Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002. / Includes bibliographical references. Also available in electronic version. Access restricted to campus users.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1966. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--Columbia University, 1928. / Vita. Bibliography: p. 31.

Thesis (Ph. D.)--University of Missouri, 1935. / Vita. By T.G. Day and W.T. Schrenk. Published also as part 2 of "The quantitative determination of lead by the electrolytic deposition of lead dioxide ... By Thomas Gordon Day, Phillip Hall Delano and W.T. Schrenk." Rolla, Mo., 1935. eContent provider-neutral record in process. Description based on print version record. Bibliography: p. 62-68.

Thesis (Ph. D.)--University of Pennsylvania, 1904. / Includes bibliographical references.

Thesis (Ph. D.)--State University of New York at Binghamton, Department of Chemistry. / Includes bibliographical references.

The concept of "aggregation-induced emission" (AIE) effect has induced a great deal of attention these days. Now, exploration of new AIE-active molecular system and multiple high technique applications for AIE materials are the two research hotspots. Cyanostilbene, as a classical structural unit in photoelectric functional materials, also exhibited this unique luminescence behavior. The research background was illustrated in Chapter 1, which mainly introduced the development of this subject. In this project, Chapter 2 and Chapter 3 presented two classes of functionalized AIE-active molecules based on cyanostilbene moiety, and their applications were investigated, while Chapter 4 demonstrated a series of donor-acceptor (D-A) molecules with highly emissive unit, and their photophysical properties were studied.;In Chapter 2, four different donor-substituted cyanostilbene-based dipyrrins were synthesized and characterized. The investigation of photophysical properties confirms that these molecules are AIE-active, which should be attributed to the cyanostilbene moiety. The introduction of different donor groups showed little impact on their luminescence. Furthermore, the emission properties of these molecules were found to be sensitive to Zn2+, that is, addition of Zn2+ enormously enhanced its fluorescence in THF. The titration experiments proved they showed good selectivity and sensitivity for Zn2+ detection with relatively low limit of detection. Job's curve and spectral studies of their corresponding zinc complex indicated that the ratio for dipyrrins and Zn2+ is 2:1, which suggested the formation of zinc complex by chelation-enhanced fluorescence (CHEF) effect should be the reason of the enhanced fluorescence. By combining dipyrrin with typical AIE-active moiety tetraphenylethylene (TPE), an AIE-active TPE-based dipyrrin was prepared. The studies of its fluorogenic Zn2+ detection confirmed that the CHEF effect together with AIE effect are responsible for the intense fluorescence, indicating the potential application as a Zn2+ detector in aqueous media.;In Chapter 3, the cyanostilbene backbone was functionalized with a terpyridine unit to construct four terpyridine-based cyanostilbene molecules with different donor substitutents. The investigation of their photophysical properties confirms that they are AIEE-active. With the effect of different electron-donating groups, their solid-state fluorescence color was adjusted from blue to orange-red successfully. According to the calculation results of their frontier molecular orbitals, terpyridine has little impacts on their luminescence, but would influence their solid-state emission obviously owing to its large steric hindrance. This class of molecules displayed higher luminescence efficiency in solid state than in their dissolved state. The twisted molecular conformation in single crystal, which effectively avoids close π-π stacking, was assumed to be responsible for the high luminescence efficiency in solid state. This kind of molecules show distinct switched fluorescence by stimuli of acid/base vapors, and this phenomenon derives from the protonation effect of nitrogen atoms in the terpyridine unit. Moreover, three of these molecules exhibit good electroluminescence properties. Especially, the crystal of non-donor substituted molecule show amplified spontaneous emission (ASE) properties, indicating this blue-emissive material can be used in multiple areas such as chemical sensor, organic light emitting diodes (OLEDs) and organic laser media.

Recently, point-of-care diagnostics has gained great attention because it can improve patient’s quality of life. Electrochemical diagnostic systems are promising because of their miniaturizability and low-cost. However, fabrication of such devices requires special skills as well as expensive equipment and supplies. This thesis is based on a research project aimed at fabricating electrochemical sensors combing wax printing and inkjet printing or wax printing and hand painting. The electrochemical sensors can be used for measuring different kinds of electrochemical analytes like dopamine, uric acid by electrochemical methods like amperometry, which can show great calibration curve. The LOD of dopamine, uric acid, ascorbic acid, Nile Blue, hydrogen peroxide and ferrocene is 0.015 µM, 7.3 µM, 30 µM, 1.3 µM, 8 nM and 30 µM, respectively. Further, we can modify the electrochemical sensor by using multiwall carbon nanotube in order to improve the sensitivity of the electrochemical sensors. This modified electrochemical sensor can also be used as immunoassay by sandwich format ELISA for detecting carcinoembryonic antigen (CEA), which has been designated as a reliable biomarker for several types of cancers. We found that the CNT modified hand-painting device can detect CEA down to 0.6 ng/mL, which is three times lower than the cut-off value of diagnosis, i.e. 5 ng/mL in blood.

The modification of electrodes is always an important task in electrochemical detection of electroactive and biological molecules. Chemically modified electrodes can offer improved selectivity and sensitivity for the target analyte, which greatly enhance the electrode performance. Various materials such as conducting polymers, metal nanoparticles and carbon nanomaterials have been exploited and widely used for the modification of electrodes. Electrochemical or spontaneous deposition, electrostatic adsorption, layer-by-layer self assembly and covalent binding have also been developed for electrode modification and offer improved performance. Both Prussian blue (PB) and toluidine blue O (TBO) are excellent redox mediators and very popular in electrode modification. PB has shown strong catalytic property for the reduction of hydrogen peroxide, but the application in biosensor fabrication is limited for its instability at neutral pH. Graphene, as a single-atom-thick carbon material, is considered an ideal platform for designing composite nanomaterials for high-performance electrochemical or electrocatalytic devices. The combination of PB with reduced graphene oxide (RGO) and poly(toluidine blue O) (PTBO) will greatly improve the stability of PB. An amperometric biosensor based on glassy carbon (GC) electrode modified with reduced graphene oxide, PB and poly(toluidine blue O) was developed. Experimental results showed that the GC/RGO/PB/PTBO modified electrode offered an excellent electrocatalytic activity toward the reduction of hydrogen peroxide due to the possible synergistic effects of the PB-PTBO composite material. After codeposition of glucose oxidase (GOD) and chitosan (CHIT) coating, the resulting GC/RGO/PB/ PTBO/CHIT-GOD electrode exhibited excellent response to glucose with a sensitivity of 59 mA M1 cm2, a low detection limit of 8.4 μM and a linear range from 0.02 to 1.09 mM at a detection potential of +0.2 V vs. Ag.

In order to address ground and industrial water pollution, the University of Manchester has developed a novel and economic water treatment technology called the Arvia® process. This technology is being commercialized through a spin-out company, Arvia Technology Ltd. This process consists of adsorption and electrochemical regeneration in a single unit and can be carried out in batch or continuous modes where both operations can run simultaneously. This process has been successfully demonstrated for the removal and destruction of a number of organic contaminants using a graphite based adsorbent known as Nyex®1000. Nyex®1000 is an intercalation compound prepared from Chinese natural large fake graphite. This adsorbent has been found to be capable of fast adsorption and quick electrochemical regeneration in minutes due to its non-porous surface and high electrical conductivity. However, Nyex®1000 has a small adsorptive capacity for a number of organic pollutants and there is thus a need to develop new adsorbents with the aim of achieving high adsorptive capacity with maintaining good electrical conductivity. In this context, three routes for the development of adsorbents were selected, adsorbents developed through electrochemical intercalation, adsorbent developed through thermal and mechanical treatment of GIC-bisulphate and adsorbents developed through the formulation of composite materials. In order to strengthen the contributing effect of surface treatment, all raw graphite materials and developed adsorbents were characterized using Boehm titration, X-ray EDS, zeta potential, powder XRD, SEM, BET surface area, pore volume, particle size and bulk density techniques. These adsorbents were tested for the removal of a number of different target organic pollutants such as acid violet 17, mercaptans, phenol and humic acid using the Arvia® process. The performance of the developed materials was compared with the current adsorbent used in the Arvia® process i.e. Nyex®1000. A range of graphite types (synthetic graphite, Chinese natural large fake gra- phite, Madagascan medium fake graphite, natural vein graphite and recycled Abstract 27 vein graphite) were tested for the removal of acid violet 17 before and after electrochemical treatment in order to investigate the selection of the graphite types for the Arvia® process. The electrochemical surface treatment improved the adsorptive capacity by a factor of two for most of the graphite types tested and changed the surface of the graphite from hydrophobic to hydrophilic. Results obtained through surface characterization using Boehm titration, X-ray (EDS) elemental analysis and zeta potential measurements revealed a significant increase in oxygen containing surface functional groups on the surface of CNLFG in consequence of electrochemical surface treatment. The second type of adsorbent was developed through thermal and mechanical treatment of GIC bisulphate. It was tested for the removal of acid violet 17, mercaptans (ethane thiol & methyl propane thiol), phenol and humic acid using the Arvia® process. This material had twice the electrical conductivity of Nyex® 1000 and improved the adsorptive capacity by a factor of three for acid violet 17, approximately seven to eight for ethane thiol and methyl propane thiol, seven for phenol and two for humic acid. Starting and developed adsorbent materials were characterized using above mentioned techniques. The third type of adsorbent materials, three composite adsorbents were developed using high shear (wet) and compaction (dry) granulation methods. The composite adsorbent made through high shear wet granulation was found to have poor mechanical strength. The second and third composite adsorbents were developed through dry compaction granulation using carbon black, synthetic graphite and exfoliated graphite as raw materials. These adsorbents delivered improved adsorptive capacity for acid violet 17 by a factor of 100 and 9 respectively. Electrochemical regeneration efficiencies of around 100 % were obtained for these adsorbent materials. However, electrochemical parameters required to achieve 100 % regeneration, such as current density and regeneration time were found to vary depending on the adsorptive capacity of each adsorbent material for a particular polluting agent.