Gerhard Findenegg (1938–2019)

On 12 December 2019, our colleague and friend Professor Dr. Gerhard H. Findenegg (cf. Figure 1) passed away after just having completed the eighty-first year of his life. He leaves behind his wife Irmgard Findenegg-Gröll with whom he was married for fifty-four years, their three daughters Klara, Helene, and Eva with their spouses, and seven grandchildren. The Findenegg family lost a loving and caring husband, father, father-in-law, and grandfather who cannot be replaced. At the moment of writing this foreword our thoughts are once again with Gerhard's family.

Figure 1. Gerhard Findenegg (2017).

As his colleagues, we lost a great scientist, an inspiring academic teacher, a wise counsellor as well as a wonderful human being with whom it was always stimulating to interact regardless of whether this interaction was a professional one or in the more private realm. One could engage in deep conversations with Gerhard on almost any topic ranging from international politics over philosophical and social issues all the way to music.

Gerhard was born on 16 November 1938 in Klagenfurt (Austria) where he grew up. During 1944–1948 he attended elementary school in Klagenfurt and St. Georgen, also in Austria. He then moved on to grammar school, again in Klagenfurt, and finished his pre-university education with a baccalaureate degree (Abitur) in 1956 at the age of eighteen. In that same year, Gerhard began his undergraduate studies in Chemistry at the Technische Universität Wien. After graduating in 1960 he moved to the Universität Wien where he enrolled in graduate programmes in Chemistry and Physics. He completed his graduate studies in 1961 and was awarded his doctoral degree at the Universität Wien in 1965. The topic of his thesis was ‘Calorimetric Studies of Non-Electrolyte Solutions’. The Viennese years were an especially important period in Gerhard's life not only from a scientific perspective, but also from a private one because he became acquainted with Irmgard Gröll. The two were married in the same year that Gerhard received his doctoral degree.

After his years in Vienna another important period in Gerhard's life was about to begin in 1966 when the Findeneggs moved to Bristol (United Kingdom) where they stayed until 1968. Gerhard accepted an offer by Douglas H. Everett to become a postdoctoral fellow under his guidance. Everett initiated Gerhard's lifelong interest in adsorption and the wetting of surfaces and interfaces.

The time in Bristol was also a particularly happy period for the young family. Gerhard and Imgard Findenegg's eldest daughter Klara was born in 1967. Irmgard Findenegg has many happy memories of the time spent in Bristol to this day. Coming from a post-World War II Austria, she and Gerhard were completely fascinated by the democracy and the liberty they both experienced in the United Kingdom at the time.

In 1968, after returning from Bristol, Gerhard took up a position as a research assistant, again at the Universität Wien. There he completed his Habilitation in 1973 with a thesis entitled ‘Ordering phenomena at liquid-solid interfaces’, research that was clearly influenced and inspired by his time with Douglas H. Everett in Bristol. In the same year, Gerhard became a professor of Physical Chemistry at the Ruhr-Universität Bochum in Germany where he stayed until 1991; he served as Dean of the Faculty of Chemistry during the period 1989-1990.

In 1991 Gerhard left Bochum and accepted an offer from the Technische Universität Berlin (Germany) for one of the Chairs in Physical Chemistry which he held until his retirement in 2005. However, even after retirement, Gerhard remained scientifically active literally until he passed away: his last research paper appeared in print shortly after he was deceased.

Gerhard was an inspiring academic teacher who excelled in the clarity of his presentation and the precision of his writing on the blackboard. He quickly became famous and popular for the lucidity of his lectures among students attending his classes. This was already the case in Bochum and lasted in Berlin for many years after his retirement. Gerhard substituted his younger colleagues Michael Gradzielski and Regine v. Klitzing on numerous occasions if the two had other conflicting appointments. It is particularly noteworthy that Gerhard continued to ‘step into the breach’ so to speak until he reached his late seventies. To appreciate this, one needs to know that it takes about an hour by public transportation to get from Gerhard's former home located on the outskirts of Berlin to the university and that some classes in Physical Chemistry start as early as 8am during the winter months.

Gerhard was full of unconventional thoughts and ideas in conversations with others. He would always treat his conversation partners with politeness and with utmost respect. When on the rare occasion Gerhard regarded another person's response as slightly out of place he would reply ironically with a great sense of humour which usually made the other person reconsider his/ her point of view, laugh, or simply become quiet. In any event, anyone who ever had the privilege to experience these enlightening conversations with Gerhard will surely agree that one always learned something new from talking with him. Most of the time one would look at one's own initial opinions from a different perspective.

Gerhard also had a great knowledge and expertise in music. Among all the different periods of classical music, he was particularly fond of music from the eighteenth century. Nevertheless, he also enjoyed the music of composers of the so-called first and second Viennese Schools. Gustav Mahler ranked prominently among Gerhard's favourite musicians. Around the turn of the nineteenth century, Mahler was both a famous conductor and an equally well-known and influential composer. In the 1960s, when Gerhard was a young man, Mahler was very gradually rediscovered in post-World War II Austria and Germany after having been banned in both countries during the Nazi regime. In the 1960s students were again beginning to study the scores of Mahler's symphonies intensively, rediscovering him as a modern composer of the twentieth century. Gerhard was part of that rediscovery. He maintained a lifelong love for Mahler's overwhelming orchestral pieces.

When German and international friends and colleagues of Gerhard were informed of the very sad news of his death, we received a large number of very moving statements. During an interaction between George Jackson and Martin Schoen at that time, it was suggested by George that Gerhard be honoured with a memorial issue of Molecular Physics. Martin then quickly assembled a team of guest editors (Bob Evans, Jürgen P. Rabe, and Matthias Thommes) to handle the review process once papers had been submitted. This team was completed by George in his capacity as an in-house editor of Molecular Physics. We are also very pleased that Keith E. Gubbins offered to contribute his own personal memories of Gerhard to this foreword which was very much welcomed.

To assemble a team of two theorists and two experimentalists was a good decision because of Gerhard's own broad scientific interests. Gerhard is widely known and well-remembered by his peers in the scientific community for a multitude of scientific achievements including the thermodynamics of interfaces in soft matter, the physical chemistry of surfactant solutions, the adsorption in confined systems and nanomaterials, and the characterisation of materials with X-ray diffraction to name but a few salient areas [1–225]. As a consequence, we now bring together this memorial issue with high-quality contributions from various areas of experimental and theoretical soft matter science and statistical physics.

Naturally, the memories that each author of this foreword has of Gerhard are different. The two people who knew Gerhard for the longest time are Keith and Martin (cf. Figure 2). In both cases, this dates back to the late 1970s. Keith was already a well-established professor of Chemical Engineering at Cornell University then, while Martin was a second-semester student of Chemistry at the Ruhr-Universität Bochum before becoming Gerhard's colleague at the Technische Universität Berlin much later in life. Keith shares with readers of this memorial issue the following personal reminiscences of Gerhard:

I first met Gerhard Findenegg in the late 1970s, while visiting Ruhr-Universität Bochum. His doctoral thesis had been on the topic of calorimetric studies of non-electrolyte solutions, under the supervision of Friedrich (‘Fritz’) Kohler, at the Universität Wien. After receiving his doctorate in 1965 he spent several years as Research Assistant at the Universität Wien, and two years as a postdoctoral fellow at the University of Bristol, with Douglas H. Everett, a well-known expert on physical adsorption. There he worked on the statistical mechanics of chain molecules adsorbed at liquid-solid interfaces. On completing his Habilitation at the Universität Wien, he took up a position as Professor of Physical Chemistry at the Ruhr-Universität Bochum in 1973, and remained there until 1991. Bochum was becoming a centre for research on thermodynamics and statistical mechanics of liquids at the time, counting Gerhard M. Schneider, a world-renowned authority on high-pressure fluid-phase equilibria and supercritical fluid extraction, on its staff. At the Institute of Physics, Johann Fischer, another former doctoral student with Fritz Kohler, was assistant professor, working on the statistical mechanics of adsorption. Not long after Findenegg moved to Bochum, Fritz Kohler left Vienna and joined the Ruhr-Universität Bochum as Professor of Thermodynamics. With the completion of this Viennese trio, Bochum became a center of note in both experimental and theoretical studies of liquids and adsorption.

Somewhat later, in 1984, Findenegg spent a sabbatical at Cornell as Visiting Professor of Chemistry, and I got to know him quite well then. Through several discussions on adsorption and the interfacial phenomena of liquids, I grew to have great respect for his deep insight. While mainly known for his fine experimental work, he had an unusually good knowledge of statistical mechanics and molecular simulation, and this greatly assisted his interpretation of his experimental findings. After he moved to the Technische Universität Berlin (TUB) in 1991, I took the opportunity to visit him when I could, knowing that he would have interesting new research projects and results that meshed with my interests. He had a rather grand suite of offices, which included a conference room, and we would each discuss our recent results and interests. During this discussion, his assistant, Christiane Abu-Hani, would bring us coffee and cookies, something that greatly impressed me, as it would be almost unheard of nowadays in the United States.

Figure 2. Gerhard Findenegg with Keith Gubbins and Martin Schoen (2009).

Starting in 2002 Gerhard would visit us periodically at North Carolina State University (NCSU) to discuss mutual research interests, and this led to our collaborating on the adsorption of non-ionic surfactants on solid adsorbents. Gerhard had discovered that, in contrast to the usual behaviour in which the adsorption decreases with increasing temperature, for non-ionic surfactants the opposite was the case, at least at near-ambient conditions. Henry Bock (a former doctoral student with Martin Schoen), who at the time was a postdoctoral associate with us in Raleigh, set to work to investigate this intriguing finding. Through a combined theory and molecular simulation study [184], we were able to show that this unusual behaviour was an entropic effect that resulted from the breaking of hydrogen bonds between the hydrophilic head of the surfactant molecules and the water solvent as the temperature was raised. In 2005 Gerhard was appointed Adjunct Professor in the Department of Chemical & Biomolecular Engineering at NCSU, and then his visits became more frequent.

In 2009, a joint research programme on ‘Self-Assembled Soft-Matter Nanostructures at Interfaces’ was proposed, involving TUB, the Humboldt Universität zu Berlin, the Max-Planck Institut für Kolloid- und Grenzflächenforschung in Potsdam (Germany), NCSU, the University of Pennsylvania, and the University of North Carolina at Chapel Hill (later joined by Duke University) on the U.S. side. The following year the German team of 11 faculty were awarded a generous grant from the German Science Foundation [International Graduate Research Training Group (IRTG) 1524], and a matching grant was obtained from the U.S. National Science Foundation on the U.S. side. These funds provided for the exchange of doctoral students and faculty over the next nine years (cf. Figure 3). Gerhard was one of the key principal investigators in this effort, collaborating with NCSU faculty on various projects, and welcoming their students to his laboratory in Berlin.

Figure 3. International Research Training Group Meeting, Neuruppin, Germany (2016).

With the advent of the IRTG, he would visit us in Raleigh about once a year. During these visits he was generous with his time, meeting with each of my graduate students and postdocs to discuss their research, and offering helpful suggestions. He was much admired by them as a result of this, and for the kindness and consideration he showed to them. During these visits, my wife Pauline and I would usually go with him to our weekend house on the Pamlico River, where he would go jogging at dawn each day. In addition to his science, he was a convivial conversationalist, and knowledgeable about many subjects. We learned much from him about music, art, and European politics. I remember one year we had gone with him to a concert in Raleigh which featured music by Franz Liszt. Over dinner, Gerhard regaled us with anecdotes about Liszt, who was a leader of the New German School of Music. For some reason the one I recall concerned Brahms, who did not approve of the New School of Music, and regarded Liszt as an upstart of limited talent. He would refer to Liszt as ‘that noisemaker from Weimar’.

Gerhard is greatly missed here. We were privileged to know him.

At about the same time as Keith, Martin became acquainted with Gerhard. Martin's memories of Gerhard as an academic teacher, as a scientist, and as a close friend are the following:

My first experience with Gerhard Findenegg was as a second-semester Chemistry student at the Ruhr-Universität Bochum. It was my first class in Physical Chemistry, and Gerhard taught a course on Phenomenological Thermodynamics. At the beginning of the first lecture a somewhat small, almost dainty, but agile man entered the lecture hall and quickly went to the podium to begin his lecture. After greeting the class in his distinctly Austrian, charming timbre, he quickly glanced at his notes, put them aside, and started his lecture. During the entire presentation he did not look at his notes again but instead presented his material from memory, something I cannot do and never learned to do even towards the end of my own academic career. This style of Gerhard's lecturing persisted throughout the entire semester. We students were also very much impressed by the clarity of Gerhard's writing and drawing on the blackboard. In addition, he succeeded to overcome the proverbial Mathematics phobia of Chemistry students at least to a certain degree. This quality persisted during the Berlin years as I have been told by some of my own doctoral students who occasionally experienced Gerhard in class many years later.

One of my favourite anecdotes involving Gerhard as an outstanding academic teacher happened when I sat next to him during a scientific talk in the lecture theatre in which I used to teach regularly. The lecture hall is equipped with six blackboards, stacked behind each other in two groups of three each. In the morning of the same day, I had been teaching my statistical thermodynamics class and had forgotten to sponge off the two farthest blackboards in the back. They became visible during the discussion following the seminar talk. Suddenly Gerhard turned to me whispering: ‘Did you give a lecture here today?’. I said: ‘Yes, why?’ and he responded, saying: ‘I am concluding this from the very clear and neat writing and the organization of the material on the blackboard.’ To me, this was the greatest accolade from the grandmaster among all the academic teachers I ever came across.

Gerhard was a particularly broad academician with a strong interest in theoretical work while he himself was an excellent and outstanding experimentalist. This breadth is illustrated by his involvement in theoretical courses. Before I was appointed as Professor of Theoretical Chemistry my position was vacant for a number of years. I only found out later that throughout those years Gerhard had been teaching all the courses in Statistical Thermodynamics to keep this topic an active area of teaching in the department. This sense of responsibility and service was always one of his virtues. Anyone getting a hold of a copy of his book on Statistical Thermodynamics (in German with T. Hellweg) [215] will surely find that he truly mastered this field in its entirety.

Because of Gerhard's strong interest in theoretical work, I had the privilege to publish with him on a number of occasions. Gerhard's approach to experimental versus theoretical methods is perhaps best characterized by saying that as an eminent experimentalist he had a deep understanding of the limitations of experiments. He also understood and appreciated the inherent limitations of theory. This quality is rarely met in science and only the greatest of spirits possess it.

The titles of two of Gerhard's publications with me illustrate how he could intertwine experiment and theory. The first example from 2005 is entitled ‘Phase behavior and local structure of a binary mixture in pores: Mean-field lattice model calculations for analysing neutron scattering data’ (with D. Woywod, S. Schemmel, and G. Rother) [162]. It is an attempt to understand the phase behaviour of an isobutyric acid-water mixture in a controlled-pore glass with simple mean-field lattice-gas calculations carried out by my former doctoral student D. Woywod. The second example from 2017 entitled ‘Adsorption and depletion regimes of a nonionic surfactant in hydrophilic mesopores: An experimental and simulation study’ (with G. Rother, D. Müter, and H. Bock) [221] is a piece of work in which we investigated the different behaviour of a short-chain surfactant in porous silica glass by neutron scattering and extensive molecular dynamics computer simulations.

During the Berlin years and especially in the years after Gerhard's retirement he became a close friend of mine and a highly valuable counsellor whenever I found myself in difficult and challenging situations with colleagues. I would then take a particular route for my walk from home to the office. This route would take me to a point from where I could see Gerhard's office window. Usually, after 8am when the lights were on, I called him from my office and asked if he would give me a couple of minutes of his time. We then sat down in his office and I explained the situation. He would listen, think calmly, and then finally give me his point of view and some advice of how the situation could be resolved best. This advice was always extremely helpful especially in politically difficult situations at the university of which I had to master plenty. Because of Gerhard's death, I feel deprived of this advice and sadly miss him as a wise counsellor.

Shortly after the celebration of his eightieth birthday Gerhard became seriously ill and stopped coming to the office regularly. However, we remained in contact by several phone calls throughout 2019. He would not say much about his health because Gerhard was a rather discrete person who did not want to take centre stage with private and personal matters. However, I do recall that these phone calls usually ended by him saying something optimistic like: ‘I will soon be back at the office.’ On 16 November 2019, I called Gerhard on his birthday for the last time. It took quite some time for him to come to the phone and we only talked very briefly but he seemed to appreciate that I called as always during the last few years. However, this time the phone call did not end in the positive and optimistic tone as all the others throughout this final year of Gerhard's life. Instead, he said: ‘Martin, I don't think I will ever come back.’ These were his last words to me.

What I will always remember about Gerhard Findenegg besides all of the other virtues and scientific achievements that we are honouring here is the portrait of a modest, humble, and discrete man, someone who treated others always with politeness no matter what occasion. To me he remains a role model for how you can be a great scientist and a pleasant and enjoyable person at the same time.

Bob Evans and Gerhard became acquainted as a result of their shared interests in the adsorption and wetting of surfaces and interfaces. In particular, Bob was fascinated by Gerhard's important experimental work on critical adsorption, namely how the Gibbs adsorption diverges in the vicinity of the critical point, reflecting the diverging correlation length. Over the years they met on numerous occasions and became personal friends.

Jürgen Rabe also interacted very closely with Gerhard right from the very beginning when Jürgen became a Professor of Polymer Physics at the Humboldt Universität zu Berlin. A couple of years later Jürgen succeeded Gerhard as chairman of the Collaborative Research Center 448 ‘Mesoscopically structured composites’ which Gerhard initiated in 1998. Later, when the International Graduate Research Group 1524 ‘Self-assembled Soft Matter Nanostructures at Interfaces’ was established, with Keith and Martin as co-chairs, Jürgen and Gerhard served on the steering committee for nine years. Jürgen recalls:

My first encounter with Gerhard Findenegg occurred in 1990 through my studies of his insightful papers on the adsorption of long-chain alkanes and amphiphiles from organic solutions to the basal plane of graphite. Particularly interesting for me was his view of the two-dimensional crystallization of molecular adsorbates on the chemically inert and atomically flat graphite surface, because it did not require a lattice match between substrate and adsorbate (Findenegg & Liphard, 1987) [62]. This was very different from what I knew from semiconductor physics with reconstructions at interfaces being key, and it inspired me to draw conclusions on the ‘commensurability and mobility in two-dimensional molecular patterns on graphite’ (Rabe & Buchholz, 1991). In fact, this became the starting point for much more to come. We had home-built a scanning tunnelling microscope (STM), allowing video-rate imaging of molecules at atomic scale resolution. However, the high impact in the long run, had to come from establishing also a very good understanding of the chemical physics of interfaces, which was not really well established in German universities’ physics departments at the time. Physical chemists, therefore, had to teach the up-coming chemical physicists, and Gerhard was very important for me in this regard. This led to the establishment of a highly versatile technique, to investigate hybrid systems from inorganic solid surfaces and molecules. Soon, other (semi-)conducting layered crystals could also be employed and today the technique is applied further to the still growing area of 2D-materials, which now not only serve as substrates but also as covers, forming flexible slit-pores, which may be filled by molecules.

My second encounter with Gerhard Findenegg was a long train ride in the mid-1990s, where we had ample time to talk. Both of us were appointed to Berlin: Gerhard from Ruhr-Universität Bochum to Technische Universität Berlin, and I from Johannes-Gutenberg-Universität Mainz to Humboldt-Universität zu Berlin, which after the German Unification in 1989 had been largely restructured. During this train ride, I got the clear impression that Gerhard Findenegg welcomed me very warmly, even if Humboldt-Universität had now also become a competitor for local resources. It was the start of a wonderful interaction with Gerhard and also polymer scientists in all of Berlin including Freie Universität Berlin, the Federal Institute of Materials Research, as well as in the surrounding State of Brandenburg Universität Potsdam, the newly founded Max Planck Institute of Colloids and Interfaces, and the Fraunhofer Institute for Applied Polymer Research. Notabene, West Berlin had its Berlin Association of Polymer Research, but the new appointees in the east of Berlin and Brandenburg were now also invited, which led to the larger Berlin-Brandenburg Association of Polymer Research (BVP).

With this strength, the next logical step was the formation of a big consortium, to acquire a Collaborative Research Center (CRC), funded by the German Science Foundation (DFG). Its title ‘Mesoscopically Organized Composites’ was ideally suited to the competences of the scientific community in the Berlin-Brandenburg area with its four Universities and the surrounding major research institutes, and also timely in the growing field of nanoscience. The CRC 448 was established in 1998, and of course, Gerhard, the physical chemist became the spokesperson, with A.-Dieter Schlüter, the synthetic chemist from Freie Universität Berlin, as the deputy. From the very beginning, it was planned to switch chairpersons half way through so as to keep the whole community on board. In 2004 it was my pleasure to follow Gerhard in this capacity as chair, and Martin Schoen became vice chair, the two of us reflecting both experiment and theory. Certainly, it has been a gift to succeed Gerhard in this capacity, since the whole scientific structure was carefully considered. I learned a lot from it, and I benefitted from this for other endeavours since then.

Gerhard's impact remains very visible, currently also in a subsequent collaborative research center, CRC 951 on Hybrid Inorganic/Organic Systems for Opto-Electronics with a spokesperson from the next scientific generation, Norbert Koch from Humboldt-Universität zu Berlin. We miss Gerhard as the insightful and caring person he was, but we keep being reminded of him, when we see what came of it.

Matthias Thommes started in Gerhard´s group as Master (Diplom-Chemiker) student, then continued as a doctoral student at the Ruhr-Universität Bochum and finally moved with him to Berlin in 1991. In the early days in Berlin, Matthias assisted Gerhard in building a new research group there. After obtaining his doctoral degree with Gerhard, Matthias spent one and a half years at the University of Maryland at College Park, USA and then took a position in industry in the US where he quickly moved up the ranks to become Scientific Director at Quantachrome Corporation (Boynton Beach, FL), before moving back to academia now as Professor of Chemical Engineering at the Friedrich-Alexander Universität Erlangen. Matthias recalls:

The first time I saw Gerhard Findenegg was in 1984/85 as a student in the second semester of Chemistry at the Ruhr-Universität Bochum. Gerhard was teaching Thermodynamics, which was a mandatory course for all Chemistry students. While I was extremely impressed by the clarity and enthusiasm of his teaching, I could not foresee that a few years later I would be joining his research group, completing both my diploma thesis and PhD thesis under his supervision. However, these first lectures by Gerhard made me interested in Physical Chemistry; in fact, I had come to the Ruhr-Universität Bochum with the goal of majoring in Biochemistry. Finally, I decided to pursue Physical Chemistry and joined Gerhard´s research group in 1988.

During my PhD thesis, we moved with part of our scientific group from Bochum to the Technische Universität in Berlin, as Gerhard had accepted in 1991 the offer to become the Head of the Iwan-N-Stranski Institute (one of the Chairs of Physical Chemistry) of the Technische Universität Berlin. It was an extremely exciting time to be in Berlin, just after the re-unification of Germany, and to have the chance to contribute to the challenging task of successfully setting-up a new research group. To be a student of Gerhard was for me an extremely great privilege and honour. Not only did I learn how to perform careful and reliable experiments, but Gerhard always emphasized the necessity to combine these with theoretical and molecular simulation-based approaches so as to gain a deep understanding of the experimental findings at the microscopic level. This turned out to be an extremely strong fundament to address opportunities and challenges throughout my professional career.

Very often, I think about the frequent scientific meetings with Gerhard during my PhD thesis, which were always a true highlight. At the end of these meetings, I was even more enthusiastic about my research and was full of new ideas. Gerhard Findenegg was a fantastic academic teacher and PhD advisor but also a life-long mentor to me, who would give guidance and advice not only with regard to scientific questions, but also with regard to other important professional questions throughout my career. Gerhard was a true role model not only as a scientist but also as a great person, who always had an open ear for the concerns of his students and co-workers.

Later, when I was working and living with my family in South Florida, Gerhard and Irmgard would visit, often in connection with their visits to North Carolina State University. I am also grateful that Gerhard accepted to lecture at various CPM (Characterization of Porous Materials) symposia (cf. Figure 4), which I co-organized with my colleague Prof. Alexander Neimark from Rutgers University. Since 2012, this symposium is being held on a tri-annual basis in Delray Beach FL. We were thrilled that Gerhard was able to attend the CPM-8 meeting in May 2018, where he delivered a wonderful plenary lecture on a novel method for depositing metal oxide nanoparticles in mesopores via eutectic freezing. He had also served as a member of the Honorary Advisory Committee for this well-established symposium series in the area of adsorption and porous materials characterisation.

Figure 4. Gerhard Findenegg and Matthias Thommes at the CPM-7 Symposium, Delray Beach, Florida, USA (2015).

Gerhard is greatly missed and I am extremely grateful and privileged that I had the opportunity to be his student and then later continued to interact with him on both a personal and professional level.

The Editors of Molecular Physics are very honoured to introduce this memorial issue of the journal celebrating Gerhard Findenegg's scientific achievements. The Chair of Editors, George Jackson, first met Gerhard during a research visit to the group of Ian McLure at the University of Sheffield in the early 1990s; George was a young lecturer at the time and had just become an editor of Molecular Physics. The stimulating series of seminars by Gerhard sparked George's long-time interest in the physical properties and phase behaviour of surfactant systems. The contributions by his collaborators, colleagues, and friends collected in this memorial issue are but a small testament of the highest regard and esteem in which Gerhard is held.

Disclosure statement

No potential conflict of interest was reported by the author(s).