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Cytoskeleton is a structure that enables cells to maintain their shape and internal organization. The proper functions of cytoskeleton depend crucially on the mechanical responses and properties of its component filaments (e.g., microtubules and actin filaments). Thus, an in-depth understanding of cytoskeletal filaments mechanics is essential in revealing how cells fulfil their biological functions via cytoskeleton, stimulating the innovative idea in designing biomimetic structure or materials and facilitating to develop novel techniques in disease diagnosis and treatment. This thesis thus focuses on studying the inherent and environmental factors that determine the nanomechanics of cytoskeletal components, i.e., the monomeric feature of cytoskeletal filaments at microscale, the relation between the helical structure and the mechanical properties, and the interaction between the protein filaments and the surrounding environment, such as cytosol, filamentous proteins, electrical fields, etc. The thesis starts with a comprehensive review of the existing cytoskeletal filaments models. It is followed by the molecular structural mechanics models developed for microtubules and actin filaments. Subsequently, the models with monomeric feature were employed to identify the origin of the inter-protofilament sliding and its role in bending and vibration of microtubules. After that, helix structure effects on the mechanics of cytoskeletal filaments were explored. A three-dimensional transverse vibration was reported for microtubules with chiral structures, where the bending axis of the cross-section rotates in an anticlockwise direction and the adjacent half-waves oscillate in different planes. The tension-induced bending was also studied for actin filaments as a result of the helicity. Then, the subcellular environment effect on the filament mechanics was explored. Attempts were also made to reveal the physics of the experimentally observed localized buckling of microtubules and the crucial role of the cross-linker in regulating microtubule stiffness. Also the role of actin-binding proteins in determining the stiffness of actin bundle was examined during the formation of filopodia protrusion. Finally, the studies were carried out for the microtubule vibration excited by the alternating external electric field. Strong correlation was achieved between the tubulin interaction and the frequency shift. Meanwhile, the unique feature of nanoscale microtubule-cytosol interface was studied in detail. Large reduction of the viscous damping of cytosol was achieved in the presence of the nanoscale solid-liquid interface. At the end of the thesis, the contributions of the dissertation research were summarised and remarks were given on future research directions.

In this paper, a free-standing polyethylene glycol diacrylate based polymer electrolyte films plasticized by organic plasticizer (glutaronitrile) have been studied. The films were investigated with DSC, SEM and EIS technologies and further explored their performance in battery. It is discovered that small polymer molecules reduce crystalline significantly thus the film gives ionic conductivity as high as 6*10-4 S/cm at room temperature. Moreover, the electrochemical stability of the film can be enhanced effectively by introducing Lithium bis(oxalato)borate(LiBOB) into the solid polymer electrolyte, which further guarantees their performance in Li-ion all-solid state batteries.

The microreactor technique has received considerable research attention due to its promising applications in organic chemistry. Compared to traditional organic synthesis, the employment of microreactor has several advantages. First, the small diameter of the microchannel can reduce the reagent mixing time to milliseconds, allowing fast heat transfer and thermal equilibrium. Second, higher yield and better selectivity are often observed for reactions carried out in a microreactor. Most importantly, reaction optimization and catalyst library generation can be rapidly achieved by the microreactor with reagents on a small scale. In the past few years, our group has been developing a capillary-based microreactor system that is capable of high throughput catalyst screening. This system consists of HPLC apparatus, syringe pumps and capillary tubings, which are all commonly used in the chemistry laboratory. Compared with the traditional chip-based microreactor, our system is easy to operate, and simple to modify. Additionally, it couples with gas chromatography (GC) or high-performance liquid chromatography (HPLC) for online analysis, providing near-real-time reaction monitoring. One of the applications we explored with our microreactor system was the homogeneous catalysis reaction. The first reaction tested was lanthanide-triflate catalyzed allylation of benzaldehyde with tetraallyltin. With GC online analysis, the reaction was successfully carried out in our microreactor system. The optimized reaction condition, 10% catalyst load/60 min reaction time in room temperature, was much milder compared with any published bench top conditions. The screening of 8 different catalysts for the reaction was accomplished within 2 hours, which led to a significantly shortened optimization time. The online enantiomeric separation analysis method was developed for a strong chiral Brønsted acid catalyzed asymmetric cyanide addition. Six chiral columns and various separation conditions were involved in the method development. Due to the incompatible issue between the reaction solvent and column bonded phases, a GC method was optimized and chose as our interfaced online analysis method.