Browsing by Author "Uzunlar, Rana"

Now showing 1 - 4 of 4

Open Access
Chemical reactions with Liesegang rings: generation of non-permanent thermal patterns
(Royal Society of Chemistry, 2025-01-08) Arı, Hatice; Uzunlar, Rana; Akbulut, Elif Sıla; Lagzi, Istvan; Baytekin, Bilge
Patterns are encountered and employed in nature, such as in the communication or growth of organisms and sophisticated behaviors such as camouflage. Artificial patterns are not rare, either. They can also be used in sensing, recording information, and manipulating material properties. Natural or artificial, most patterns have the colors of visible light. Patterns of infrared radiation are rare, even though some organisms and artificial sensors can detect infrared. In this work, we display a formation of non-permanent infrared Liesegang patterns in different gel media. We used the exothermic neutralization of the solid Mg(OH)2 formed as Liesegang patterns (LPs) to obtain these patterns. The LPs of infrared radiation (IR patterns) appear due to a temperature increase of up to 4 °C on the gel surface. We also show that it is possible to ‘read’ the information with an IR camera when the patterns are concealed and invisible. The idea can be expanded to other chemical systems and used to communicate with IR. On the other hand, the chemical reactions on the patterned solids can also be used to pattern other artificial material patterns directly inaccessible with the existing reaction–diffusion systems.
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Kurtuluş savaşı döneminde Adana'da ulusal direniş ve: Ramazanoğlu Ailesi
(Bilkent University, 2020) Sevim, Nurefşan; Uzunlar, Rana; Ramazanoğlu, Deniz; Dalkılıç, Ekin; Yöntem, Elif
Ramazanoğlu ailesi, Anadolu beyliklerinden Ramazanoğlu Beyliği'ni Adana ve çevresinde kuran Ramazanoğullarından gelmektedir ve Adana'nın en köklü ailelerinden biridir. Aile üyeleri tarihleri boyunca Adana'da yönetimde, eğitimde ve birçok alanda önemli rolleri üstlenmiş ve şehre çokça katkı sağlamışlardır. Bu çalışma, Kurtuluş Savaşı'nda Adana'nın durumuna ve Ramazanoğlu ailesinin milli müdafaaya olan katkılarının üzerine yoğunlaşmaktadır. I. Dünya Savaşı'ndan sonra Adana Anadolu'da İtilaf devletleri tarafından işgal edilen ilk şehirlerden olmuştur. Bu araştırma Adana'nın Kurtuluş Savaşı sırasında Fransızlar ile olan mücadelesinde Ramazanoğlu ailesinin üyelerinin gösterdiği fedakarlıkları ve katkıları incelemeyi amaçlamaktadır.
Embargo
Mechanochemical synthesis of antihistamine active pharmaceutical ingredient cinnarizine
(2025-02) Uzunlar, Rana
Mechanochemical methods are recognized as an appealing, greener methods for producing various molecular compounds. It has gained significance across multiple disciplines, such as chemistry and material science, due to its eco-conscious nature, allowing it to be performed without solvents or with only minimal amounts of solvent. Mechanochemical approaches also stand out as a prominent synthetic approach, enabling efficient and rapid processes compared to conventional synthesis approaches. Their synthetic capabilities through a range of solid-state transformations, yielding diverse compounds including inorganic, organic, polymeric, metal-organic-framework, and organometallic materials, have been proved over the decades. Yet another captivating illustration of mechanochemical reactions is seen in the effective pharmaceutical drugs and medicine preparations. This upward trajectory is evident in the increasing adoption of solid-state methodologies within pharmaceutical material science. These mechanochemical attempts are branched under a recently emerging field, namely “medicinal mechanochemistry,” and have been quite efficient in the synthesis of active pharmaceutical ingredients (APIs) and drugs such as paracetamol. They are also employed for the alteration of APIs through processes like the formation of salts or cocrystals. However, a synthetic pathway of many APIs in which mechanochemistry is used as a bimolecular solid-state reaction initiator, is not available yet. Here, we show that utilizing ball milling of the reactants through a simple SN2 reaction a first generation H1 antihistaminic API, cinnarizine, can be synthesized in moderate yields (25-50%). The milling and reaction parameters are explored in terms of product yields and a comparison with a conventional synthetic route is also provided. Milling produces cinnarizine in 1-60 minutes, compared to conventional organic synthesis, 4-24 hours. This route brings an innovative perspective to synthesizing widely used APIs in medicinal mechanochemistry and its potential applications in industry.
Open Access
Periodic stratification of colloids in a liquid phase produced by a precipitation reaction and gel swelling
(American Chemical Society, 2024-05-17) Tootoonchian, Pedram; Holló, Gábor ; Uzunlar, Rana; Lagzi, Istvan; Baytekin, Bilge
Pattern formation is a frequent phenomenon occurring in animate and inanimate systems. The interplay between the mass transport of the chemical species and the underlying chemical reaction networks generates most patterns in chemical systems. Periodic precipitation is an emblematic example of reaction–diffusion patterns, in which the process generates a spatial periodic structure in porous media. Here, we use the dormant reagent method to produce colloidal particles of Prussian blue (PB) and PB analogues at the liquid–gel interface. The generated particles produced a stable periodic stratification pattern in time in the liquid phase placed on top of the solid hydrogel. The phenomenon is governed by periodic swelling of the gel driven by the osmotic stress and stability of the formed particles. To illustrate the phenomenon, we developed an extended reaction–diffusion model, which incorporated the gel swelling and sedimentation effect of the formed colloids and could qualitatively reproduce the pattern formation in the liquid phase.