Synthetic Route of 121-98-2, Enzymes are biological catalysts that produce large increases in reaction rates and tend to be specific for certain reactants and products. 121-98-2, Name is Methyl 4-methoxybenzoate, SMILES is C1=CC(=CC=C1OC)C(OC)=O, belongs to esters-buliding-blocks compound. In a article, author is Gaebert, Chris, introduce new discover of the category.
Programming Viscosity in Silicone Oils: Reversible Tuning of Rheological Properties in 9-Anthracene Ester-Terminated Polydimethylsiloxanes
Programmable oils feature tunable viscosity and therefore possess potential for technical improvements and innovative solutions in many lubricated applications. Herein, we describe the first assessment of the variability of rheological properties of light-programmable 9-anthracene ester-terminated polydimethylsiloxanes (PDMS-As), including implications that arise with UV-light as an external trigger. We applied a modified rheometer setup that enables the monitoring of dynamic moduli during exposure to UV-light. The reversible dimerization of anthracene esters is used to either link PDMS chains by UV-A radiation (365 nm) or cleave chains by UV-C radiation (254 nm) or at elevated temperatures (>130 degrees C). Thermal cleavage fully restores the initial material properties, while the photochemical cleavage of dimers occurs only to a limited extent. Prolonged UV radiation causes material damage and in turn reduces the range of programmable rheological properties. The incomplete cleavage contributes to a gradual buildup of viscosity over a course of several switching cycles, which we suggest to result from chain length-dependent reaction kinetics. Material property gradients induced during radiation due to attenuation of the light beam upon its passing through the oil layer have to be considered, emphasizing the need for proper mixing protocols during the programming step. The material in focus shows integrated photorheology and is suggested to improve the performance of silicone oils in friction systems.
Synthetic Route of 121-98-2, Each elementary reaction can be described in terms of its molecularity, the number of molecules that collide in that step. The slowest step in a reaction mechanism is the rate-determining step.you can also check out more blogs about 121-98-2.