No description available.

No description available.

Cellulose is the most abundant biopolymer in the world and the main component of paper. Modern society requires electronic devices to be more flexible and environmental friendly, which makes cellulose as a good candidate for the next generation of green electronics. However, lots of researches employed “paper-like” petroleum-based polymers to fabricate electronics rather than using real cellulose paper. Cellulose, as a representative of environmental friendly materials, caught into people's attention because of its sustainable nature, ease of functionality, flexibility and tunable surface properties, etc. There are some general challenges about using cellulose for electronics, such as its non-conductivity, porosity and roughness, but these features can be taken advantages of on certain occasions. This thesis focuses on the study of cellulose-based electronic devices by chemical or physical modification of microfibrillated cellulose (MFC). Particularly, three electronic devices were fabricated, including ionic diodes, electric double layer supercapacitors, pseudocapacitors. In addition, a rational design of dye-sensitized solar cell was investigated, although it was not directly cellulose-based, it led the way to the next generation of cellulose-based solar cells. The extraordinary physical and chemical properties of MFC were successfully leveled in those devices, in addition, inspiring and effective fabrication methods were proposed and carried out to solve the major problems faced by paper-based electronics, such as conductivity, flexibility, packaging and designs.

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

Drying is one of the most energy intensive operations of the chemical industry and accounts for about 6% of the total energy used by U. K. industry and about 2.5 of the overall energy demand of the U.K. Measurements taken on a typical industrial tumble dryer confirmed that generally convective dryers operate at thermal efficiencies less than 4 and that over 5Y of the energy input is lost as sensible heat content of the moist exhaust air. Any significant improvement in the thermal performance of dryers would therefore require a means of gainfully recovering the heat lost in the exhaust air. Some conventional heat recovery methods have been considered. Recirculation of exhaust air was shown to improve thermal efficiency but at the cost of reduced drying rates. Heat recovery by heat exchange was found unattractive because very large heat exchange surface areas would be required. A new type of adsorption heat pump (AHP) which may be operated either as a temperature swing cycle (TSC) or a pressure swing cycle (PSC), has therefore been proposed here for heat recovery from dryers. An experimental rig was built and used to investigate the adsorption of moisture on silica-gel in a 1.5 m. high, 0.25m. diameter column under conditions that simulate an industrial dryer, including high temperatures and humidities. Correlation of the experimental data led to the derivation of a polynomial function, similar to the system equilibrium equation, which relates the breakpoint capacity of the adsorbent to the breakpoint bed relative humidity. This function was used to develop a new theoretical model for predicting the performance of the proposed heat pump dryer. The predictions of this model enabled similar predictions obtained from two other models synthesized from various proposals put forward by other investigators previously to be tested against experimental results. This new model was found to be the most appropriate for the conditions encountered and was therefore considered to be the most suitable for predicting the performance of the adsorption heat pump drying system. Theoretical predictions based on this model indicate that the heat pump drL-er may be attractive for low temperature ( <1000C) drying. Under high temperature drying conditions low thermal efficiencies and unfavourably large adsorption bed size requirements make the heat pump unattractive.