Preparation And Properties Of Polyvinyl Chloride Hollow Fiber Composite Membrane

As the intermediate membrane technology between ultrafiltration and reverse osmosis, nanofiltration (NF) has been widely used for many applications like water treatment. It is very urgent to prepare high-performance nanofiltration membranes because it is the core of the nanofiltration process. Here, we prepared three kinds of PVC based nanofiltration membranes via typical interfacial polymerization (IP), amination IP and freezing IP, respectively.NF-PVC membranes were fabricated via IP of PIP and TMC on PVC substrate. The sweeping process after amine aqueous solution infiltration was studied minutely. The sweeping conditions affect the membrane performance via influence on the actual concentration of PIP layer on substrate and the integrity of composite layer. When tested at 0.35MPa, room temperature, the membrane had an MgSO4 rejection of 96.0% and a flux of about 24.1 L·m-2·h-1. Furthermore, the membrane exhibited excellent separation performance towards hardness ions, heavy metal ions and potential organic pollutants.A composite membrane consists of a positively charged interlayer sandwiched between substrate and negatively charged outermost surface was reported for the first time. A facile method for preparing the dual charged composite layer NF membranes via amination-IP on PVC substrate is presented. The re-structured membrane exhibit super-high multivalent salts rejection and a reasonably high flux. The excellent rejection performance should be attribute to the co-separation of the dual charged composite layers. The promising preliminary results in this study provide a useful platform to promote the separation performance of NF membrane. The as-prepared membranes with super-high multivalent-salt rejection are also promising in application in drinking water treatment and pretreatment of RO seawater desalination.To slow down the rate of the IP reaction, freezing process was introduced after anime aqueous solution infiltration. Nanofiltration membranes fabricated via freezing IP exhibited an MgSO4 rejection of 96.0% and doubled flux of 52 L·m-2·h-1 when testing at 0.35MPa. Moreover, the as-prepared nanofiltration display a relatively smooth outermost surface indicating a good antifouling performance.