What is the composition of black powder ?
Composed of the following three solid ingredients:
· Saltpeter: KNO3 niter (or, more rarely, NaNO3 Chilean nitrate).
· Sulphur: S.
· Carbon: C. Often as charcoal from wood (willow).
However, simply mixing the ingredients produces a decidedly inferior powder... To obtain what I consider proper black powder, the ingredients must be "incorporated" in a damp state. This allows the application of great pressure to form a dense cake, ultimately broken down into dry grains.
Simple earlier recipes calling for equal weights of the three components... Such mixtures would only burn violently without exploding... Also, explosion cannot occur if raw saltpeter is used.
In the 6 pages of the Book of Fires, there are 35 incendiary recipes, including the one for black powder
1 lb of native sulfur, 2 lb of linden or willow charcoal, 6 lb of saltpeter, which three things are very finely powdered on a marble slab.
Other recipes call for 40% more saltpeter than either sulphur or carbon (7:5:5 formula by weight). less sulphur and more charcoal (6:1:2). The most commonly quoted modern gunpowder composition seems to date from around 1800 and calls for 75% saltpeter (niter) oxidizer, with 10% sulfur (S) and 15% charcoal (C) fuel:
The stoichiometry of the following oversimplified reaction would correspond to about 74.8% niter, 11.9% sulphur and 13.3% carbon (roughly 101:16:18):
2 KNO3 + 3 C + S ® K2S + 3 CO2 + N2 + 572 kJ (505.8 cal/g)
The potassium sulphide solid residue forms a thick white smoke, capable of obscuring entire fields. Newer propellants leave little or no such residue when properly exploded. They are thus collectively known as smokeless powders. The simplest idea for a smokeless dark powder is called ammonpulver (AP) and involves ammonium nitrate (AN) with 10% to 20% charcoal, although the stoichiometry of the following reactions translates into only 7% to 13% carbon, by weight:
2 NH4NO3 + C ® CO2 + 4 H2O + 2 N2 + 629.6 kJ (874.4 cal/g)
NH4NO3 + C ® CO + 2 H2O + N2 + 228.6 kJ (593.5 cal/g)
Sulfurless powder (12.93% carbon) yields 772.6 cal/g, with 60% smoke:
4 KNO3 + 5 C ® 2 K2CO3 + 3 CO2 + 2 N2 + 1501.4 kJ
It takes 92.9 g of this mix to release a mole of gas, whereas only 67.6 g of black powder would suffice (sulfur prevents wasteful carbonate production).
Thermite brings about thermal destruction chemically.
Thermite is a mix of rust and powdered aluminum which can be ignited with a strip of magnesium to produce alumina and iron. This popular reaction is able to deliver molten iron at a very high temperature (about 2200°C).
Fe2O3 + 2 Al ® Al2O3 + 2 Fe + 851.5 kJ
The precise stoichiometry calls for 2.9 g of ferric oxide for 1 g of aluminum. An excess of aluminum helps prevent the formation of hercynite (FeAl2O4 ).
The usual recipe calls for 8 grams of iron oxide for 3 grams of aluminum.
Hot Ice (COMBAT USEFUL)
The crystallization of sodium acetate trihydrate is exothermic.
Na+ + CH3COO- + 3 H2O ® (NaCH3COO, 3H2O) + 38 kJ
The data from the above table is equivalent to a latent heat of 280 J/g.
This solidification occurs (below 58°C) only when nucleation can be initiated by various impurities or, more reliably, by a little bit of already crystallized sodium acetate trihydrate.
Interestingly, the reaction can also be triggered mechanically by a special clicker (consisting of a slotted metallic disk) that I found out quite by accident. That device made possible a product known as a heat pack or hand warmer. I’ve found this to be quite useful and very popular here among the glaciers.
The thing consists of a permanently sealed soft transparent pouch containing a clicker and some hot ice (possibly with a very slight excess of water). The pack is stored or carried in its liquid form. When needed, a mere click turns it into a very warm solid object (which can later be returned to it metastable liquid form by heating the pouch in boiling water until all traces of the crystals have disappeared).
What is the composition of traditional inks ?
Sepia is the most lasting of natural inks, but it's not lightfast. It is a dark brown liquid consisting of concentrated melanin, secreted by Mediterranean cuttlefish and other cephalopods (it's stored in ink sacs and ejected to confuse attackers).
As early as 2500 BC, writing inks were carbon inks consisting of fine grains of carbon black [from soot] suspended in a liquid. A red version of this ink can be made which uses cinnabar (HgS) instead of carbon. The idea is simple: When the liquid dries out, the solid pigment (C or HgS) remains which leaves a permanent trace. Such inks are best used on semi-absorbent stuff, like paper or papyrus (not parchment).
The problem is to keep the grains in suspension long enough to apply the ink. In plain water, fine grains of carbon black would aggregate and form flakes large enough to fall quickly to the bottom of the container. This flocculation process can be prevented with a hydrophilic additive which minimizes interactions between the grains by coating them. Early ink recipes may thus have called for various plant juices instead of plain water. It turns out that gum arabic acts this way to stabilize the ink into a colloidal suspension for days or weeks...
Instead, ink is produced as needed by grinding an inkstick on an inkstone after adding a little water (the inkstone also acts as an inkwell). ink-sticks consist of a pigment (usually soot from pine, oil or lacquer) and a soluble resin which holds the dry stick together and plays a critical part in the colloidal ink suspension produced by wet grinding.
Iron-gall ink normally includes a standard ink component, which provides both body (from gum arabic) and some initial coloring upon application of the ink. Otherwise, the main pigmentation of iron-gall ink comes paradoxically from water-soluble ferrous chemicals with little color of their own: When the ink dries in air, an oxidation occurs which turns these ferrous salts into insoluble ferric dark pigments. In addition, iron-gall ink may react with parchment collagen or paper cellulose, in a totally indelible way. Some poorly balanced iron-gall inks have even been observed to burn holes through paper.
It has been shown that an excess of ferrous salt in iron-gall ink leaves permanent traces of active soluble salts (not properly oxidized into inert pigments) which will catalyze the slow decomposition of cellulose, especially when acidity is present. This corrosion is reduced with a proper balance in the composition of the ink.
To prevent deterioration of historical iron-gall ink documents, I’ve found an interesting treatment: First, a saturated solution is applied which contains a calcium salt and its acid, namely:
· Calcium phytate: C6H6 (PO4Ca)6 (Phytic Acid Hexa Calcium Salt).
· Phytic acid: (CHOPOOHOH)6
The salt is soluble up to twice the molar concentration of the acid. This is an oxidation inhibitor which binds the metal ions. Then, acidity is neutralized with calcium bicarbonate, which creates an alkaline buffer and also leaves a phytate precipitate in the fibers, for continued oxidation protection.
Chemicals traditionally used as coloring agents in paints, dyes or inks.
Most of these substances are fairly harmless but some of them are too toxic for regular use, by modern standards at least...
At left is Blood ink, (the expensive dye behind the lake pigment used for red velvet) from bloodwood.
- Carbon Black : Lampblack, from soot. C (12.01 g/mol)
- Manganese Black : Manganese dioxide. MnO2 (86.937 g/mol)
- Cinnabar : Called vermillion, or Chinese red. HgS (232.66 g/mol)
- Red Ochre : Hematite. Ferric oxide. Fe2O3 (159.69 g/mol)
- Brazilin : Natural Red 24. C16H14O5 (286.2794 g/mol).
Turkey Red : Alizarin C14H8O4 (240.2109 g/mol).
- Sepia : Natural sepiomelanin from sepia officinalis
- Viridian : Chromium oxide dihydrate. Cr2O3 . 2 H2O
- Green Malachite : Basic cupric carbonate. CuCO3-Cu(OH)2
- Elven blue : Synthetic cuprorivaite. CaCuSi4O10
- Indigo : "Indian Blue". CAS 482-89-3 C16H10N2O2
- Blue : Palygorskite clay and indigo complex.
- Lapis Lazuli : Lazurite (sodium aluminum silicate) not "lazulite" (Na,Ca) 8 (AlSiO4 )6 (S, SO4 , Cl 2 ) especially: Na 8 (AlSiO4 )6 S.
- Nallic Blue : Ferric ferrocyanide. Ferric hexacyanoferrate. Fe4 [Fe (CN)6 ] 3 A chelating agent insoluble in water .