Strong acid-nonionic surfactant lyotropic liquid-crystalline mesophases as media for the synthesis of carbon quantum dots and highly proton conducting mesostructured silica thin films and monoliths
American Chemical Society
10265 - 10271
Item Usage Stats
Lyotropic liquid-crystalline (LLC) materials are important in designing porous materials, and acids are as important in chemical synthesis. Combining these two important concepts will be highly beneficial to chemistry and material science. In this work, we show that a strong acid can be used as a solvent for the assembly of nonionic surfactants into various mesophases. Sulfuric acid (SA), 10-lauryl ether (C12E10), and a small amount of water form bicontinuous cubic (V1), 2Dhexagonal (H1), and micelle cubic (I1) mesophases with increasing SA/ C12E10 mole ratio. A mixture of SA and C12E10 is fluidic but transforms to a highly ordered LLC mesophase by absorbing ambient water. The LLC mesophase displays high proton conductivity (1.5 to 19.0 mS/cm at room temperature) that increases with an increasing SA content up to 11 SA/ C12E10 mole ratio, where the absorbed water is constant with respect to the SA amount but gradually increases from a 2.3 to 4.3 H2O/C12E10 mole ratio with increasing SA/C12E10 from 2 to 11, respectively. The mixture of SA and C12E10 slowly undergoes carbonization to produce carbon quantum dots (c-dots). The carbonization process can be controlled by simply controlling the water content of the media, and it can be almost halted by leaving the samples under ambient conditions, where the mixture slowly absorbs water to form photoluminescent c-dot-embedded mesophases. Over time the c-dots grow in size and increase in number, and the photoluminescence frequency gradually shifts to a lower frequency. The SA/C12E10 mesophase can also be used as a template to produce highly proton conducting mesostructured silica films and monoliths, as high as 19.3 mS/cm under ambient conditions. Aging the silica samples enhances the conductivity that can be even larger than for the LLC mesophase with the same amount of SA. The presence of silica has a positive effect on the proton conductivity of SA/C12E10 systems.
Semiconductor quantum dots
Surface active agents
Carbon quantum dots
Lyotropic liquid crystalline
Mesostructured silica films
Published Version (Please cite this version)http://dx.doi.org/10.1021/acs.langmuir.5b02225
Showing items related by title, author, creator and subject.
Bias in bonding behavior among boron, carbon, and nitrogen atoms in ion implanted a-BN, a-BC, and diamond like carbon films Genisel, M. F.; Uddin, M. N.; Say, Z.; Kulakci, M.; Turan, R.; Gulseren, O.; Bengu, E. (2011)In this study, we implanted Nþ and Nþ 2 ions into sputter deposited amorphous boron carbide (a-BC) and diamond like carbon (DLC) thin films in an effort to understand the chemical bonding involved and investigate possible ...
Shi, L.; Rohringer, P.; Suenaga, K.; Niimi, Y.; Kotakoski, J.; Meyer, J. C.; Peterlik, H.; Wanko, M.; Cahangirov, S.; Rubio, A.; Lapin, Z. J.; Novotny, L.; Ayala, P.; Pichler, T. (Nature Publishing Group, 2016-04)Strong chemical activity and extreme instability in ambient conditions characterize carbyne, an infinite sp1 hybridized carbon chain. As a result, much less has been explored about carbyne as compared to other carbon ...
Dhiman, R.; Petrunin V.; Rana, K.; Morgen P. (2011)Synthesis of structured silicon carbide materials can be accomplished using wooden materials as the carbon source, with various silicon impregnation techniques. We have explored the low cost synthesis of SiC by impregnation ...