The effect of heavy metal ions on the oxidation of cellulose triacetate membranes

Acute Onset of Decreased Vision and Hearing Traced to Hemodialysis Treatment With Aged Dialyzers

“…18 The additional recommendation that dialyzers be stored under cool and dry conditions will also minimize degradation. [19][20][21][22][23] Under such conditions, chain scission is the major degradation route, but deacetylation can occur over time if the dialyzer membrane was inadvertently exposed to a solution of pH less than 4 during manufacturing. At ambient temperatures, these reaction rates are slow, so long periods are required to allow the deacetylated degradation products to accumulate.…”

Characterization of new and fouled SWRO membranes by ATR/FTIR spectroscopy

“…Reverse osmosis desalination plant in Jeddah (Phase I) has been in operation since 1989, and it was discovered that due to chlorine attack, quality of permeate deteriorated (David 1991;Green et al 2011). Chlorinated sea water also contains trace metals (Fujiwara et al 1994;Kumano et al 1994), which may either accelerate or retard the degradation of membrane due to their presence with residual chlorine. The presence of trace metals in water may yield a variety of oxidizing and/or reducing species, which may also be responsible for oxidation of membrane.…”

Polymer inclusion membrane based on cellulose triacetate (CTA) plasticized with 2-nitrophenyl octyl ether

“…Na podstawie danych literaturowych [28,29] doty-cz¹cych w³aoeciwooeci fizykochemicznych trioctanu celulozy mo¿na s¹dziae, ¿e ograniczenie szybkooeci i efektywnooeci procesu rozdzia³u w obecnooeci jonów Cr(VI) mo¿e byae zwi¹zane z degradacj¹ struktury membrany inkluzyjnej z CTA.…”

“…Trioctan celulozy (CTA), stanowi¹cy matrycê polimerowej membrany inkluzyjnej, jest podatny na dzia³anie czynników utleniaj¹cych oerodowiska [29]. Mo¿liwe wiêc, ¿e jony Cr(VI), o silnie utleniaj¹cych w³aoeciwooeciach, mog¹ niszczyae polimerow¹ matrycê z CTA.…”

“…Rysunek 8b obrazuje polimerow¹ matrycê z CTA namoczon¹ w roztworze jonów Cr(VI), z widocznymi nieodwracalnymi zmianami morfologicznymi na jej powierzchni. Silnie utleniaj¹ce dzia³anie jonów Cr(VI) mo¿e powodowaae hydrolizê grup acetylowych lub utlenianie ³añcucha polimeru, a w konsekwencji jego rozrywanie [28,29]. Uznaje siê, ¿e g³ównym procesem przyczyniaj¹cym siê do degradacji CTA jest utlenianie ³añcucha polimeru, w wyniku którego nastêpuje zmniejszenie ciê¿aru cz¹steczkowego i wytrzyma³ooeci mechanicznej polimeru.…”