Martin Plassen

Combinatorial chemistry – The emperor's new clothes?

Considering the increasing pressures and constraints on research and development towards focussed innovation, the prospects of new fast and cost-effective approaches addressing the many challenges faced in more rapidly developing next generation products are expected to be very significant. The application of the new methodologies of combinatorial chemistry to materials discovery and development, though facing special challenges, has now been demonstrated in the hydrothermal synthesis of a series of aluminophosphate materials. Using this approach an extensive study of complex multi-component systems was easily achieved, demonstrating the highly reproducible experimental conditions that allows efficient screening of phase composition based on X-ray diffraction analysis.

Combinatorial hydrothermal synthesis of titanium zinc silicates

Abstract Combinatorial approaches were applied to screen the alkaline part of the quaternary ZnO-TiO 2 -SiO 2 -NaOH/KOH phase diagram, in the presence and absence of additional compounds—HF or TEAOH. In addition, the effects of synthesis time and temperature on the Ti-containing system were examined. Combinatorial syntheses in the presence of concentrated HF were successfully performed. Synthetic routes to zinc silicate and titanosilicate framework structures with 3- and 4-membered rings were established and efficiently mapped in ternary phase diagrams. The aim of the mapping was to investigate the compositional space where highly substituted metallosilicates may form; this composition area has not been investigated in a systematic way before. Zn-silicates with the composition Si/Zn=3.5 (VPI-7) and Si/Zn=1 (Na 2 ZnSiO 4 (HT) and NaZnSiO 3 (OH)) was reproduced, but no phases with the intermediate target composition Si/Zn=2.0 appeared. The addition of HF prevents formation of quartz, while TEAOH only has minor or no effect on the syntheses. The addition of titanium to the ZnO-SiO 2 -NaOH system leads to formation of titanosilicates with Si/Ti=2.4 and 1.0, but again no intermediate compositions appeared. Formation of the zinc silicate VPI-7 was suppressed and formation of ternary titanium zinc silicates was not observed.

An up-to-date automated instrument for the characterization of microporous/mesoporous solids

A high vacuum gravimetric system for measuring adsorption and desorption processes is presented. The system has been constructed using the newest technology, both with regard to the instrument hardware and software. This provides a system working over a wide pressure range, able to implement small pressure steps and monitor small weight changes, all continuously under the control of a computer through a modern graphical user-interface. The use of a microbalance allows measurements from gases and liquids with saturation pressures as low as 1 mbar. Great flexibility of the system has been maintained, both in terms of the hardware and the software, allowing easy reconfiguration to the special requirements of the particular experiment. An example is the availability of a Fourier transform infrared (FTIR) instrument which allows the simultaneous generation of IR spectra of the adsorbed surfaces species under the same pressure and temperature conditions as the isotherm develops. The function of the system is il...

03-P-18-Mixed alkali templating in the Si/Al=3 and 10 systems: a combinatorial study

Publisher Summary This chapter discusses a combinatorial approach that is used to investigate mixed alkali templating in the silicon/aluminium (Si/A1) = 3 and 10 zeolitic systems. The experimental design includes 15 high-symmetry alkali combinations of Li + , Na + , K + , and Cs + , decoupled variations in total hydroxide and total alkali, and four digestion conditions giving 960 reactions. Compositional fields for BEA, ANA, MER, LTL, and pollucite (ANA-Cs), interactions between alkali cations in the templating process, and the use of principle components analysis to streamline the analysis of large X-ray diffraction (XRD) data sets are presented.