Highly sensitive explosives could become safer and greener by exploiting newly characterised ionic polymer structures, say chemists in the US. Such materials could replace explosives based on toxic heavy metals like lead and mercury salts.Sensitive materials are routinely used as primary explosives in detonators to set off larger amounts of less sensitive high explosives in mining or military applications. The challenge is to make them stable enough to be handled safely in the field, but also sensitive enough to detonate reliably, packing as much energetic punch as possible. 'It's a very fine balance,' says Louisa Hope-Weeks of Texas Tech University...