Andrzej I. Lachowski

Thermostability and esterification activity ofMucor javanicus lipase entrapped in silica aerogel matrix and in organic solvents

The lipase ofMucor javanicus (nowM. circinelloides) entrapped in silica matrix by the sol-gel method esterified primary and secondary alcohols with conversions ranging from 30 to 35% and 10 to 15%, respectively. Loss in activity of the preparations after incubation at 100°C for 1 h with petroleum ether, dodecane, 1-heptanol or oleyl alcohol was about half of that observed for the native lipase.

Two-component aerogel adsorbents of water vapour

Abstract Two-component SiO2–CaCl2 or SiO2–LiBr aerogels exhibit outstanding adsorption capacities of water vapour, in the range of 0.9–1.1 kg H2O/kg adsorbent. Adsorption properties remain stable during repeated adsorption/desorption cycles.

Effect of drying with supercritical carbon dioxide on enhancement and modification of polymeric catalysts' activity

The aim of the work is to investigate the effect of drying raw polymeric catalysts in supercritical carbon dioxide to achieve catalysts of improved performance

Activated carbons from crosslinked Novolac resin

Activated carbons were prepared from well-characterized Novolac resin cured with various amounts of hexamethylenetetramine (HMTA). The process consisted of curing the resin with HMTA at 200°C, carbonization in nitrogen at 600°C and gasifying the char in carbon dioxide or in steam at 900°C. The influence of the amount of HMTA used for curing on the yield and the characteristics of the activated carbon was investigated. The pore volume attained a maximum for Novolac initially cured with ca. 2 wt% HMTA. Further increase in the amount of HMTA used for curing resulted in an increase in the yield of active carbon, but the susceptibility to carbon dioxide activation decreased. Relative to carbon dioxide, the use of steam generated a narrower, but more extensive, microporosity in the char obtained from cured Novolac resin.

Preparation effects on titania-sulfate aerogel morphology

Abstract Institute of Chemical and Process Engineering, Faculty of Chemistry, Silesian Technical University, 44–100 Gliwice, Ks. M. Strzody 7, Poland The presence of sulfate ions markedly affects the nanopore structure of titania-sulfate aerogels. In TiO 2 -SO 4 2− materials, unlike in zirconia-sulfate aerogels, the larger sulfate load stimulates formation of a more consolidated structure. The XRD analysis shows that even a crystalline phase (anatase) may be present in fresh, dry aerogels, which, perhaps, is the first observation of this phase in sol-gel titania obtained from the low temperature drying process.

Effective sol-gel adsorbents of water vapor prepared using ethyl silicate 40 as a silica precursor

Abstract Effective composite sol-gel adsorbents of water vapor can be prepared in a one-step procedure using ethyl silicate 40 as a cost-effective silica precursor. Adsorption properties exhibited by the materials thus obtained are comparable with those of the samples obtained from the more complex procedure developed previously which made use of tetraethoxysilane.