Loch Patrick, Schuchardt Dominik, Algara-Siller Gerardo, Markus Paul, Ottermann Katharina, Rosenfeldt Sabine, Lunkenbein Thomas, Schwieger Wilhelm, Papastavrou Georg, Breu Josef
Bavarian Polymer Institute, Department of Chemistry, University of Bayreuth, Universitätsstraße 30, D-95447 Bayreuth, Germany.
Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany.
Sci Adv. 2022 May 20;8(20):eabn9084. doi: 10.1126/sciadv.abn9084. Epub 2022 May 18.
Exploiting the full potential of layered materials for a broad range of applications requires delamination into functional nanosheets. Delamination via repulsive osmotic swelling is driven by thermodynamics and represents the most gentle route to obtain nematic liquid crystals consisting exclusively of single-layer nanosheets. This mechanism was, however, long limited to very few compounds, including 2:1-type clay minerals, layered titanates, or niobates. Despite the great potential of zeolites and their microporous layered counterparts, nanosheet production is challenging and troublesome, and published procedures implied the use of some shearing forces. Here, we present a scalable, eco-friendly, and utter delamination of the microporous layered silicate ilerite into single-layer nanosheets that extends repulsive delamination to the class of layered zeolites. As the sheet diameter is preserved, nematic suspensions with cofacial nanosheets of ≈9000 aspect ratio are obtained that can be cast into oriented films, e.g., for barrier applications.
要充分发挥层状材料在广泛应用中的潜力,需要将其剥离成功能性纳米片。通过排斥性渗透膨胀进行的剥离是由热力学驱动的,是获得仅由单层纳米片组成的向列型液晶的最温和途径。然而,这种机制长期以来仅限于极少数化合物,包括2:1型粘土矿物、层状钛酸盐或铌酸盐。尽管沸石及其微孔层状类似物具有巨大潜力,但纳米片的生产具有挑战性且麻烦,并且已发表的方法意味着要使用一些剪切力。在这里,我们展示了一种可扩展、环保且能将微孔层状硅酸盐伊利石完全剥离成单层纳米片的方法,该方法将排斥性剥离扩展到了层状沸石类别。由于片层直径得以保留,可获得具有≈9000纵横比的共面纳米片的向列型悬浮液,这些悬浮液可浇铸成取向膜,例如用于阻隔应用。