6.9.95

How chemistry sees us through 
everyday life 

Researched by The Royal Society of Chemistry

ASPIRIN: one of the oldest pain remedies, isolated from willow bark, still offers new 
treatments. Half a tablet a day can reduce the risk of heart disease and stroke; can also treat 
arthritis. Understanding body chemistry helps to target drugs and minimise side effects: 
the hunt for an alternative to aspirin produced ibuprofen.

DENTISTS: chewing gum containing sweetener aspartame can limit tooth decay from 
sweets. Patients are injected with pain-killing lidocaine; teeth filled with latest white filling — polymers containing silica powders. Low-abrasive toothpastes with calcium carbonate and 
fluoride help prevent decay.

SAFE SUN: sunblocks with titanium dioxide and zinc oxide protect skin from both UVA 
and UVB rays. Two-in-one shampoos use as conditioners new silicone polymers that will 
mix with detergents, unlike traditional conditioners. Chanel No 5 was the first successful 
perfume to include a synthetic fragrance.

PHOTO-ME: launched by George Eastman in 1888, the first mass produced Kodak camera 
used light sensitive silver halides to produce a black-and-white negative. Modern films use a 
plastic support for the silver halides, suspended in gelatin, and incorporate layers of dyes 
enabling colour shots to be taken.

FIBRES: synthetic fabrics lycra and tactel show up on centre court, matched by hard-wearing 
shoes with kevlar toes. Tennis racquets made of ultra-strong composite materials such as 
epoxy resin reinforced with carbon fibres give players extra power. Carbon fibres are so 
strong they are also used in the brakes of Concorde.

DIG DEEP: plants need 22 different chemical elements from the soil: absence of just one can 
stunt growth. Modern fertilisers supply a balance of essential nutrients, primarily nitrogen, 
phosphorus and potassium. Chemists can also control plant growth through hormone treatment, producing grass that needs less mowing.

SOAP SUDS: biological detergents are milder than soap and work in lukewarm water, saving 
energy. Developed in the Sixties, they contain enzymes like trypsin that "eat" stains such as 
grass and sweat, which stick strongly to textile fibres. "Molecular sieves" soften the water 
and stabilise the foam.

TOMORROW'S TOMATOES: chemists can double the shelf-life of tomatoes using gene 
modification to produce better fruit. Apples and potatoes can be prevented from bruising by 
reducing the level of the enzyme responsible. Vegetarian cheese is made with synthetic rennet to avoid using animal products.