Franks grew up in Berlin, the son of Henriette Muller and Paul Frankfurther , who ran the successful family textile business.
As the storm clouds gathered, Felix became aware of uncomfortable changes. His teacher appeared wearing a uniform and ordered the children to give the Heil Hitler salute and to ostracise their Jewish classmates.
When he and his sisters, Beate and Eva, were later expelled, he went to one of several Berlin schools hastily established for Jewish children and run by Felix’s aunt Vera Lachman, a distinguished classicist who had lost her own university job. After Kristallnacht all such schools were closed and the family made renewed efforts to find a place of safety. Eventually through Kindertransport the three children reached Southampton in April, 1939.
They attended Stoatley Rough in Surrey, a mixed boarding school founded by Dr Hilde Lion in 1934, to alleviate the plight of German refugee Jewish children from Nazi Europe. Recognised by the Ministry of Education in 1940, it continued as a school after the Second World War, its intake gradually changing to disadvantaged British children sent by local authorities. The school closed in 1960 when Dr Lion retired.
Two days before war broke out, his parents unexpectedly escaped from Berlin. The family lodged in two rented rooms in Hampstead (known affectionately by the Jewish refugees as Abrahampstead). His father borrowed money to send Felix to Haberdashers School.
In 1943, having changed his name to Franks, he enrolled into the army. Basic training was quite a shock and he recalled the remarkable combination of classes and backgrounds as the best way to assimilate into his new culture. He fought in the D Day landings and witnessed the liberation of Belsen. In 1945, waiting to be demobbed, Franks saw a note seeking fluent German speakers for “interesting duties.” As a result he was trained in espionage and spent two years working undercover in Soviet East Germany.
In 1948 Franks became naturalised and studied physical chemistry at London University on an ex-serviceman’s grant. His family experiences taught him that scientific training was the most transportable internationally. In 1950 he married fellow refugee Hedy Werner, originally from Brno, Czechoslovakia and a survivor of Terezin. They met through the Bnai Brith Youth Group (BBYO) and formed long-lasting relationships with other continental refugees.
Upon graduation, Franks worked both in industry and as a lecturer, gaining his PhD at Birkbeck. He held academic posts at Bradford University, Nottingham and Cambridge, interspersed with work for Unilever and a NASA fellowship in the US at Carnegie Melon.
His early research career focused on the fundamental physical properties of water, building up as complete a picture as possible of the properties of the water molecule.
His magnum opus on the physical chemistry of aqueous solutions brought him the nickname “Water Franks” in the scientific community. He edited numerous publications, assimilating as much knowledge as possible. This painstaking approach resulted in Polywater, the debâcle of a mythical molecule and a bandwagon that people were ready to jump on, without proper consideration of the evidence.
Later Franks turned to entrepreneurship, developing innovative preservation technologies. His first technology applied cloud physics to store solutions, unfrozen and uncontaminated down to -30 °C. His second, a foray into freeze drying, a little understood process at the time, but a key technique in the vaccines, pharmaceuticals and biotech industries, changed industrial thinking. He published a few low-key articles and ran a freeze-drying development and problem solving business. Within a few years his group of six people on the Cambridge Science Park had worked for 18 of the top 20 major pharmaceutical companies.
Franks’ third venture, working with a US west coast biotech company, was developing stable insulin that could be inhaled, meaning an end to daily injections for diabetic patients.
Franks was also an accomplished musician: a fine pianist and keen amateur cellist, playing in chamber music and orchestral ensembles into his late 80s. He sang in the Finchley Reform Synagogue choir and used to play the organ in Bradford Reform Synagogue.
Having seen his family scattered across the world, building a new, close family was crucial to Franks. He was happily married for 66 years and was a devoted father and grandfather. He frequently took the entire family on summer holidays, especially to the Dolomites of the South Tyrol, where he had spent many happy times as a child.
He is survived by his wife Hedy, daughters Suzanne and Carolyn and grandchildren, Emma, David, Hannah, Michael and Ben.
Born March 21, 1926
Died September 5, 2016