Recently, Graphene Oxide (GO) has extensively studied as a membrane material due to its 2D structure and high CO2 sorption property, however, GO membrane still has challenging issues; low gas permeability to apply to practical system and low stability under dry condition. In this study, we introduced GO as a nanofiller in CO2-philic polymer matrix because GO has molecular sieving property and 2D structure. First, we mixed two kinds of PEO-containing polymers by controlling the ratio of free volume in polymer networks to increase the permeability, and then, we added GO in the mixed polymer matrix for improving the CO2/N2 selectivity. Finally, we fabricated GO-incorporated mixed matrix membranes with high CO2/N2 separation performance beyond the upper bound. High long-term stability and high CO2/N2 selectivity were also achieved in mixed gas system.

The gas separation through membrane is considered as a promising solution for the stabilization of greenhouse gas level of atmosphere attributed from CO2. The separation process of membrane allows low energy requirement, low cost, and ease of operation. However, conventional polymeric membranes generally suffer from the trade-off between permeability and selectivity, which remains as one of the most important challenges for commercialization. Mixed matrix membranes (MMMs), consisting of a polymer matrix and porous nano-filler, are considered to be a promising solution to overcome the trade-offs in polymeric membranes. Herein the porous nano-structures were fabricated to enhance the permselectity of CO2 separation membranes. The MMM which were fabricated with prepared porous nano-filler showed permeability improvement without significant selectivity loss.

올레핀/파라핀 분리는 산업에서 가장 중요하고 도전적인 분리 이슈 중의 하 나이다. 흡착 및 막은 에너지 절약적 분리 기술이기에 올레핀/파라핀 분리를 위한 흡착 및 막 기술의 개발이 많은 관심을 받고 있다. 본 연구에서는 유무기 하이브리드 세공체(metal-organic framework, MOF)의 기공 내부에 올레핀 분자와 π complexation이라는 특별한 인력을 지니는 Cu 1가 이온을 효율적이며 안정적으로 함침하는 방법을 제시하였다. 또한, Cu 1가 이온이 함침된 MOF를 고분자 막과 결합하여 올레핀 선택 분리용 혼합기질막(mixed matric membranes)을 성공적으로 개발하였다.

For possibility of specific gas sieve and adsorption, metal organic framework has attracted expectation in the gas separation field. But, this enhances gas transport performance only at high loading. So we designed effective composite growing MOF on porous 2D template to improve membrane at low concentration. The mixed matrix membranes showed improved CO2 permeability drastically by improved CO2/N2 diffusion selectivity and showed anti-plasticization effect.

The mixed matrix membranes for CO2/N2 separation, which is composed of commercially available MgCO3 and amphiphilic comb polymer matrix based on poly(ethyleneglycol) behenyl ether methacrylate and poly(oxyethelene methacrylate) synthesized via a facile free radical polymerization, were fabricated. The use of a CP improved the dispersion of the MgCO3 in ethanol due to the specific interaction between CP and MgCO3. The MMMs were characterized using scanning electron microscopy(SEM), high-resolution transmission electron microscopy(HR-TEM), and wide-angle X-ray scattering (WAXS). The best performance of gas separation for CP/MgCO3 MMM was shown in the case of 45wt% MgCO3 with the highest CO2 /N2 selectivity(93.8) and good CO2 permeance (30.9GPU). This performance of this CP/MgCO3 MMM is higher than other MgCO3 commercially available MMMs.

In this study, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT-PSS) was introduced into polymer gas separation membrane. The composite membrane consisted of poly(2-[3-(2H-benzotriazol –2-yl)-4-hydroxyphenyl] ethyl methacrylate)-poly(oxyethylene methacryalate) (PBEMPOEM) comb copolymer matrix and PEDOT-PSS filler. PEDOT-PSS has strong ionic bonding interaction between PEDOT and PSS, and sulfonic acid groups in PSS interact with water molecules with hydrogen-bond. Because of these specific properties, the incorporation of PEDOT-PSS could form CO2 pathway for gas transport through the membrane. PEDOT-PSS chains were homogeneously dispersed in the PBEM-POEM matrix as a network. The best performance of prepared PEDOT-PSS/PBEM-POEM composite membranes was CO2 permeability of 59.6 Barrer with a CO2/N2 selectivity of 77.4, being close to the 2008 Robeson upper boundlines.

Recently, the ZIF-67 molecular sieve has emerged as an excellent substitute for the ZIF-8 counterpart due to its potentially high propylene/propane separation performance. Here, for the first time, we investigated the effect of ZIF-67 molecular sieves in mixed matrix membranes (MMMs) for propylene/propane separations by integrating them into 6FDA-DAM polymeric matrix. A thorough investigation on gas transports elucidated that size-based energetic selectivity is a major contributor for the high propylene/propane diffusivity in ZIF-67 containing MMMs. Lastly, the defect-free incorporation of ZIF-67 nanoparticles into 6FDA-DAM polymer matrix effectively retarded physical aging process compared to bare 6FDA-DAM membrane.

Recently, the Co-ZIF-8 molecular sieve has emerged as an excellent substitute for the ZIF-8 counterpart due to its potentially high C3H6/C3H8 separation performance. Here, for the first time, we investigated the effect of ZIF-67 molecular sieves in mixed matrix membranes (MMMs) for C3H6/C3H8 separations by integrating them into 6FDA-DAM polymeric matrix[1]. Our current work demonstrated the superior C3H6/C3H8 separation performance of 6FDA-DAM/ZIF-67 MMMs, which was achieved mainly by the excellent size-based energetic selectivity of Co-ZIF-8 molecular sieves. Also, Co-ZIF-8 containing MMMs exhibited excellent physical aging resistance, further ensuring its potential application of the industrial C3H6/C3H8 separations.

Biodegradable epoxy (B-epoxy) was prepared from diglycidyl ether of bisphenol A and epoxidized linseed oil. The mechanical properties of B-epoxy composites reinforced with multi-walled carbon nanotubes (MWCNTs/B-epoxy) were examined by employing dynamic mechanical analysis, critical stress intensity factor (KIC) tests, and impact strength tests. The electromagnetic interference shielding effectiveness (EMI-SE) of the composites was evaluated using reflection and absorption methods. Mechanical properties of MWCNTs/B-epoxy were enhanced with an increase in the MWCNT content, whereas they deteriorated when the MWCNT content was >5 parts per hundred resin (phr). This can likely be attributed to the entanglement of MWCNTs with each other in the B-epoxy due to the presence of an excess amount of MWCNTs. The highest EMI-SE obtained was ~16 dB for the MWCNTs/B-epoxy composites with a MWCNT content of 13 phr at 1.4 GHz. The composites (13 phr) exhibited the minimum EMI-SE (90%) when used as shielding materials at 1.4 GHz. The EMI-SE of the MWCNTs/B-epoxy also increased with an increase in the MWCNT content, which is a key factor affecting the EMI-SE.

Flavonoid myricetin, usually found in tea and medicinal plants, has antioxidant and anti-inflammatory effects. Our objectives in this study were to verify the effects of myricetin on periodontal ligament fibroblasts (PDLFs) under inflammatory conditions and to observe its effects on osteoclast generation and on cytokine expression in RAW264.7 cells. To determine the effects of myricetin on PDLFs, we examined the expression and activity of proteolytic enzymes, including MMP-1, MMP-2, and MMP-8, which all play an important role in chronic periodontitis. We observed the effects of myricetin on intracellular signal transduction to verify the molecular mechanism involved. By measuring the formation of TRAP–positive multinucleated cells and the expression and activity of MMP-8, we were able to assess the effects of myricetin on osteoclast generation. In addition, by measuring the secretion of IL-6 and NO, we could evaluate the effects of myricetin on inflammatory mediators. We found that Myricetin had no effect on the viability of the PDLFs in the presence of inflammation, but it did decrease both the expression of MMP-1 and MMP-8 and the enzyme activity of MMP-2 and MMP-8 in these fibroblasts. Myricetin also decreased the lipopolysaccharide-stimulated phosphorylation of JNK, p38 signaling, IKKB, AKT, and p65RelA in the PDLFs. In the RAW264.7 cells, myricetin inhibited both the expression and the activity of MMP-8. Furthermore, Myricetin not only suppressed the generation of LPS-stimulated osteoclasts, but it also slightly inhibited LPS-stimulated degradation of IkB and decreased the release of LPS-induced IL-6 and NO. These findings suggest that myricetin alleviates the tissue-destructive processes that occur during periodontal inflammation.

In this work, the effects of maleic anhydride (MA) content on mechanical properties of chopped carbon fibers (CFs)-reinforced MA-grafted-polypropylene (MAPP) matrix composites. A direct oxyfluorination on CF surfaces was applied to increase the interfacial strength between the CFs and MAPP matrix. The mechanical properties of the CFs/MAPP composites are likely to be different in terms of MA content. Surface characteristics were observed by scanning electron microscope, Fourier transform infrared spectroscopy, and single fiber contact angle method. The mechanical properties of the composites were also measured by a critical stress intensity factor (KIC). From the KIC test results, the KIC values were increased to a maximum value of 3.4 MPa with the 0.1 % of MA in the PP, and then decreased with higher MA content.

Polyethersulfone (PES) 고분자 상변환막의 성능을 향상시키기 위해 PES 고분자에 나노 크기의 ZnO 무기입자를 함침시킨 혼합기질막(mixed matrix membrane)을 제조하고 특성을 평가하였다. PES-ZnO 혼합기질막은 ZnO 나노입자를 PES 대비 최대 0.375 wt%의 낮은 비율로 첨가시킨 PES-ZnO-NMP(N-methyl-1-pyrrolidone)로 이루어진 캐스팅 용액을 사용하여 상변환법을 통해 제조하였다. 제조된 혼합기질 막의 물성과 특성은 막의 단면구조 관찰, 접촉각 측정, 인장강도 측정, 순수 투과량 측정 및 BSA 단백질 용액의 한외여과 실험을 통해 평가하였다. 이 결과 혼합기질 막은 PES 고분자 matrix에 함유된 ZnO 나노입자로 인해 막의 친수성이 증가하여 막오염 발생이 억제되어 투과량이 증가하였다. ZnO 나노입자는 혼합기질막의 제조에 있어 막오염의 발생 억제와 투과량 증가에 유용하게 사용될 수 있는 무기물 첨가제임을 알 수 있다.

PEBAX®는 폴리에테르가 우수한 CO2용해도를 나타내어 기체분리막의 소재로 주목받고 있지만 폴리아마이드의 crystallinity로 인해 투과성능면에서 제약을 받는다고 알려져 있다. 본 연구에서는 PEBAX® 막의 기체투과특성을 향상시키기 위해 합성된 aluminosilicate hollow nanoparticles를 막 내부에 고르게 분산시켜 함량별로 혼합막을 제조한다. 분산된 나노입자의 함량에 따른 CO2 용해도 증가, 확산 속도의 증가로 인하여 선택도와 투과도의 향상을 예측할 수 있다. 첨가된 나노입자의 morphology와 yield를 확인하고, 첨가량이 증가할수록 선택도의 변동없이 투과도가 증가하는 것을 알 수 있다.