Abstract: Curable compounds, hydrogels, build materials, and methods of 3D printing are described herein. In some embodiments, a build material for 3D printing described herein comprises one or more compounds having the structure(s) of Formula (I) and/or Formula (II) herein. Such a build material may also comprise an additional acrylate component and water.

Abstract: A non-combustion, chemical heat source includes a heat chamber having a closed end and an open end. The heat chamber includes an apertured heat cartridge disposed at the open end of the chamber, an abutment disposed at the closed end of the chamber, an activating solution, a frangible seal separating the activating solution and the heat cartridge. The heat cartridge includes metallic agents that may come in a variety of configurations. The heat source is activated when the heat cartridge is pushed through and breaks the frangible seal allowing contact between the metallic agents and the activating solution. The heat cartridge includes an aperture in the bottom of the cartridge and absorbent paper surrounding the metallic agents, both of which control the transfer of the activating solution into the metallic agents to cause the chemical reaction. The heat sources may be incorporated into smoking articles and may also be used to heat foods or beverages, in hand warmers, and to heat equipment or materials.