N e w s a n d V i e w s

researchers sugges ted tha t this was probably due to the acidic c leaning agent ' s abil i ty to dissolve inorganic deposi ts on the membrane . After cleaning with the acidic cleaning agent the cake of deposi ts on the m e m b r a n e became more porous. Dur ing filtration of pure water the cake was compressed, hence the flux was t ime-dependent .

However, the r e sea rcher s s ta ted tha t alkal ine cleaning agents not only dissolve organic deposits , bu t have a positive effect on the m e m b r a n e itself.

Further information from: A.-S. donsson, Department of Chemical Engineering I, Lund University, P.O. Box 124, S-221 OO Lund, Sweden.

Study of hollow fibres modif ied by dimethylolurea polymers The syn thes i s of modified polysu lphone ul t raf i l t rat ion hollow fibre m e m b r a n e s and s tudies on these m e m b r a n e s by XPS spect roscopy are descr ibed in a paper in J. Appl. Polym. Scl. (51, pp 1183-1187, 1994).

The mos t ser ious operat ional cons t ra in t in the use of biological solut ion ul t raf i l t rat ion with polysulphone m e m b r a n e s is tha t of fouling. This behaviour is often ass igned to the hydrophobic charac te r of the polysulphone tha t involves nonselect ive adsorpt ion of prote ins onto the membranes . To limit th is problem the surface hydrophfl ici ty is increased, for example by su lphona t ion of polysulphone, or coat ing with hydrophil ie components or surfac tant .

Polymers obta ined by po lycondensa t ion of d imethylo lurea (DMU) coated onto polysulphone m e m b r a n e s should give good hydrophfl icl ty because DMU has carbonyl and hydroxy funct ional groups. Depending on the react ion conditions, polymers on the surface p resen t a gel or a film form, called 'ge l -suppor ted ' and 'coated' , respectively. The aim of these s tudies was to de te rmine if po lyeondensa t ion on the m e m b r a n e modified the final form of the polymer. Modified and unmodif ied polysulphone m e m b r a n e s were ana lysed by XPS spectroscopy.

The modificat ion observed on a modified m e m b r a n e was s tudied by reference to a previous article deal ing with XPS analys is of gel and film DMU polymers (also pub l i shed in J. Appl. Polym. Sci.). The resea rchers found tha t ge l - suppor ted m e m b r a n e s are modified by a polymer of fi lm-type chemical s t ructure . Also, they concluded tha t the na tu re of the support , polysulphone, does not affect the final form of the polymer.

Further information from: P. Rouzies, Laboratoire de Traitements Physico-Chimiques des Eaux / Departement GPI, INSA, Complexe Scientifique de Rangueil, 31 077 Toulouse Cedex, France.

Call for papers for biofunctional membranes conference The first a nnounc e m e n t and call for pape r s has been pub l i shed for the In te rna t iona l Conference on Biofunctional Membranes to be held from 9-11 October 1994, a t the Universi ty of Kentucky Center of Membrane Sciences in Lexington, Kentucky, USA.

Biofunctional m e m b r a n e s are enti t ies in which a biomolecule, a collection of biomolecules or cells, are incorpora ted into a polymeric mat r ix cas t in the form of membranes . The conference will highlight the mos t cur ren t ins ights into the s t ruc ture , function, and appl ica t ions of biofunct ional m e m b r a n e s including synthesis , s t ruc ture , and appl ica t ions to catalysis (bioreactors), b iosepara t ions (affinity membranes) , recognit ion and b ioanalys is (biosensors and m e m b r a n e - b a s e d imprinting), and to medical uses (artificial organs, etc).

On 9 October, a tutor ial on biofunct ional membranes will be held. Various topics will be covered, among which are: s t ruc tu re and function re la t ionships in biofunct ional membranes , biosensors , affinity membranes , r ad iopha rmaceu t l ca l uses of biofunct ional membranes , a n d biofouling.

The deadl ine for receipt of abs t r ac t s is 1 Ju ly 1994. Further information from: Prof D. Allan Butte[field,

International Conference on Membranes, c / o Conferences and Institutes, 218 Peterson Service Building, University of Kentucky, Lexington, KY 40506-0005, USA. Tel: +1 606 257 5875. Fax: +1 606 323 1053.

Services provided for whey process ing plants Ionics has finalized a contract to provide whey process ing services to Mid-America Dairymen, Inc, one of the USA's largest dai ry cooperatives. Under the contract Ionics will provide equ ipment and services including oversight of whey process ing operat ions, at Mid-America 's whey process ing p lan t s located at Monett, Missouri and Fergus Falls, Minnesota.

Ionics' Cha i rman and CEO said tha t the agreement with Mid-America p resen ted the first oppor tuni ty for Ionics to use its expert ise in m e m b r a n e - b a s e d sys tems to provide process ing services to the whey industry.

Further information from: Ionlcs Inc, 65 Grove Street, Watertown, MA 021 72, USA. Tel: +1 617 926 2500.

2 M e m b r a n e Technology No. 46