408,523 research outputs found
Mesoporous materials
No full textRecently, mesoporous metal films containing high surface areas have been produced electrochemically by using lyotropic liquid crystalline phases as templating agents. The main advantage is the versatility of this method, where other materials can be prepared. This thesis describes three areas with the common theme of the electrodeposition of materials in the presence of lyotropic liquid crystals.The first area looks at the attempts to polymerise aniline in the hexagonal phase of C16EO8 and to characterise the films made. Although aniline could electropolymerise in a lyotropic liquid crystalline system, no evidence for nanostructure could be obtained.The next area studies the diffusion of the ferricyanide redox couple in the presence of Brij® 56; which may give a clearer picture of carrying out electrochemistry in the regular structured lyotropic liquid crystalline phases of a surfactant. Ferricyanide chemistry appeared more reversible in the surfactant system, and a timescale appeared to exist for the organisation of the liquid crystalline phase of Brij® 56 into equilibrium.The third area studies the electrodeposition of mesoporous palladium (Pd). Mesoporous Pd prepared electrochemically from the hexagonal phase of C16EO8 at room temperature has already been shown by Guerin to improve the performance of pellistors. Our work sets out to recreate and extend the experimental conditions when using a cheaper alternative surfactant, i.e. Brij® 56. The main purpose is to find the conditions suitable to deposit Pd on pellistors for comparison with the data obtained by Guerin. Electrodeposition of Pd in the hexagonal phase of Brij® 56 was possible on SRL 136a pellistors, and exposing them to methane showed evidence of sensitivity.Most importantly, the combination of the three areas show the different facets to electrodeposition in the lyotropic liquid crystalline phases of a surfactant, and that a cheap and widely available surfactant, i.e. Brij® 56, can be used to construct a gas sensor.</p
The Relation of Trifluralin to Collar Rot of Texas Gourd Caused by Fusarium Solani f. sp. Cucurbitae
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A Novel Approach for Studying Gene Expression in the Cell Cycle Reveals Coordinate and Independent Regulation of the H4 Multigene Family in Cycling and Non-growing Tetrahymena
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