Synthetic Resins as Exchange Adsorbents

Interpretation of NMR Relaxation as a Tool for Characterising the Adsorption Strength of Liquids inside Porous Materials

“…However, all these measurements have limitations, and none are able to probe, non‐destructively, the behaviour of molecules on catalyst surfaces at realistic reaction conditions. For example, whilst isosteric heat of adsorption measurements are non‐invasive,7 they require the determination of adsorption isotherms at different temperatures, and are therefore extremely time‐consuming; characterisation of co‐adsorbed systems may take in excess of well over ten hours 8. TPD is known to cause in situ reactions of some organic molecules leading to dehydration, isomerisation and decomposition, and is also limited in its ability to probe co‐adsorption 9.…”

Laboratory applications of ion exchange techniques.

“…The synthetic anion exchange resins exhibit high exchange capacities and rapid rates of reaction, but are less stable than many of the cation exchange resins, particularly to oxidizing conditions. Nevertheless, they have proved very useful both in laboratory studies and for industrial purposes (2,8,.…”

“…Further studies on the sulfonation of the phenolformaldehyde resins by Holmes (87), Wassenegger, Griessbach and Sutterlin (38), and Wassenegger and Jaeger (89), resulted in the preparation of two general types of cation exchange resins: (1) a condensation product of a sulfonated polyhydric phenol with formaldehyde, having methylene sulfonic acid groups (-CH2-SC>3_); and (2) a condensation product of a sulfonated monohydric phenol with formaldehyde, having nuclear sulfonic acid groups -SO*'. The first type was developed and manufactured in this country by The Resinous Products and Chemical Company and has been described in publications by Myers,el al.…”

“…In choosing an exchanger for any laboratory purpose it should be borne in mind that most available resins are tailor-made for specific industrial purposes. However, the large manufacturers have carried on considerable research on other types of resins with properties vdiich might be more applicable for certain specific purposes (2,8,4) and in many cases small samples of these are available. In the author's experience most of the manufacturers have been very cooperative in furnishing these samples for research purposes; and they have even prepared, upon request, special resins for specified needs.…”

Ion exchange.

“…The organic cation exchangers have certain other advantages, too. They are usually more rapid in their action, and some of them have a much higher capacity than the aluminosilicates; furthermore, they do not impart any trace of silicate to the water passing through them which is an advantage in treating water for highpressure boilers (3,13).…”