표제지
ABSTRACT
목차
Nomenclature 13
제1장 서론 15
제1절 연구 배경 및 목적 15
제2장 이론적 배경 18
제1절 그래핀 18
1. 그래핀의 구조 및 특징 20
2. 그래핀 제조법 21
3. 그래핀 옥사이드 (GO, graphene oxide) 25
4. 환원 그래핀 옥사이드(rGO, reduced graphene oxide) 27
5. 그래핀계 복합체 여과막 29
제2절 셀룰로오스 31
1. 나노셀룰로오스 33
2. 셀룰로오스계 유수 분리막 36
제3절 유수분리 기술 38
1. 습윤 재료의 이론 40
제4절 유수분리용 그래핀_셀룰로오스 복합체 제조 42
1. 그래핀과 셀룰로오스 간의 계면 상호작용 42
2. 나노셀룰로오스에 의한 그래핀 분산 44
제3장 실험 46
제1절 시약 및 재료 46
제2절 실험 방법 46
1. GO (Graphene Oxide)제조 46
2. CNF(Cellulose nano fiber) membrane 제조 47
3. CNF_GO membrane 제조 47
4. CNF_rGO membrane 제조 47
제3절 분리막 특성 분석 50
1. 분리막의 표면 분석 50
2. 분리막의 구조 및 특성 분석 50
3. 분리막의 결정성 분석 50
4. 분리막의 열적 안정성 분석 50
5. 분리막의 표면 습윤성 분석 51
6. 분리막의 유수분리 성능 분석 51
제4장 결과 52
제1절 분리막의 표면분석 52
제2절 분리막의 구조 및 특성 분석 56
제3절 분리막의 결정성 분석 64
제4절 분리막의 열적 안정성 분석 66
제5절 분리막의 표면 습윤성 분석 68
제6절 분리막의 유수분리 성능 분석 71
제5장 결론 74
참고문헌 76
국문요약 88
Table 1. Properties comparison between plant nanocellulose and bacterial cellulose 35
Table 2. Particle size of GO bonded to composite membrane 55
Table 3. FTIR absorption band for functional group of membrane 63
Figure 1. Various carbon materials: a) graphene b) graphite c) carbon nanotube d) fullerene 19
Figure 2. a) Graphene structure of single two-dimensional hexagonal sheet of carbon atoms b) Schematic of the in-plane σ bonds and the π orbitals perpendicular to the plane of the... 20
Figure 3. Various top-down processes for production of graphene 21
Figure 4. Scheme showing the chemical route to the synthesis of aqueous graphene dispersions 23
Figure 5. Chemical structure of graphene and graphene oxide 25
Figure 6. Schematic illustration of graphene oxide synthesis by chemical oxidation using brodie's, Staudenmaier's and Hummer's methods 26
Figure 7. Synthesized routes of graphite to graphene oxide and reduced graphene oxide. 28
Figure 8. Selective separation of an oil/water mixture using a graphene-coated membrane 30
Figure 9. A schematic showing the transition of plant fibers to cellulose nanoparticles. 32
Figure 10. (a) Chemical structure of cellulose, (b) morphology of cellulose nanocrystals, cellulose nanofibers and bacterial nanocellulose 34
Figure 11. Principal oil/water separation techniques 39
Figure 12. Diagrammatic sketches of (a) contact angle, (b) Wenzel model, and (c) Cassie−Boxter model 41
Figure 13. a) Schematic illustration of the hydrogen bonding (red rows) of regenerated GO nanosheets and NCs molecular chains(Tang et al., 2012) b) Model of the interfacial... 42
Figure 14. a) b) Interfacial interaction categories in graphene-based nanocomposites, including non-covalent and covalent bonding 43
Figure 15. a) Schematic view of two-dimensional materials disperses by Nanocellulose. b) Schematic view of hydrophilic-hydrophobic crystalline face of cellulose. 45
Figure 16. Preparation of Cellulose nano fiber (CNF) 48
Figure 17. Schematic view of preparation and fabrication of CNF_rGO hybrid film 49
Figure 18. SEM image of membrane a) CNF, b) CNF_GO 53
Figure 19. SEM image of membrane a) CNF, b) CNF_GO_pH2, c) CNF_GO_pH5, d)CNF_GO_pH7, e) CNF_GO_pH9, f) CNF_GO_pH11 54
Figure 20. Alkali treatment reaction of Cellulose nano fiber with NaOH 58
Figure 21. Preparation procedures for the preparation of CNF_GO composite 59
Figure 22. FTIR spectra of CNF, GO and CNF_GO 60
Figure 23. FTIR spectra of CNF_GO according to pH 61
Figure 24. FTIR spectra of membrane CNF_rGO, CNF_GO_pH2 and GO 62
Figure 25. XRD patterns for GO, CNF, and CNF_GO 65
Figure 26. TGA curves of CNF_GO according to pH 67
Figure 27. Contact angle for water: a) CNF_GO_pH2, b) CNF_rGO 69
Figure 28. Contact angle of the membrane prepared by pH with respect to water 70
Figure 29. Contact angle of the membrane prepared by pH with respect to oil 70
Figure 30. Light oil/water separation 72
Figure 31. Heavy oil/water separation 72
Figure 32. Oil/water separation efficiency of membrane 73