Rutgers breakthrough in environmentally friendly chemicals

The chemicals, known as room temperature ionic liquids (RTILs), can perform many of the same functions as organic, petroleum-based solvents but will not burn or evaporate into the atmosphere.

Thus, RTILs won't contribute to air pollution and would likely cut the risk of workplace accidents, Chemists at Rutgers,​ The State University of New Jersey, reported in the American Chemical Society's Journal of Physical Chemistry B last week.

The findings come at a time when the health and environmental impact of the chemical industry is currently at the forefront of EU political debate, with an agreement on the REACH proposal expected in early 2006.

REACH will reverse the burden of proof from the authorities to the companies themselves, for the testing and risk assessment of chemicals that they either manufacture or import into the EU.

All companies within the industry are being encouraged and incentivised to phase out hazardous chemicals from their products and many large firms are already adopting a precautionary approach to end the use of chemicals of concern in their products.

A major barrier so far to the widespread adoption of RTILs has been that they are significantly thicker - or more viscous - than common organic solvents, such as acetone, alcohol or benzene.

The Rutgers scientists have invented a variant of these chemicals that could help them overcome this problem.

"RTIL viscosity compares to traditional solvents the way honey compares to water, impeding their flow, making lab procedures more difficult and manufacturing steps more energy intensive and costly,"​ researcher Edward Castner said.

"We have discovered that by substituting silicon for carbon at a key location in some RTIL molecules, we can cut the liquid's viscosity almost tenfold relative to the same ionic liquid without the silicon substitution,"​ he said.

RTILs can be used in industries such as chemical and pharmaceutical manufacturing, electroplating, pulp and paper production, and radioactive waste handling.

However, in spite of RTIL's safety and environmental advantages, higher costs could, slow their adoption.

Still, the Rutgers advance could make these chemicals suitable for some near-term specialty applications even though it may be too early to predict a widespread industrial market for RTILs.

"By pairing the molecules we've studied with molecules containing boron, we have a natural choice for handling radioactive wastes, such as plutonium, in spent reactor fuel rods,"​ Castner said.

"The boron would absorb neutrons generated by radioactive decay while the solvent would safely withstand the elevated temperatures that this decay causes,"​ he said.

Other likely applications include protein production and analysis, where specifically tailored RTILs could promote more complete reactions than water-based solvents and protect proteins from breaking down under analytic procedures.

The global chemicals industry is an important part of the world economy with an estimated US$1500 billion in sales in 1998, accounting for 7% of global income and 9% of international trade.

All economic indicators point to continued expansion of the industry over the next 20 years.

Over the entire life of a chemical product there is a potential for a negative impact on man and the environment and although these impacts can be complex and often unknown, some negative effects are well documented, such as chemicals found in the environment that are persistent, bioaccumulative and/or toxic (e.g. PCBs, dioxins).

Most recently, concern has been expressed about chemicals which interfere with the normal function of hormonal systems of humans and animals (i.e. endocrine disrupters), and substances which impact on children's health.

The industry is a major employer with over 10 million people employed worldwide, and 1.7 million jobs in the EU.

According to European Trade Union Confederation (ETUC), one out of every three occupational diseases recognised annually in the EU is from exposure to dangerous chemicals.