"Does your chewing gum lose its flavour on the bedpost overnight?"

　　The new Bristol University invention of Clean Gum should make this a thing of the past.

　　New kind of gum

　　The latest answer to this perplexing question from well-known singer, Lonnie Donegan, back in 1958, seems to be both yes and no, following a breakthrough by Bristol University scientists who have produced a new kind of chewing gum.

　　The new Clean Gum is covered with a film of water and often won't stick to any surface, even a bedpost. It does though, according to the researchers, have a great taste.

　　Professor Terence Cosgrove and his colleagues in the University's School of Chemistry have developed the new gum, currently called Rev-7.

　　Spin-off company, Revolymer

　　Working through his spin-off company, Revolymer, Cosgrove sent six people out to various places in North Wales and Bristol to chew different gums for 20 minutes - including the new invention. They were then stuck on paving stones to see whether they degraded.

　　The professor and his team found that commercial chewing gums without the special ingredient were still stuck on the paving stones eight days later. But he was very pleased to report that "ours was gone".

　　Film of water the key

　　The film of water around Rev-7 is the key. All the chewed gums were put into phials of water and it was found that after seven weeks the commercial gum was still there with algae growing on it. The new gum, on the other hand, had dispersed in the water as a fine, white powder. This means "it will degrade in the environment," said Professor Cosgrove.

　　The phial on the left contains the ordinary chewing gum with algae growing on it. The special Clean Gum in the other phial has dissolved in the water. (c) Bristol University

　　“The advantage of our Clean Gum", he said, "is that it has a great taste, it is easy to remove and has the potential to be environmentally degradable”. The research team report they have had the same success removing it from shoes, clothes and hair as they have from pavements.

　　Discarded gum less adhesive

　　“The basis of our technology", the Professor continued, "is to add an amphiphilic polymer to a modified chewing gum formulation which alters the interfacial properties of the discarded gum cuds, making them less adhesive to most common surfaces.”

　　Revolymer is planning to produce and launch the removable, degradable chewing gum next year.

　　Great help for local councils

　　The new invention could be of significant help to local councils in the UK - and elsewhere - who spend about ?150 million a year cleaning up discarded chewing gum.　  (Source: British Consulate-General in Chongqing)