Freeze monitoring device

A method for preparing an indicator for indicating an excursion below a threshold temperature comprising:

• mixing a diacetylene indicator with a solvent system wherein said solvent system comprises
• a host solvent and an activator solvent and wherein said activator solvent is miscible in said host solvent above said threshold temperature and separates from said host solvent below said threshold temperature;
• exposing said indicator to radiation to polymerize said indicator wherein said exposing is done at a temperature above said threshold temperature;
• wherein when said indicator is exposed to a temperature below said threshold temperature said activator solvent separates from said host solvent and reacts with said indicator and said indicator changes color.

A device for detecting excursions below a threshold temperature comprising:

• a compound of the formula R1—C≡C—C≡C—R2;
• wherein R1 and R2 are independently selected from (CH2)b—H, (CH2)bOH, (CH2)b—OCONH—R1, (CH2)b—O—CO—R1, (CH2)b—OCONHCH2COO—R1, (CH2)b—COOH, (CH2)b—COOM, (CH2)b—NH2, (CH2)b—CONHR1, (CH2)b—CO—O—R1, where b=1-10, and R1 is an aliphatic or aromatic radical and M is a cation, such as Na+ or (R1)3N+;
• a solvent system comprising a host solvent and an activator solvent wherein said activator solvent is miscible in said host solvent above said threshold temperature and separates from said host solvent below said threshold temperature;
• and
• wherein said compound is exposed to UV radiation above said threshold temperature to partially polymerize said compound and wherein when said device is exposed to temperature below said threshold temperature said activator solvent separates from said host solvent and dissolves unpolymerized compound thereby causing a color change in said partially polymerized compound.

A device for detecting excursions below a threshold temperature comprising:

• a compound of the formula R1—C═C—C═C—R2;
• wherein R1 and R2 are independently selected from (CH2)b—H, (CH2)bOH, (CH2)b—OCONH—R1, (CH2)b—O—CO—R1, (CH2)b—OCONHCH2COO—R1, (CH2)b—COOH, (CH2)b—COOM, (CH2)b—NH2, (CH2)b—CONHR1, (CH2)b—CO—O—R1, where b=1-10, and R1 is an aliphatic or aromatic radical and M is a cation, such as Na+ or (R1)3N+;
• a phase system comprising a host and an activator solvent wherein said activator solvent is miscible in said host above said threshold temperature and separates from said host below said threshold temperature;
• and
• wherein said device is prepared by the process of exposing said device to UV radiation above said threshold temperature to polymerize said compound and wherein when said device is exposed to temperature below said threshold temperature said activator solvent separates from said host and dissolves said polymerized compound thereby causing a color change.

A device for detecting a temperature excursion below a threshold temperature comprising:

• a diacetylene phase comprising polymerized diacetylene and monomeric diacetylene;
• a molten solvent phase comprising a host solvent and an activator solvent wherein said activator solvent is miscible with said host solvent above said threshold temperature and separates from said host solvent below said threshold temperature forming an activator phase;
• and
• wherein said activator phase dissolves said monomeric diacetylene from said diacetylene phase forming a monomer depleted polymer phase which is a different color from said diacetylene phase.

A device for detecting a temperature excursion below a threshold temperature comprising:

• a diacetylene phase comprising polymerized diacetylene and monomeric diacetylene;
• a gel phase comprising a gel and an activator solvent wherein said activator solvent is miscible with said gel above said threshold temperature and separates from said gel below said threshold temperature forming an activator phase;
• and
• wherein said activator phase dissolves said monomeric diacetylene from said diacetylene phase forming a monomer depleted polymer phase which is a different color from said diacetylene phase.

A gel formulation for detecting temperature excursions below a threshold temperature comprising:

• water;
• a solvent which is miscible with water above said threshold temperature and separates from water below said threshold temperature;
• a gelling agent;
• and
• a dispersion of partially polymerized diacetylene comprising polymerized diacetylene and monomeric diacetylene;
• wherein when said gel formulation is exposed to temperatures below said threshold temperature said solvent separates from said water and extracts said monomeric diacetylene from said dispersion and said dispersion changes color.