Abstract
Photo of Kenneth SW Sing; courtesy of Jean Rouquerol.
Professor Kenneth Stafford William Sing, known among his friends and students as Ken Sing, died on 3 October 2016, at the age of 91, after a brief disease. This was after an unusually long scientific career of 67 years in the field of gas adsorption on powders and porous materials. Since, during all this time, his main objective was to favour international collaboration and friendship between all scientists in this field, many of us are greatly missing him today.
It is in the Exeter area that he was born on 25 February 1925, that he made his studies and was enrolled in 1945 by Dr John Gregg to be his first PhD student. It is in this same area that he came back, after losing his wife Ruby with whom he had had four children, Deborah, Ann, Claire and Jonathan and with whom he had shared 55 years. In 2007, he married Pat and, in great part thanks to her, could recover the vivid social life which was so important for him.
Ken Sing worked with ICI during one year, just after his PhD, which gave him the deep feeling that industry and academy were complementary to each other, which he never forgot. After seven years with a lectureship position at the Royal Technical College in Salford and nine years as the Head of the Department of Chemistry at the Liverpool College of Technology, he joined the new Brunel University, as Professor of Chemistry, in 1965. The adsorption laboratory he established there was quickly recognized as a leading laboratory in the field. This was all at once because of the original ideas developed there, because of the careful student selection and because of the broad opening of this laboratory to foreign visitors.
Incidentally, an early post-doc in Ken Sing’s laboratory was Danica Turk, Stephen Brunauer’s daughter-in-law. He kept links with many of his former students or young researchers and co-workers, who made their career either in the university or in industry, either in the UK (MR Harris, GC Bye, PA Cutting, R Mather, P Branton, J Freeman, G Gimblett, RA Roberts, M Day, M Kenny, RT Williams) or abroad in the US (D Carruthers, F Baker), Spain (M Alario-Franco, M Yates), Egypt (J Ragai), Portugal (P Carrott, M Ribeiro), Cyprus (C Theocharis), France (P Llewellyn), Australia (N Furlong, D Atkinson), India, Pakistan (A Rahman). We apologize for not mentioning all of them.
From the start, Ken Sing was especially interested in characterizing the microporosity of adsorbing materials. This was already a major topic for great scientists like MM Dubinin in the Soviet Union and JH de Boer in the Netherlands. Ken Sing favoured a simple, experimental way, ‘an empirical method for analysis of adsorption isotherms’ as he entitled it, well known and broadly used today as the alpha-s method. The difference with de Boer’s ‘t-method’ is that (i) it does not rely on any previous determination of the BET surface area and (ii) it takes into account the existence of specific interactions, especially between the nitrogen molecule and the surface of most oxide adsorbents. He studied this specificity by comparing the adsorbing behaviour of polar species like nitrogen or water with non-polar like argon. His links with industry and military research also led him to study and develop various activated carbons and more especially porous carbon cloth. He was also eager to determine and understand the adsorptive properties of novel adsorbents (new zeolitic materials, ordered mesoporous silicas, etc.).
His inclination for a collective scientific work made him much interested in selecting and characterizing the first reference adsorbents. This started with a round-robin involving more than 10 British laboratories which compared their adsorption results for nitrogen on a graphitized carbon black. Then, in the mid-70s, Ken Sing, together with Douglas Everett, managed to set up, in the scope of the Bureau Communautaire de Référence in Brussels, a group aimed at selecting and characterizing a number of reference materials for gas adsorption. It involved researchers like Mike Haynes and Ray Wilson from the UK, Cornelius Lippens from the Netherlands, Klaus Unger and Erich Robens from Germany, Nicola Pernicone from Italy and Jean Rouquerol from France. This was also the very start of European Community contracts supporting academic research teams.
A second way for him to help our community was to prepare collective recommendations. This was done in a perfect way in the scope of IUPAC where, as the chair of an ad-hoc sub-committee, he conducted the preparation of the recommendation for ‘Reporting physisorption data for gas/solid systems with special reference to the determination of surface area and porosity’, published in 1985. We dared to use the adjective ‘perfect’ because this recommendation was a real success and Ken Sing only learned two years ago that this document had been, by far, the most popular IUPAC document, i.e. most quoted in the scientific literature (over 4000 quotations!). Ken Sing was also asked to chair the IUPAC Commission of Colloids and Surface Chemistry, including Catalysis (1983–1985). He continued participating in successive IUPAC Committees and Sub-Committees and he worked actively with Matthias Thommes, Katsumi Kaneko, Alex Neimark, James Olivier, Francisco Rodriguez-Reinoso and Jean Rouquerol in the IUPAC Working Group which produced, in 2015, the last IUPAC recommendations on physisorption of gases.
A third way to help his colleagues was to favour meetings and common work. He was the mainspring for the organization of international meetings in collaboration with Fritz Stoeckli in Neuchatel (1978), Jean Rouquerol in Aix-en-Provence (1982), Klaus Unger in Bad-Soden (1987) and Francisco Rodriguez-Reinoso in Alicante (1990). Finally, these meetings gave rise to the well-established series of COPS Symposia, which take place every third year. The next one (COPS-XI) is to be organized in Avignon by his former student Philip Llewellyn and Ken will certainly be missed by all of us. Moreover, between 1990 and 2000, Ken Sing initiated several cooperative projects in the frame of the Training, Mobility and Research Program of the European Union between several European laboratories in the field of silica-rich zeolites of MFI-type and ordered mesoporous silica of type MCM 41.
A fourth way to be helpful was of course, for a Professor, to teach and to write textbooks. Ken Sing often gave courses on adsorption and adsorbents, like in the Porotec workshops organized every second year in Germany, which he co-chaired with Klaus Unger during nearly 30 years. His textbook co-authored with John Gregg, ‘Adsorption, Surface Area and Porosity’ (1967) was a great success. It was updated in 1982 and a new version co-authored with Françoise and Jean Rouquerol was published in 1999 (Adsorption by powders and porous solids: Principles, Methodology and Applications) and recasted in 2014, also co-authored by Philip Llewellyn and Guillaume Maurin. He also collaborated with Ferdi Schüth and Jens Weitkamp for the edition of the impressive five-volume ‘Handbook of Porous Solids’ published in 2002.
A fifth way to boost our field of science was to provide the researchers with specialized journals. This is why Ken Sing launched in 1984 the journal Adsorption Science and Technology for which he was the founding Editor. This was the first international journal essentially devoted to adsorption.
We can finally say that if, for Ken Sing, studying adsorption was a permanent source of challenge and pleasure, he still found more satisfaction in sharing his views and knowledge either with young students or with the many good and old friends he had all over the world. For many of us, he has been most inspiring and we are confident that our scientific community will be able to keep the friendly, fair and optimistic spirit which he so much contributed to develop.