Guliz Topcu’s research while affiliated with Hacettepe University and other places

Microrobots are of significant interest due to their smart transport capabilities, especially for precisely targeted delivery in dynamic environments (blood, cell membranes, tumor interstitial matrixes, blood–brain barrier, mucosa, and other body fluids). To perform a more complex micromanipulation in biological applications, it is highly desirable for microrobots to be stimulated with multiple stimuli rather than a single stimulus. Herein, the biodegradable and biocompatible smart micromotors with a Janus architecture consisting of PrecirolATO 5 and polycaprolactone compartments inspired by the anisotropic geometry of tadpoles and sperms are newly designed. These bioinspired micromotors combine the advantageous properties of polypyrrole nanoparticles (NPs), a high near-infrared light-absorbing agent with high photothermal conversion efficiency, and magnetic NPs, which respond to the magnetic field and exhibit multistimulus-responsive behavior. By combining both fields, we achieved an “on/off” propulsion mechanism that can enable us to overcome complex tasks and limitations in liquid environments and overcome the limitations encountered by single actuation applications. Moreover, the magnetic particles offer other functions such as removing organic pollutants via the Fenton reaction. Janus-structured motors provide a broad perspective not only for biosensing, optical detection, and on-chip separation applications but also for environmental water treatment due to the catalytic activities of multistimulus-responsive micromotors.

Natural gas has become a vital energy source due to its abundant availability and relatively low carbon emissions. However, the presence of impurities, such as sulfur compounds, nitrogen compounds, and acidic gases, poses significant challenges in both efficiently using natural gas and addressing its environmental impact. This chapter provides a comprehensive overview of hydrotreating techniques and methods for removing acidic gases during the pretreatment of natural gas. Hydrotreating involves catalytic processes like hydrodesulfurization (HDS) and hydrodenitrogenation (HDN), aimed at converting harmful compounds into less detrimental forms. Within this chapter, detailed discussions cover reaction mechanisms, various catalyst types, and the impact of process conditions on the efficacy of hydrotreating. Furthermore, the chapter explores multiple technologies utilized for eliminating acidic gases, such as carbon dioxide (CO2) and hydrogen sulfide (H2S), from natural gas streams. These methods include absorption, adsorption, and membrane separation. Offering significant insights, this chapter serves as a valuable resource for researchers and industry professionals involved in advancing cleaner and more efficient processes for natural gas pretreatment.