Egyptian Nobel prize winning chemist Zewail dies

Nobel prize-winning Egyptian-American chemist Ahmed Zewail, who served as a science and technology advisor to US President Barack Obama, died Tuesday in the United States. He was 70.

Zewail, a naturalised US citizen, won the Nobel prize for chemistry in 1999 for his groundbreaking work in the study of chemical reactions in extremely short timescales.

He was the third Egyptian to win a Nobel prize and the country's first scientist to do so.

His work showed that it is possible with rapid laser technique to study in slow motion how atoms in a molecule move during a chemical reaction.

According to the Nobel Prize website, Zewail's work led to the birth of the research area called femtochemistry, "which enables us to understand why certain chemical reactions take place but not others".

His discoveries offered scientists greater insight into chemical and pharmacological processes with implications across a range of disciplines including human health, electronics and high precision machinery.

"Egypt has today lost one of its faithful sons and a brilliant scholar" who devoted his life to scientific research, Egyptian President Abdel Fattah al-Sisi said in a statement.

Born in the northern Egyptian town of Damanhur in 1946, Zewail studied chemistry at Alexandria University before moving to the US in 1969 where he gained his doctorate from the University of Pennsylvania in 1974.

He taught physics and chemistry at the Californian Institute of Technology (Caltech), where he went on to oversee the university's Laboratory for Molecular Sciences.

Caltech president Thomas Rosenbaum described Zewail as a "quintessential scholar and global citizen".

"(His) fervour for discovery never abated and he serves as an inspiration to colleagues and generations of students," Rosenbaum said late Tuesday.

In 2009 Zewail was appointed to Obama's Council of Advisors on Science and Technology, and later that year he was named the first US science envoy to the Middle East.

Until his death Zewail worked at the California Institute of Technology.

He was a member of several prestigious scientific institutions including the National Academy of Sciences and the US American Academy of Art and Sciences. He was a fellow of London's Royal Society.

Zewail was married with four children.

His body will be repatriated to Egypt.