Azari Sara, Zou Linda, Cornelissen Emile
SA Water Centre for Water Management and Reuse, University of South Australia, Adelaide 5095, SA, Australia.
SA Water Centre for Water Management and Reuse, University of South Australia, Adelaide 5095, SA, Australia.
Colloids Surf B Biointerfaces. 2014 Aug 1;120:222-8. doi: 10.1016/j.colsurfb.2014.03.028. Epub 2014 May 22.
Theoretical predictions of interaction energies for membrane-biopolymer foulant pairs were used to compare the fouling tendencies of a virgin commercial polyamide reverse osmosis (RO) membrane with a amino acid 3-(3,4-dihydroxyphenyl)-l-alanine (l-DOPA) coated RO membrane. Lifshitz-van der Waals (LW) and Lewis acid-base (AB) surface tension components of the membranes were determined based on contact angle results using the van Oss approach. From these values, the LW and AB components of the free energy of adhesion between membrane and foulants were calculated. Electrostatic (EL) double layer interaction energies between the membrane and foulants were also estimated using the measured surface charge data of the membranes and fouling agents. Bovine serum albumin (BSA) and alginic acid sodium salt (alginate) were used as model biopolymers causing membrane fouling. Based on the calculated adhesion free energies, acid-base interactions were found to have the strongest impact on the adhesion of both BSA and alginate to the either membranes surfaces. It was found that l-DOPA modification has significantly lowered acid-base interaction affinity toward the adhesion of both foulants studied. On the basis of calculated free energies of adhesion, lower fouling tendency of the l-DOPA modified membrane was expected. The accelerated fouling tests indicated a lower flux decline rate for the modified membrane and confirmed the results obtained from theory.
利用膜 - 生物聚合物污垢对相互作用能的理论预测，比较了未使用过的商用聚酰胺反渗透（RO）膜与涂覆了氨基酸3 -（3,4 - 二羟基苯基）-L - 丙氨酸（L - DOPA）的RO膜的污染倾向。基于使用范奥斯方法的接触角结果，测定了膜的 Lifshitz - 范德华（LW）和路易斯酸碱（AB）表面张力成分。根据这些值，计算了膜与污垢之间粘附自由能的LW和AB成分。还使用测得的膜和污垢剂的表面电荷数据估算了膜与污垢之间的静电（EL）双层相互作用能。牛血清白蛋白（BSA）和海藻酸钠盐（藻酸盐）用作导致膜污染的模型生物聚合物。基于计算出的粘附自由能，发现酸碱相互作用对BSA和藻酸盐与任一膜表面的粘附影响最大。发现L - DOPA改性显著降低了对所研究的两种污垢粘附的酸碱相互作用亲和力。基于计算出的粘附自由能，预计L - DOPA改性膜的污染倾向较低。加速污染试验表明改性膜的通量下降速率较低，并证实了从理论上获得的结果。
