Title Page
Contents
Abstract 9
Chapter 1. General Introductions 19
1.1. Polymeric Chemosensors 19
1.2. Thin Polymeric Films 19
1.3. Small Biomolecule Responsive Chemosensors 20
1.4. Hydrogel Chemosensors 21
Chapter 2. Advancements in water-soluble polymeric chemosensors for efficient analyte screening 22
2.1. Introduction 22
2.2. Experimental Section 24
2.2.1. Materials 24
2.2.2. Instrumentation 24
2.2.3. Synthesis 24
2.3. Results and Discussion 30
2.4. Conclusions 42
2.5. References 42
Chapter 3. Thin polymeric film engineering for real-time colorimetric detection 44
3.1. Introduction 44
3.2. Experimental Section 46
3.2.1. Materials 46
3.2.2. Instrumentation 46
3.2.3. Synthesis 46
3.3. Results and Discussion 49
3.4. Conclusions 59
3.5. References 60
Chapter 4. Smart polymeric micelles: small molecule-responsive design for analyte screening and drug delivery applications 62
4.1. Introduction 62
4.2. Experimental 64
4.2.1. Materials 64
4.2.2. Instrumentation 65
4.2.3. Synthesis 65
4.3. Results and Discussion 70
4.4. Conclusions 83
4.5. References 84
Chapter 5. Developing thermo-responsive polymers: synthesis to innovation 86
5.1. Introduction 86
5.2. Experimental 87
5.2.1. Materials 87
5.2.2. Instrumentation 88
5.2.3. Synthesis 88
5.2.4. Preparation of probe and analyte stock solution for fluorometric detection study 89
5.2.5. Estimation of limit of detection (LOD) 90
5.2.6. Determination of the quantum yield of P4 90
5.2.7. Phase diagram measurement 90
5.2.8. Quantitative separation of Hg(II) and reusability experiment 90
5.3. Results and Discussion 91
5.4. Conclusions 97
5.5. References 97
Chapter 6. Heterogeneous platform for precious metal recovery from scraps at highest purity 99
6.1. Introduction 99
6.2. Experimental 100
6.2.1. Chemicals and materials 100
6.2.2. Characterization 101
6.2.3. Synthesis 101
6.2.4. Fabrication of F1 103
6.2.5. Fabrication of hydrogel, HG 103
6.2.6. Preparation of probe and analyte stock solutions for the Au/Pt sensing studies 103
6.2.7. LOD calculation 103
6.2.8. Binding constant calculation 104
6.2.9. HG swelling studies 104
6.2.10. Au removal studies by F1 105
6.2.11. Pt extraction and selectivity studies from spiked solution 105
6.2.12. Removal rate determination 105
6.2.13. Removal capacity of F1 determination 105
6.2.14. Pt extraction efficiency under different pH conditions 105
6.2.15. Au extraction from e-waste 106
6.2.16. Au recovery from e-waste 106
6.2.17. Reusability of HG 106
6.2.18. Spent auto catalyst leaching 106
6.2.19. Pt recovery from spent auto catalyst by HG 106
6.2.20. Pt uptake (q) calculation 107
6.3. Results and Discussion 107
6.4. Conclusions 120
6.5. References 121
Curriculum Vitae 125
List of Publications 126
Chapter 2 12
Figure 2.1. (a) 1H NMR spectra of P1 in CDCl3. (b) GPC trace of P1. 30
Figure 2.2. (a) Fluorescence emission spectra of P1 at different pH values, with λexc of 485 nm. (b) Fluorescence intensity versus pH plot. (c) Photograph of P1 solution at different pH values taken under...[이미지참조] 31
Figure 2.3. (a) Illustration of fluorescence quenching in 3 due to PET inhibition associated with 3-H+ formation by protonation, as obtained at the B3LYP/6-311+G (d,p) level of theory. (b) Photographs of... 32
Figure 2.4. (a) Determination of cytotoxicity of P1 via MTT assay. The IC50 value of P1 was 250 μg/mL at the significance level of *P<0.001. (b) DIC, fluorescence, and merged fluorescence-DIC... 33
Figure 2.5. 1H NMR spectra of (a) p(DMA-co-BODIPYCHO) and (b) P2. Asterisk indicates solvent resonance. 34
Figure 2.6. (a) UV-vis absorption and (b) emission spectra of P2 (2.5 × 10-4 M of aldoxime units) in the presence of various NaOCl concentrations (0-10 μM) in DI water (pH=7.4). Insets (a) and (b):... 35
Figure 2.7. Photographs of paper strips coated with P2 (1 mM, DI water) after coating with various ROS and RNS species (1 μM stock solution). Images (a) were taken under normal daylight, whereas... 37
Figure 2.8. (a) 1H NMR of Azo-aldehyde and Azo-1 in CDCl3. (b) UV-vis absorption spectra of Azo- 1 (1.0 × 10-5 M) with varying concentrations of CN- in THF. (c) The LOD of Azo-1 for detecting CN-... 39
Figure 2.9. (a) 1H NMR of p(DMA-co-azo-aldehyde) and P3 in CDCl3. (b) Change in UV-vis spectra of P3 in water at pH 7.4 with various concentrations of CN-. (c) The LOD of P3 for detecting CN- in... 40
Figure 2.10. (a) Schematic depiction of cyanogenic food sample preparation. (b) Photograph of P3 test strips demonstrating the association between tracing CN- in various cyanogenic food samples with time... 41
Chapter 3 13
Figure 3.1. (a) Syntheses of M1 and relevant probable CN⁻-sensing mechanism. Inset: chemical structure of M1 and this compound's salient features. (b) Change in the UV-Vis absorption spectra of a... 50
Figure 3.2. (a) 1H NMR spectrum of P1 in CDCl3. (b) UV-vis absorption spectra of a 2.0 × 10⁻⁵ M solution of P1 in aqueous-HEPES buffer solution at pH 7.4 in the presence of various concentrations... 51
Figure 3.3. (a) P1 film (F1) preparation procedure and plausible mechanism for the immobilization of P1 onto a quartz glass slide brought about by exposure to UV light (λ=365 nm). MeOH, methanol. (b)... 52
Figure 3.4. (a) Synthesis and illustration of hydrazine detection in THF of small molecular probe M2. (b) Reaction time profile of M2 (1.0 × 10-5 M in THF) in the presence of 0.10 mM hydrazine. (c) UV-... 54
Figure 3.5. (a) 1H NMR spectra of p(DMA-co-FPDEA-co-BPAm) and P2 in CDCl3. (b) Change in UV-vis spectra of P2 (25 μM concentration of azo-dicyano units, in THF) with varying hydrazine... 55
Figure 3.6. (a) Illustration of vapor-phase hydrazine detection by F2 film. (b) Schematic illustration of the F2 preparation procedure. (c) Photograph and (d) change in the UV-vis spectrum of F2 upon... 57
Figure 3.7. (a) Schematic illustration of a soil test using P2 and F2 in THF/H2O (50:50). (b) Schematic illustration of a water test using F2. Relative △λmax plots of hydrazine detection in different soils (sand... 58
Chapter 4 14
Figure 4.1. 1H NMR of (a) Azo-OH, (b) Azo-CTA, (c) PBA (d) P(PBA). 70
Figure 4.2. (a) Overlaid GPC traces of PPBA macroCTA and P1, (b) ¹H NMR spectrum of P1. 70
Figure 4.3. (a) The fluorescence emission spectra of pyrene as a probe of block copolymer, P1 concentration in water, (b) Fluorescence intensity ratio of I₃₇₁/I₃₉₁ from pyrene emission spectra vs the... 72
Figure 4.4. UV-vis absorption spectra of 0.05 wt. % of a micellar solution of P1 up to the addition of (a) 2 mM and (b) 160 mM of cysteine; Inset: LOD of 0.05 wt. % micellar solution of P1 at pH 7.4... 73
Figure 4.5. (a) Changes in UV-vis spectra of P1 micellar solution (0.05 wt.%) with the variation of glucose concentration, keeping the cysteine concentration at 20 mM. (b) Photograph showing the... 75
Figure 4.6. (a) Schematic representation of M1 synthesis and detection mechanism. (b) ¹H NMR spectrum of M1 in CDCl3. (c) UV-vis titration of M1 (1.5 Χ 10⁻⁵ M) in DMSO. (d) LOD calculation... 77
Figure 4.7. (a) Schematic synthesis of the model Passerini monomer M2. (b) UV-vis titration of M2 (Inset: photographs of M2 without and with 40-µM H₂S under visible light). (c) The corresponding... 77
Figure 4.8. (a) Schematic synthesis of the H₂S-specific amphiphilic polymer P2. (b) GPC traces of PEG and P2, showing the average molecular weight (Mn) and polydispersity index (Đ). (c) The plot of... 79
Figure 4.9. (a) The time-dependent hydrodynamic size distribution of P2 (0.01 wt.%) before and after H₂S addition. (b) Representative AFM phase images of P2 (0.005 wt.%) spin-coated onto mica before... 80
Figure 4.10. (a) A schematic of the detection process by P2. (b) UV-vis absorption titration of 0.005- wt.% P2 micellar solution with incremental addition of H₂S (inset: photographic images of the micellar... 81
Figure 4.11. (a) A schematic of the hydrophobic drug loading and release by P2 in the presence of H₂S. (b) Fluorescence spectra showing the detection and sustained release of the rhodamine from P2 with a... 82
Chapter 5 16
Figure 5.1. ¹H NMR spectra of (a) P1, (b)P2, (c)P3, and (d) P4 in CDCl₃. Asterisk (*) indicates solvent resonance. 91
Figure 5.2. (a) Fluorescence emission spectra of P4 (0.028 mg/mL, assuming 20 µM BODIPY units) upon the gradual addition of Hg(II) in water. Excitation wavelength: 485 nm. Inset: Photographs of P4... 92
Figure 5.3. (a) Fluorescence emission intensity of P4 at 544 nm over time after the addition of 20 µM Hg(II). (b)Selectivity bar diagram of fluorescence response of P4 in the presence of various competitive... 93
Figure 5.4. Thermal phase transition diagram of (a) P1 and (b) mixtures of P1 and P4 at different weight ratios as a function of polymer concentration in water. (c) A schematic representation of temperature-... 94
Figure 5.5. Pictorial representation of the efficient separation of Hg(II) in the presence of other competitive metal cations by blend-B (P1:P4=70:30) and its recycling process facilitated by HgS... 95
Figure 5.6. (a) Selectivity bar diagram representing the removal efficiency of Hg(II) by blend-B (P1:P4=70:30, overall, 13 wt.% in water) in the presence of other competitive metal cations after 1st cycle....[이미지참조] 96
Chapter 6 16
Figure 6.1. (a) A schematic diagram showing the synthesis and application of P1 to detect Au(III) in water; (b) the ¹H NMR spectra of P1 in CDCl₃; (c) the changes in the UV-vis spectra of P1 (25 µM... 108
Figure 6.2. (a) Schematic representation of the immobilization of P1 onto a quartz glass slide by exposure to UV light (λ=365 nm) to form F1, followed by Au(III) detection and removal by selective... 109
Figure 6.3. (a) Flow sheet of the collection of e-waste sources and the preparation of different sets of e- waste solutions and illustrating the potential of F1 to show the presence or absence of Au(III) by... 110
Figure 6.4. (a) A flow chart illustrating the stepwise potential of F1 to selectively remove and recover Au(III) from e-waste set 1 by selective binding and the reusability of F1 by the ligand exchange with... 112
Figure 6.5. (a) Free radical polymerization for the synthesis of p(DMA-co-Im), followed by post- polymerization modification to yield p(DMA-co-M1), P2; (b) GPC traces of p(DMA-co-Im) and P2. 113
Figure 6.6. (a) Primitive depiction of P2 detecting Pt(II) in water by fluorescence quenching; (b) absorption spectra of P2 (approximately 82 µM of imidazole units along the polymer chain) with... 114
Figure 6.7. (a) Selectivity bar diagram of fluorescence responses of P2 (approximately 82 µM of imidazole units along the polymer chain) in water with various metal ions (1.25-mM concentration) at... 115
Figure 6.8. (a) Photographic illustration of photopolymerization of DMA, Vlm, and MBA with HMP photoinitiator under UV lamp to produce hydrogel, followed by modification with 9-... 117
Figure 6.9. (a) Schematic portrayal of the simultaneous detection and adsorption of Pt(II) from mixtures of competitive metal ions by selective coordination by HG. (b) Photographs of HG taken under a 365-... 118
Figure 6.10. (a) Flow sheet depicting the preparation of real sample; spent auto catalyst from automobile by collection, dismantling, grinding, and finally leaching in HCl:H2O2. (b) Schematic representation... 120
Scheme 2.1. (a) Synthesis of P1 showing the protonation-driven turn-on fluorescence mechanism. PET: photo-induced electron transfer. (b) Synthetic scheme for preparing water-soluble aldoxime-... 24
Scheme 3.1. (a) Synthetic route of P1 synthesis and relevant probable CN⁻-sensing mechanism. (b) Synthesis and illustration of hydrazine detection in THF of polymeric probe P2. 46
Scheme 4.1. (a) Overall schematic representation to picture the colorimetric detection of cysteine and glucose and their dependence on each other. (b) A schematic of the self-assembly and model drug... 64
Scheme 5.1. Synthetic pathway for the preparation of P4 and its reversible Hg(II) sensing mechanism. 87