## 2 Materials and Methods
### Chemicals
#### 2.1.3 Material Characterization  
The decomposition temperatures of the ANFO samples produced were determined using an Automatic Explosion Temperature 402 Tester (OZM Research, Bliznovice, Czech Republic). The measurement of the decomposition temperature was conducted five times (one \"shot\" consisting of five separate samples) for each sample, and the final result is presented as an average. Samples of 50 \(\pm\) 1 mg were used to determine the ignition/explosion temperatures. The measurement was carried out in the range of 100-400 \({}^{\circ}\)C. Heating rates of 5 K/min, 10 K/min, 15 K/min and 20 K/min were used to determine the pseudo-activation energy using the Kissinger and Ozawa methods [15; 16].  
Raman spectra were obtained using the inVia (Renishaw, Wotton-under-Edge, UK) confocal Raman microscope with a diode laser at an excitation line of 532 nm, equipped with a long-focus 20\(\times\) objective (Olympus Plan N NA = 0.25). The spectra were recorded at a light power of 500 mW and with a spectral resolution of approximately 1 cm\({}^{-1}\) (2400 lines/mm grating) in the spectral range of 1100-3200 cm\({}^{-1}\) using an EMCCD Newton 970 camera (Andor, Belfast, UK) as the detector. The acquisition time for a single spectrum was 3 s with 5 acquisitions. All spectra were pre-processed by removing cosmic radiation and baseline correction using the WiRE 5.2 software from Renishaw, UK. Samples containing fuel oil (diesel), i.e., ANFO-type EMs, were not investigated. This is both due to safety concerns (ANFO is capable of undergoing detonation) and due to the fact that Raman spectroscopy is a surface investigation method (fuel oil signals would obscure the signals arising from the NC-coated AN particles).  
IR spectroscopy measurements were performed on a PerkinElmer Spectrum Two spectrometer (Waltham, MA, USA) equipped with a universal attenuated total reflectance (UATR) module (diamond). Spectra were recorded in the range of 450 to 4000 cm\({}^{-1}\). Samples containing fuel oil (diesel), i.e., ANFO-type EMs, were not investigated. This is both due to safety concerns (ANFO is capable of undergoing detonation) and due to the fact that IR ATR spectroscopy is a surface investigation method (fuel oil signals would obscure the signals arising from the NC-coated AN particles).  
The morphology of the components, additive-supplemented gAN, and the respective ANFO was investigated using a Phenom ProX (Phenom-World BV, Eindhoven, The Netherlands) scanning electron microscope (SEM). Regarding the SEM operation parameters, the working distance was 10 mm, the acceleration voltage of the incident electron was 10 kV and the current intensity of the incident electronic beam was about 95 mA. Samples containing fuel oil (diesel), i.e., ANFO-type EMs, were not investigated as the high vacuum present in the SEM sample chamber would result in the evaporation of the fuel oil, which would damage the instrument.  
Scanning electron microscopy with energy dispersive X-ray spectroscopy system (SEM-EDS) experiments were carried out using an Inspect 550, FEI (Hillsboro, OR, USA) instrument, equipped with an EDS Octane Elect Plus, EDAX (Mahwah, NJ, USA) detector. Prior to measurement, the samples were coated with an 8-micrometer-thick gold layer to ensure conductivity and to safeguard the instrument, as the materials exhibited poor adhesion to the SEM stage. For this reason, gold was taken into account in the mathematical model, since its spectral line is close to that of sulphur, potentially leading to a false positive result in the EDS analysis. SEM images (used for overlaying EDS data) were obtained using an ETD detector, whereas elemental composition mapping was carried out using an EDS detector. The measurements were conducted at 15 kV.  
Friction and impact sensitivity were performed according to relevant international standards and using the Peters friction apparatus [17] and BAM Fallhammer apparatus [18], respectively.