Inorganic phosphate ceramics and coatings

A metal phosphate ceramic precursor formulation comprising the following:

• at least one acidic phosphate component;
• at least one basic metal oxide or hydroxide component having a solubility constant (Ksp). of 10−4 or less in molar excess to that of the at least one acidic phosphate component;
• and
• at least one hydrophobic agent covalently combined with the at least one acid phosphate component and the at least one basic metal oxide or hydroxide component;
• wherein the at least one hydrophobic agent has one or more reactive groups capable of covalently bonding with the at least one acidic phosphate component;
• or the at least one basic metal oxide or hydroxide component;
• the hydrophobic agent is of the general formula (I) or (II) or (III) or (IV):
• where:
• R1, R2, R3, and R4 are, independently, hydrogen, C1-20 alkyl, phenyl, aryl;
• where alkyl includes straight-chain, branched, cyclic or acylic alkyl, or haloalkyl;
• Y1, Y2, and Y3 is, independently, hydroxyl, C1-4 alkoxy, phenoxide, or halogen;
• or, Y1, Y2, and Y3 is, independently, an alkali metal salt, an ammonium salt, an alkylammonium salt, a phenylammonium salt, or an alklyphenylammonium salt of Si—OH;
• b is 0-21;
• n is 1,000 to 1,000,000;
• m is 0-1,000;
• t is 1;
• and
• Z is sodium or potassium.

A method of forming a hydrophobic metal phosphate ceramic, the method comprising combining:

• (i) at least one acidic phosphate component;
• (ii) at least one basic oxide or hydroxide component having a solubility constant (Ksp). of 10−4 or less;
• and
• (iii) at least one hydrophobic agent comprising a Group IV element of silicon having at least one hydrocarbon covalently bonded thereto, the at least one hydrophobic agent directly covalently bonded or indirectly bonded to the at least one acidic phosphate component and the at least one basic metal oxide or hydroxide component.