Supporting Information for Manuscript DOI Prep.201500231

Supporting Information for Manuscript DOI prep.201500231

Spectral Investigation of Copper(I) halides CuX (X = F, Cl, Br, I) in Pyrotechnic Combustion Flames

Ernst-Christian Koch*[a]

1.  Experimental Section

Pyrotechnic compositions were prepared from the following ingredients: magnesium, SFM, atomized 325 mesh; sulphur, precipitated, > 99 %, Roth KG. Copper hydroxide carbonate, > 99 % Potassium chlorate, > 99 % Merck KG, Potassium bromate, ALFA AEASAR, > 99.5 %, Potassium iodate, > 99 %, Merck KG.

Sample formulations were prepared on a 1000 mg scale in an agate mortar. To homogenize formulations were dampened with dried acetone and mixed until a uniformly coloured paste was obtained. This was stored in a drying cabinet for 12 h and then consolidated with a hydraulic press in a brass die to pellets measuring 4 mm in diameter and about double height. The pellets were stored in an exsiccator over phosphorus pentoxide until use.

The samples were glued on Ceran® plates and ignited with the tip of a butane torch in a fume hood. The spectrometer used was a TRISTAN, with a 400 µm core fibre and 1013 diode array with a spectral resolution of 0.29 nm. Acquisition times varied between 15 ms – 100 ms depending on luminosity of the formulation. The spectrometer was wavelength calibrated with a neon tube and Hg pressure lamp. Intensity calibration was carried out with a tungsten filament lamp and adjustable power supply.

All samples prepared are energetic materials which are prone to accidental ignition by friction, impact, electrostatic discharge and thermal heating. Therefore the use of personal protective equipment is indicated.

2.  Peak List

The following peaks were identified to belong to the respective copper(I) halide.

Table 1. Composition # 1: CuF peaks identified

Experimental Peak (nm) / Intensity
478.8 / 0.08
494.3 / 1
507.2 / 0.2
570 / 0.24

Table 2. Composition #2: CuCl peaks identified

Peak (nm) / Intensity / Peak (nm) / Intensity
409.8 / 0.06 / 478.5 / 0.08
415.4 / 0.13 / 481.8 / 0.14
424.6 / 0.33 / 486.8 / 0.19
430.9 / 0.69 / 490.4 / 0.35
437.7 / 0.94 / 497.2 / 0.25
446.3 / 1.00 / 501.1 / 0.36
451.7 / 0.41 / 508.0 / 0.20
455.0 / 0.53 / 511.8 / 0.25
459.7 / 0.23 / 517.8 / 0.14
463.9 / 0.11 / 524.9 / 0.14
468.4 / 0.07 / 540.1 / 0.16
473.7 / 0.04 / 551.5 / 0.07

Table 3. Composition # 3: CuBr peaks identified

Peak (nm) / Intensity / Peak (nm) / Intensity
408.8 / 0.1 / 465 / 0.14
413.0 / 0.21 / 476.9 / 0.09
417.4 / 0.31 / 482.5 / 0.13
422.4 / 0.51 / 489.4 / 0.16
427.5 / 0.62 / 497.1 / 0.24
430.5 / 0.78 / 505.5 / 0.19
435.2 / 0.95 / 511.1 / 0.05
441.4 / 1.00 / 513.5 / 0.09
448.29 / 0.77 / 524.2 / 0.06
454.9 / 0.40

Table 4. Composition #4 CuI peaks identified

Peak (nm) / Intensity / Peak (nm) / Intensity
406.5 / 0.21 / 478.2 / 0.58
423.7 / 0.43 / 485.9 / 0.59
430.0 / 0.49 / 494.9 / 0.74
433.8 / 0.56 / 499.6 / 0.77
438.6 / 0.62 / 504.4 / 0.88
443.0 / 0.63 / 509.2 / 0.85
449.0 / 0.63 / 516.30 / 0.91
454.7 / 0.64 / 524.0 / 1.00
460.9 / 0.60 / 532.40 / 0.95
465.4 / 0.52 / 541.0 / 0.91
471.0 / 0.53 / 550.20 / 0.82

3. Chemical equilibrium calculations

The chemical equilibrium calculations were performed with EKVI Calc 4.30. The asterisk, *, behind some entries denotes species for which EKVI code uses thermodynamical properties that have been extrapolated.

Formulation # 1

Magnesium 45 wt.-%

Polytetrafluoroethylene 30 wt.-%

Viton 5 wt.-%

Copper 20 wt.-%

Equilibrium Temperature: 1922 °C

Gaseous products

Species / g / Pa
Mg / 27.13 / 81627.420
MgF2 / 7.645 / 8974.355
MgF / 2.716 / 4585.970
H2 / 0.08525 / 3092.439
Cu / 1.861 / 2142.011
HF / 0.1291 / 471.769
MgH / 0.08907 / 257.264
H / 0.001329 / 96.421
Mg2 / 0.02221 / 33.417
Mg2F4 / 0.03179 / 18.654
Cu2 / 0.0303 / 17.438
C2H2 / 0.00314 / 0.713*
CuF / 0.000502 / 0.445*

Condensed

Species g

C(graphite) 8.215

MgF2(l) 33.93

Cu(l) 18.11

Formulation # 2

Potassium chlorate 61 wt.-%

Malachite 19 wt.-%

Sulphur 20 wt.-%

Equilibrium Temperature: 1397 °C

Gaseous products

Species / g / Pa
SO2 / 35.88 / 43012.463
KCl / 22.81 / 23497.268
O2 / 4.299 / 10314.885
H2O / 1.665 / 7100.856
CuCl / 9.108 / 7066.406
CO2 / 3.384 / 5905.221
K2Cl2 / 5.23 / 2694.232
HCl / 0.3366 / 708.971
Cu3Cl3 / 1.449 / 374.700
SO3 / 0.2461 / 236.087
Cu2Cl2 / 0.4429 / 171.847*
K2SO4 / 0.2779 / 122.502
Cl / 0.01601 / 34.684
KOH / 0.02025 / 27.723
OH / 0.004459 / 20.133
Cu4Cl4 / 0.08385 / 16.263*
CuO / 0.01084 / 10.467

Condensed

Species g

Cu2O(l) 4.445

K2SO4(l) 10.29

Formulation # 3

Potassium bromate 68 wt.-%

Malachite 15 wt.-%

Sulphur 17 wt.-%

Equlibrium Temperature: 1726 °C

Gaseous products

Specie / g / Pa
SO2 / 29.18 / 47643.015
KBr / 26.7 / 23466.870
H2O / 1.121 / 6507.092
CO2 / 2.656 / 6313.561
Cu3Br3 / 18 / 6209.196
O2 / 1.559 / 5096.648
KOH / 1.571 / 2929.306
K2SO4 / 2.999 / 1799.532
K / 0.116 / 310.358
Cu / 0.1485 / 244.497
CuO / 0.1824 / 239.938
K2Br2 / 0.4811 / 211.465
OH / 0.01826 / 112.369
SO3 / 0.046 / 60.106
Br / 0.02872 / 37.602
CO / 0.009732 / 36.345
SO / 0.01421 / 30.924
CuBr / 0.03706 / 27.023
O / 0.002292 / 14.986
KO / 0.005934 / 11.267

Condensed

Species g

K2SO4(l) 9.871

Cu2O(l) 5.245

Formulation # 4

Potassium iodate 56.8 wt.-%

Malachite 27.4 wt.-%

Sulphur 15.8 wt.-%

Equilibrium Temperature: 1030 °C

Gaseous

Species / g / Pa
SO2 / 23.12 / 49426.335
Cu3I3 / 21.98 / 5268.900
KI / 6.813 / 5620.498
K2I2 / 5.215 / 2151.130
CO2 / 4.876 / 15168.353
Cu2I2 / 4.453 / 1600.935*
H2O / 2.521 / 19160.558
CuI / 1.639 / 1178.410
I / 1.292 / 1394.232
Cu4I4 / 0.653 / 117.436*
I2 / 0.1551 / 83.684
HI / 0.1111 / 118.955
CO / 0.002426 / 11.855

Condensed

Species g

K2SO4(beta) 14.21

Cu2S(s) 7.995

KI(l) 4.954