlike previously employed experimental methods, , which often depend upon a combination of analytical techniques, we have exclusively used self-contained fast scanning calorimetry (FSC). , The well-established − general advantages of the FSC include extraordinary sensitivity, high data throughput, and broad temperature range of measurements before complete vaporization of samples. In addition to these, our quasi-adiabatic FSC apparatus also enables studies of free (uninhibited by vapor-phase diffusion) vaporization of aqueous films into vacuum at temperatures up to 0 °C. , …”