A highly performing and durable forward osmosis (FO) membrane was prepared using a polydopamine-modified polyolefin (DPO) support via an aromatic solvent (toluene)-based interfacial polymerization (IP). The hydrophobic polyolefin support was uniformly hydrophilized by polydopamine coating, which provided long term operation stability. In addition, a highly permselective selective layer was prepared on the hydrophilic DPO support by the toluene-based IP, which promoted amine diffusion and the subsequent IP reaction. As a result, the prepared DPO-supported TFC membrane exhibited significantly high FO performance, which was ~4.9 times higher FO water flux and ~62% lower specific salt flux than those of a commercial FO (HTI-CTA) membrane in FO mode. Furthermore, its excellent mechanical and chemical stability enabled stable operation.

We report on the fabrication of a high performance reverse osmosis membrane based on a hydrophilic polyacrylonitrile support via an aromatic solvent-assisted interfacial polymerization process. The use of aromatic solvent (toluene or xylene) produced the membranes with unprecedentedly high NaCl rejection (~99.9%) and superior water flux, outperforming both the control membrane prepared using a conventional aliphatic solvent (n-hexane) and commercial membranes. The membranes fabricated using toluene or xylene had roof-like structures covering a thin and highly dense polyamide (PA) layer, which was induced by enhanced amine diffusion and the extended miscible layer resulting from the increased miscibility of aromatic solvent with water. The high performance of the membranes is attributed to thin and highly cross-linked basal PA layer.

The highly performing polyamide (PA) thin film composite (TFC) reverse osmosis (RO) membrane was prepared using the commercialized porous polyolefin (PO) membrane as a support. The PO-supported TFC (PO-TFC) membrane was fabricated via a conventional interfacial polymerization process. The highly permselective PA layer was formed by optimizing membrane fabrication parameters such as monomer/additive composition and post-treatment. The uniform pore structure and high surface porosity of the PO support are beneficial for improving the membrane permselectivity. As a result, the prepared PO-TFC membrane showed ~30% higher water flux and ~0.4% higher NaCl rejection compared to a commercial RO membrane. In addition, the PO-TFC membrane exhibited excellent mechanical properties and organic solvent resistance.

A porous polyolefin (e.g. polypropylene and polyethylene) membrane has been commercialized as a lithium ion battery separator. The highly performing thin film composite (TFC) forward osmosis (FO) membrane was fabricated using the porous polyolefin membrane as a support via typical interfacial polymerization process. A very thin thickness (~8 μm) and highly interconnected pore structure of the polyolefin support can greatly reduce the internal concentration polarization, leading to high water flux, as evidenced by its low structural parameter (~168 μm). The prepared polyolefin-supported TFC membrane showed ~3.7 times higher water flux and ~33% lower specific salt flux compared to HTI-CTA commercial FO membrane with 1.0 M NaCl draw solution and DI water feed solution in FO mode. In addition, its excellent mechanical strength enables stable membrane operation.

Thin-film composite (TFC) membrane is currently the most widely used membrane structure for reverse osmosis (RO) process. Most commercial membrane for RO consisted of porous support layer and dense polyamide permselective layer, yet the polyamide layer has a very rough surface morphology and considerable thickness, and these features are intrinsic properties of current RO membrane fabrication process. In this study, we present the new membrane fabrication, named layered interfacial polymerization (LIP). LIP could control the roughness and thickness of permselective layer without complicated process or significant membrane performance loss, and the performance itself was comparable to conventional IP membrane. Moreover, the fabricated membrane has a remarkable antifouling ability possibly due to the unique smooth morphology.

We report on a new fabrication method of polyamide thin film composite RO membranes, so called support-free interfacial polymerization (SFIP). In SFIP method, the PA layer is first formed at the interface without a porous support, and then adhered onto a support unlike conventional IP where the PA layer is in-situ formed directly on a support. We control the surface chemistry of a PAN support by adjusting hydrolysis to maximize adhesion of the PA layer with the support. The SFIP-assembled membrane showed higher performance and unique surface morphology compared to conventional IP-assembled one. It allows facile characterization of the PA layer and PA-support interface together with well-defining each component. Therefore, SFIP provide an promising material platform for the fabrication of RO membranes and fundament study.

본 연구는 속리산국립공원 내 쌍곡계곡에 분포하는 식물상을 조사하기 위해 수행되었고 조사기간은 2006년 3월부터 2007년 6월까지 조사하였다. 식물상을 조사한 결과, 88과 242속 342종 52변종 7품종 등 총 401분류군이 확인되었다. 한국특산식물은 개비자나무, 키버들, 개족도리, 할미밀망, 민산초나무, 청괴불나무, 병꽃나무, 분취 등 총 8분류군이 조사되었다. 환경부 지정 멸종위기식물은 망개나무 등 1분류군이며, 산림청 지정 희귀식물은 개족도리, 고란초, 망개나무, 백작약, 태백제비꽃, 꼬리진달래, 말나리 등 7분류군이 조사되었다. 이들의 보전을 위해서는 향후 희귀식물에 대한 구체적인 보전방안과 번식방법 등이 논의되어야 할 것으로 판단된다. 자원식물은 관상용 식물 220분류군, 식용 식물 239분류군, 약용 식물 281분류군, 기타용 식물 206분류군으로 나타났다. 귀화식물은 오리새, 소리쟁이, 취명아주, 아까시나무, 붉은토끼풀, 토끼풀, 큰달맞이꽃, 비짜루국화, 붉은서나물, 개망초, 망초, 뚱딴지, 서양민들레 등 13분류군이 관찰되었으며, 귀화율은 약 3.24%, 자연파괴도는 약 4.53%로 나타났다.