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Preparation of Polymeric Nanofiber Composites Using Simultaneous Electrospinning/Electrospraying and Their Application to Protective Materials

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dc.contributor.advisor곽승엽-
dc.contributor.author류수열-
dc.date.accessioned2017-07-13T05:51:41Z-
dc.date.available2017-07-13T05:51:41Z-
dc.date.issued2016-08-
dc.identifier.other000000136124-
dc.identifier.urihttps://hdl.handle.net/10371/118080-
dc.description학위논문 (박사)-- 서울대학교 대학원 : 재료공학부, 2016. 8. 곽승엽.-
dc.description.abstractNanomaterials demonstrate interesting physical and chemical properties compared with conventional materials. Various types of new materials, such as nanoparticle, nanorod, nanosphere and nanofiber, have been investigated. The creation of new functional nanomaterials contributes significantly to the innovation of nanoscience and nanotechnologies. Among them, electrospun nanofibers have been attracting the attention of highly functional materials due to their enhanced properties, such as high surface to volume ratio, very high porosity compared to other conventional fibers. So, nanofibers have been studied for various applications in fields of filtration, tissue engineering, sensor, protective material, electronic and photonic material and drug delivery. In this study, the polymeric nanofiber composites were developed using simultaneous electrospinning/electrospraying, then applied to protective materials. In chapter 2, two types of electrospun polyamide nanofiber composites in which Ag-TiO2 was located either in the interior or on the surface of the nanofiber using electrospinning and simultaneous electrospinning/electrospray (SEE) process, respectively. The performance of the obtained Ag-TiO2-embedded nanofiber composite (interior located Ag-TiO2: AT-in-NF) and Ag-TiO2-decorated nanofiber composite (surface located Ag-TiO2: AT-sur-NF) was compared by evaluating the decolorization of methylene blue (MB) stain and their antimicrobial ability. It was concluded that the positioning of nanomaterial additives is a crucial factor in the enhanced performance of such nanofiber composites, and provide a guide for designing and optimizing nanofiber composites with superior catalytic activities. In chapter 3, a potential application of nanofibrous composite materials impregnated the MgO and POM adsorbents was exhibited as an inner layer for the permeable protective clothing against CWA. The nanofiber composites, which were consisted of both polyamide nanofiber and adsorbents (MgO and POM), were prepared using the SEE process. The nanofiber composites were compared to neat polyamide nanofiber mat by evaluating the permeability of air, moisture and protectability against gas chemical warfare simulants. It was suggested that the high possibility of the application of the nanofiber composites to the inner layer of permeable protective clothing. In chapter 4, it was reported that electrospun meta-aramid nanofibers with enhanced chemical stability and mechanical property using sequential post-treatment for removal of salt in the nanofiber and regeneration of crystalline structure. The aligned meta-aramid nanofibers with LiCl salt was prepared using electrospinning apparatus with drum-collector. The washing and heating sequential post-treated nanofiber mats showed improved chemicals stability. Furthermore, in order to estimate the possibility of their application to an outer layer for permeable protective clothing having the repellency against liquid chemical warfare simulants, the surface of meta-aramid nanofibers was modified via treatment using water and oil repellent. In chapter 5, lightweight nanofibrous assemblies with high protection ability against chemical warfare agents (CWAs) were developed using laminated outer and inner layers based on aromatic and aliphatic polyamide nanofiber composites with CWA adsorbents magnesium oxide and polyoxometalate. Thickness, weight density (weight per area), cool/warm feeling and air/moisture permeability of the assembly were compared with the permeable protective clothing of Korea Army as a reference. The thickness and weight density were variated according to the number of stacking, and finally, the lightweight assemblies with high protectability against CWA can be developed. The assembly surpassed the reference in the cool feeling property, and provided good resistance to the penetration of chemical warfare agents in gas form, while still allowing significant water vapor transmission to promote evaporate cooling of the body. The development of the assembly suggests new approach to improving performance of a permeable protective materials, and provides a guide for designing and optimizing the permeable protective clothing.-
dc.description.tableofcontentsChapter 1 Introduction 1
1.1 Nanofiber 1
1.2 Electrospinning Process 9
1.2.1 Polymer solution parameter (materials variables) 9
1.2.2 Processing parameter (processing variables) 13
1.2.3 Example: electrospinning condition of polyamide 66 17
1.3 Application of Electrospun Nanofibers 21
1.3.1 Tissue scaffolds 21
1.3.2 Filtration 24
1.3.3 Protective clothing materials 25
1.3.4 Energy generation 26
1.3.5 Reinforcement materials 27
1.3.6 Cosmetics 28
1.4 Summary 29
1.5 Research Objectives 30

Chapter 2 Ag-TiO2 Decorated Nylon 66 Nanofibrous Protective Materials with both Self-Cleaning and Antimicrobial Activities 37
2.1 Introduction 37
2.2 Experiments 40
2.2.1 Preparation and characterization of Ag-TiO2 40
2.2.2 Preparation and characterization of Ag-TiO2-embedded and decorated nanofiber composites 41
2.3 Results and Discussion 46
2.3.1 Preparation and characterization of Ag-TiO2 46
2.3.2 Characteristics of Ag-TiO2-embedded and decorated nanofiber composites 55
2.3.3 Photocatalytic and antimicrobial activities of Ag-TiO2-embedded and decorated nanofiber composites 60
2.4 Summary 67

Chapter 3 Nanofibrous Inner Layer of Chemical Warfare Protective Materials with Adsorptivity of Chemical Warfare Agents 71
3.1 Introduction 71
3.2 Experiments 76
3.2.1 Adsorptivity of chemical warfare agent simulants on MgO and POM particles 76
3.2.2 Nanofibrous inner layer for adsorptive protection against chemical warfare simulants 77
3.3 Results and Discussion 84
3.3.1 Adsorptivity of chemical warfare agent simulants on MgO and POM particles 84
3.3.2 Nanofibrous inner layer for adsorptive protection against chemical warfare simulants 87
3.4 Summary 100

Chapter 4 Nanofibrous Outer Layer of Chemical Warfare Protective Materials with Repellency of Chemical Warfare Agents 103
4.1 Introduction 103
4.2 Experiments 108
4.2.1 Materials 108
4.2.2 Optimization of preparation condition for meta-aramid nanofiber mat with improved chemical stability and mechanical property 109
4.2.3 Nanofibrous outer layer for repellent protection against chemical warfare agent simulants 113
4.3 Results and Discussion 118
4.3.1 Optimization of preparation conditions for meta-aramid nanofiber mat with improved chemical stability and mechanical property 118
4.3.2 Nanofibrous outer layer for repellent protection against chemical warfare agent simulants 135
4.4 Summary 144

Chapter 5 Multilayer Assemblies of Nanofiber Composites as Permeable Protective Materials against Chemical Warfare Agents 147
5.1 Introduction 147
5.2 Experiments 151
5.2.1 Assembly of the outer and inner layers for nanofibrous protective materials against chemical warfare simulants 151
5.2.2 Characterization of the assembly of the outer and inner layers 153
5.3 Results and Discussion 156
5.3.1 Assembly of the outer and inner layers for nanofibrous protective materials against chemical warfare simulants 156
5.3.2 Characterization of the assembly of the outer and inner layers 157
5.4 Summary 172

References 173

Conclusion 175

Korean Abstract 177

List of papers, patents and symposiums 180
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dc.formatapplication/pdf-
dc.format.extent8184586 bytes-
dc.format.mediumapplication/pdf-
dc.language.isoen-
dc.publisher서울대학교 대학원-
dc.subjectNanofiber-
dc.subjectComposite-
dc.subjectElectrospinning-
dc.subjectElectrospraying-
dc.subjectPolyamide-
dc.subjectmeta-Aramid-
dc.subjectAmphiphobicity-
dc.subjectProtective material-
dc.subjectChemical warfare agent-
dc.subjectChemical warfare simulant-
dc.subject.ddc620-
dc.titlePreparation of Polymeric Nanofiber Composites Using Simultaneous Electrospinning/Electrospraying and Their Application to Protective Materials-
dc.typeThesis-
dc.description.degreeDoctor-
dc.citation.pagesxix, 185-
dc.contributor.affiliation공과대학 재료공학부-
dc.date.awarded2016-08-
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College of Engineering/Engineering Practice School (공과대학/대학원)Dept. of Materials Science and Engineering (재료공학부)Theses (Ph.D. / Sc.D._재료공학부)
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