Copyright 2009 American Chemical Society
APRIL 7, 2009 VOLUME 25, NUMBER 7
Editorial Neutron Reflectivity Special Issue Dedicated to the Memory of Bob Rowell Earlier this year, we announced some of the upcoming events during the 25th anniversary of the founding of Langmuir, including a special issue edited by Senior Editor Robert Rowell. I am very sad to report that Bob died in January just as he was taking care of the final details of the special issue that follows. Bob was an outstanding editor for Langmuir and someone, as we noted in a special issue honoring Bob (“Bob Rowell Festschrift”, Langmuir 2005, 21(22)), who was active in editing Langmuir since its inception. His death is a great loss for all of us. He is greatly missed. Even as he was weakening during the last days of a long illness, he remained active as an editor. We honor Bob’s distinguished career and his great service to Langmuir by dedicating this special issue on neutron reflectivity as a memorial to Bob. In working with Bob’s dedicated editorial assistants, Janet Hrynyshyn and Connie Laurenitis, we learned that he had prepared a “rough and incomplete draft” of an editorial just a few days before his death. In reviewing it, I find it far from rough and incomplete and felt it appropriate to share with our readers. His draft follows and is itself followed by a preface from Jeff Penfold. David G. Whitten Editorial Light scattering as a noninvasive probe of the fundamental properties of colloids and interfaces has had a long and rich history, far too much to review here. Suffice it to say that the wavelengths of visible light were sufficient to characterize the size of colloidal particles and at the utmost were used to identify the refractive index of the center and an outside layer of the concentric sphere model of a colloid. However, as interest shifted toward nanoparticles and molecular adsorbed layers along with thin films and membranes also involving molecular detail at an interface, much shorter wavelengths were required as a probe. The science has been aided by three developments: high-speed computers, instrumentation for X-ray, and more recently neutron beams and the combination of advances in theory along with translation of the theory into sophisticated computer software to facilitate interpretation of the data. There has been worldwide interest in the new approaches, an example of which is the series on the “buried interface” conducted in Japan since 2001 and published in the Journal of Physics Conference Series. Our special issue may be said to have a history that traces back to the inauguration of ISIS, the Rutherford Appleton Laboratory dedicated to neutron beam studies in 1985. ISIS is not an acronym but rather the name of an ancient Egyptian goddess able to bring the dead back to life. The special issue was stimulated by a symposium, originally planned to honor the retirement of Bob Thomas, but it was broadened to include a 3 day symposium drawing heavily upon ISIS and several neutron facilities in France as well as others in Europe and the United States and elsewhere. Our editorial board offered suggestions for further contributions from those who might not have been able to attend the symposium, and special invitations for contributions were sent. In this issue, you will find many interesting acronyms such as SANS (small-angle neutron scattering), GISANS (grazing 10.1021/la900423w CCC: $40.75 2009 American Chemical Society Published on Web 03/31/2009
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incidence small-angle neutron scattering), and GISAXS (grazing incidence small-angle X-ray scattering) along with supporting and related techniques such as BAM (Brewster angle microscopy) and AFM (atomic force microscopy) to name a few. Also, you may note the diversity of distinguished contributing neutron centers such as ILL (Institut Laue-Langevin), LLB (Laboratoire Leon Brillouin), and, of course, our own NIST. The acronyms of techniques and facilities illustrate the diversity in methodology and beam configurations in the research. It is in the grazing incidence at very small angles that the neutron beams with their very small wavelength are able to probe molecular detail at interfaces, especially because of the measurement of the scattering length density that is sensitive to the lighter elements of hydrogen, carbon, nitrogen, oxygen, and so forth. X-rays are sensitive to electron density whereas neutrons impinge upon the nuclei and their isotopes. The chemistry of isotopic substitution adds to the ability to probe molecular detail at an interface. Robert L. Rowell LA900423W
Editorials
