4-butoxybenzylidene-4’-butylaniline (BBBA) Sıvı Kristalinin Geniş Sıcaklık Aralığında İncelenmesi: Optik, Dielektrik, Kalorimetrik ve Kızılötesi Spektroskopik Analiz

Yıl 2021, Cilt: 10 Sayı: 2, 311 - 324, 07.06.2021

Atilla Eren Mamuk Nejmettin Avci

https://doi.org/10.17798/bitlisfen.847874

Cited By: 1

Öz

Bu çalışmada nematik ve farklı smektik mezofazlar sergileyen alkyloxy benzylidene alkylanilines sınıfına ait Schiff bazlı 4-butoxybenzylidene-4’-butylaniline (BBBA) sıvı kristalinin bazı fiziksel özellikleri incelenmiştir. Literatürde BBBA sıvı kristali üzerine çalışmalar oldukça az ve yetersizdir. Bu amaçla, morfolojik özelliklerinin belirlenmesi için optik tekstürleri mezofaz bölgelerinde ve faz geçiş bölgelerinde incelenmiştir. Optik tekstür analizlerinden BBBA’nın sergilediği mezofazlarda ortaya çıkan desenler belirlenmiştir. Ayrıca, dielektrik ölçümler ısıtma ve soğutma durumları için ayarı ayrı incelenerek her iki durum için dielektrik anizotropinin her bir mezofaz bölgesinde nasıl davrandığı araştırılmıştır. Yapılan araştırmalarda ısıtma ve soğutma durumlarında faz geçişler için termal histerezisin varlığı ortaya konulmuştur. Sıvı kristalik özellik sergilediği sıcaklık aralığında birçok mezofazın ortaya çıktığı BBBA’nın kızılötesi spektroskopik ölçümleri gerçekleştirilerek molekülün temel titreşim modları analiz edilmiştir. Ayrıca, BBBA’nın diferansiyel tarama kalorimetrisi yöntemi ile kalorimetrik ölçümleri hem ısıtma hem de soğutma durumları için yapılarak faz geçiş sıcaklıkları ve faz aralığı belirlenmiştir. Elde edilen kalorimetrik sonuçlar dielektrik ölçümlerden elde edilenler ile kıyaslanmıştır. Birçok mezofazı sergilemesi ve hakkında literatürde yeterince çalışmanın olmaması dolayısıyla BBBA sıvı kristali bilimsel araştırmalarda üzerine daha fazla araştırma yapılması gereken bir sıvı kristaldir.

Anahtar Kelimeler

Sıvı kristaller, dielektrik, optik, DSC, FTIR, tekstür

Teşekkür

Yazarlar, teknik desteklerinden dolayı Muğla Sıtkı Koçman Üniversitesi Araştırma Laboratuvarları Merkezi’ne teşekkür etmektedir.

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