Overview of EP62-1HT
EP62-1HT is a two-component moderate heat curing epoxy system with a long working life of 12–24 hours at room temperature. It is suitable for many highly demanding aerospace, electronic, and specialty OEM applications, especially where resistance to aggressive chemicals is necessary, even at higher temperatures. It has versatile cure schedules that can be adapted to meet the needs of specific bonding applications, such as adhering an optical pinhole to borosilicate glass, as discussed in this case study.
Application
Electric fields, such as those generated by lasers, can be used to accelerate chemical reactions, but this requires understanding the mechanism of such reactions. Researchers from Stanford University irradiated a cyclohexane solution of cis-stilbene with a nonresonant nanosecond-pulsed IR field to probe one such reaction. In this setup, a nonresonant IR field passed through a solution of cis-stilbene and provided a strong electric field without being significantly absorbed, i.e., it entered and exited the reaction solution mostly unchanged or consumed, behaving similarly to a chemical catalyst. The authors designed and built a vessel to house the cis-stilbene solution while it was irradiated with IR laser and UV light. As part of the design process, the author went through several iterations of the vessel design before finally determining the optimal design. EP62-1HT played a key role in ensuring that critical components of this vessel remained adhered to each other, even in the presence of the solvent cyclohexane.
Key Parameters and Requirements
To design an appropriate vessel, the authors needed to ensure that the materials of construction were compatible with the chemicals and laser wavelengths. As noted previously, the author iteratively designed four different vessels before determining the optimal design based on the reproducibility of the spatial overlap of the UV and electric field lasers used to irradiate reaction solution samples. The optimal vessel’s main body was constructed of two borosilicate glass tubes, between which the authors installed a high-damage threshold pinhole with a diameter (ø) of 50 µm, enclosed within aluminum housing.
To read more about the requirements, see the accompanying images, and learn the results, please download the full case study here.
Download full case study
Reference
Van Den Berg, J. L.; Neumann, K. I.; Harrison, J. A.; Weir, H.; Hohenstein, E. G.; Martinez, T. J.; Zare, R. N. Strong, Nonresonant Radiation Enhances Cis – Trans Photoisomerization of Stilbene in Solution. J. Phys. Chem. A 2020, 124 (29), 5999–6008. https://doi.org/10.1021/acs.jpca.0c02732.
Neumann, K. I.; Measuring the catalytic impact of nonresonant, pulsed radiation on reactions in the gas and solution phases [Doctoral dissertation, Stanford University].