Cleaning of impurities from cotton textiles using compressed liquid CO₂ combined with co-solvents

국문 초록 (Abstract)

액체 이산화탄소(L-CO₂)는 무독성, 불연성 및 환경 친화적 특성으로 인해 드라 이클리닝에서 기존 유기 용매의 안전하고 지속 가능한 대안으로 부상했습니다. 그 러나 L-CO₂로 직물에서 제거 가능한 화합물은 알려지지 않았습니다. 본 연구에서는 L-CO₂ 드라이클리닝의 온도, 유속 및 보조용매를 최적화하고, 가스 크로마토그래피 비행시간형 질량분석법(GC-TOF/MS)을 활용하여 이 방법으로 제거 가능한 화합물을 확인하였다. 최적의 보조용매 혼합물은 이소프로판올(IPA)/물 7:3(v/v) 비율이었다. 본 L-CO₂+IPA/H₂O 드라이클리닝 방법은 콜레스테롤, 지방산, 질소 함유 화합물, 당 류 및 당 유도체 등 다양한 물질 제거에 높은 효능을 나타냈다. 특히 오염된 직물 에서 콜레스테롤이 100% 제거되었다.

다국어 초록 (Multilingual Abstract)

Liquid CO2 (L-CO2) has emerged as a safe and sustainable alternative to conventional organic solvents in dry cleaning owing to its non-toxic, non-flammable, and environmentally friendly nature. However, the compounds that can be removed from the fabrics by L-CO₂ are unknown. In this study, it was optimized the temperature, flow rate, and co-solvent for L-CO₂ dry cleaning and identified the compounds that can be removed by this method using gas chromatography–time-of-flight mass spectrometry. A 7:3 (v/v) isopropanol(IPA)/water mixture was the optimal co-solvent mixture. L-CO2+IPA/H2O dry cleaning method exhibited high efficacy in removing a diverse range of substances, such as cholesterols, fatty acids, N-compounds, sugars, and sugar derivatives. In particular, 100% of the cholesterols were removed from the stained fabric.

목차 (Table of Contents)

• Chapter 1. Introduction 1
• 1.1 Research Backgrounds 1
• 1.2 Thesis Objectives 3
• Chapter 2. Materials and methods 5
• 2.1 Materials 5
• 2.2 Textile cleaning apparatus 6
• 2.3 Textile cleaning experiments 8
• 2.3.1 Cleaning with organic solvents 8
• 2.3.2 L-CO₂ cleaning with and without an organic co-solvent 8
• 2.4 Characterization 9
• 2.4.1 Color analysis 9
• 2.4.2 GC–TOF/MS analysis 10
• 2.4.3 Chemical functional groups analysis using attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy 11
• 2.4.4 Fabric surface analysis using scanning electron microscopy (SEM) 11
• Chapter 3. Results and discussion 12
• 3.1 Co-solvent cleaning tests to find the appropriate dry cleaning solvent mixture 12
• 3.2 Effects of flow rate and temperature of L-CO₂ on stain removal 14
• 3.3 Dry cleaning with the co-solvent/L-CO₂ mixture 16
• 3.4 Morphology of the fabrics before and after L-CO₂ cleaning 20
• 3.5 ATR-FTIR analysis 22
• 3.6 Identification of the contaminants removed by L-CO₂ cleaning 25
• Chapter 4. Conclusion 31