Entropy-driven self-assembly of chiral nematic liquid crystalline phases of AgNR@Cu2O hyper branched coaxial nanorods and thickness-dependent handedness transition


The chiral nematic liquid crystalline phase (CNLCP) of noble metal nanorods induces a strong chiroptical response due to their intrinsic physical and chemical properties. Here, we demonstrate that the formation of CNLCP of Ag nanorods (AgNRs) originates from their bent-shape and is the result of purely entropic effects. The chirality of the liquid crystalline phase of AgNR@Cu2O hyper branched coaxial nanorods (HBCNRs) can be switched from left-handed to right-handed by increasing Cu2O thickness. It is proposed that the increase of coating thickness decreases the curvature of nanorods, which induces variation of the twist constant (K2) and bend elastic constant (K3). The increased thickness also changes the direction of director with respect to the helical axis. In addition, hydrogen bonds can break the CNLCP, which can be attributed to their stronger effection compared to van der Waals forces and electrostatic interactions. In contrast to the variation of coating thickness, the surface morphology, constituents of the hybrid building blocks and polarity of the solvents do not play important roles in the handedness transition of the liquid crystalline phase. Furthermore, the results presented here give insight into the structure–property relationship and our strategy provides guidance for the synthesis of other inorganic chiral suprastructures driven by entropic effects.

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  1. [1]

    Shopsowitz, K. E.; Qi, H.; Hamad, W. Y.; Maclachlan, M. J. Free-standing mesoporous silica films with tunable chiral nematic structures. Nature 2010, 468, 422–425.

    Article  Google Scholar 

  2. [2]

    Hendry, E.; Carpy, T.; Johnston, J.; Popland, M.; Mikhaylovskiy, R. V.; Lapthorn, A. J.; Kelly, S. M.; Barron, L. D.; Gadegaard, N.; Kadodwala, M. Ultrasensitive detection and characterization of biomolecules using superchiral fields. Nat. Nanotechnol. 2010, 5, 783–787.

    Article  Google Scholar 

  3. [3]

    Kuzyk, A.; Schreiber, R.; Zhang, H.; Govorov, A. O.; Liedl, T.; Liu, N. Reconfigurable 3D plasmonic metamolecules. Nat. Mater. 2014, 13, 862–866.

    Article  Google Scholar 

  4. [4]

    Mitov, M. Cholesteric liquid crystals with a broad light reflection band. Adv. Mater. 2012, 24, 6260–6276.

    Article  Google Scholar 

  5. [5]

    Zhu, Z. N.; Liu, W. J.; Li, Z. T.; Han, B.; Zhou, Y. L.; Gao, Y.; Tang, Z. Y. Manipulation of collective optical activity in one-dimensional plasmonic assembly. ACS Nano 2012, 6, 2326-2332.

    Article  Google Scholar 

  6. [6]

    Li, Z. T.; Zhu, Z. N.; Liu, W. J.; Zhou, Y. L.; Han, B.; Gao, Y.; Tang, Z. Y. Reversible plasmonic circular dichroism of Au nanorod and DNA assemblies. J. Am. Chem. Soc. 2012, 134, 3322-3325.

    Article  Google Scholar 

  7. [7]

    Liu, W. J.; Zhu, Z. N.; Deng, K.; Li, Z. T.; Zhou, Y. L.; Qiu, H. B.; Gao, Y.; Che, S. A.; Tang, Z. Y. Gold nanorod@chiral mesoporous silica core-shell nanoparticles with unique optical properties. J. Am. Chem. Soc. 2013, 135, 9659-9664.

    Article  Google Scholar 

  8. [8]

    Han, B.; Zhu, Z. N.; Li, Z. T.; Zhang, W.; Tang, Z. Y. Conformation modulated optical activity enhancement in chiral cysteine and Au nanorod assemblies. J. Am. Chem. Soc. 2014, 136, 16104-16107.

    Article  Google Scholar 

  9. [9]

    Wu, X. L.; Xu, L. G.; Ma, W.; Liu, L. Q.; Kuang, H.; Kotov, N. A.; Xu, C. L. Propeller-like nanorod-upconversion nanoparticle assemblies with intense chiroptical activity and luminescence enhancement in aqueous phase. Adv. Mater. 2016, 28, 5907–5915.

    Article  Google Scholar 

  10. [10]

    Lv, J. W.; Hou, K.; Ding, D. F.; Wang, D. W.; Han, B.; Gao, X. Q.; Zhao, M.; Shi, L.; Guo, J.; Zheng, Y. L. et al. Gold nanowire chiral ultrathin films with ultrastrong and broadband optical activity. Angew. Chem., Int. Ed. 2017, 56, 5055–5060.

    Article  Google Scholar 

  11. [11]

    Li, S.; Xu, L. G.; Sun, M. Z.; Wu, X. L.; Liu, L. Q.; Kuang, H.; Xu, C. L. Hybrid nanoparticle pyramids for intracellular dual microRNAs biosensing and bioimaging. Adv. Mater. 2017, 29, 1606086.

    Article  Google Scholar 

  12. [12]

    Bailey, J.; Chrysostomou, A.; Hough, J. H.; Gledhill, T. M.; McCall, A.; Clark, S.; Ménard, F.; Tamura, M. Circular polarization in star-formation regions: Implications for biomolecular homochirality. Science 1998, 281, 672–674.

    Article  Google Scholar 

  13. [13]

    Liu, M. H.; Zhang, L.; Wang, T. Y. Supramolecular chirality in self-assembled systems. Chem. Rev. 2015, 115, 7304–7397.

    Article  Google Scholar 

  14. [14]

    Onsager, L. The effects of shape on the interaction of colloidal particles. Ann. N. Y. Acad. Sci. 1949, 51, 627–659.

    Article  Google Scholar 

  15. [15]

    Xu, Z.; Gao, C. Aqueous liquid crystals of graphene oxide. ACS Nano 2011, 5, 2908–2915.

    Article  Google Scholar 

  16. [16]

    Meuer, S.; Oberle, P.; Theato, P.; Tremel, W.; Zentel, R. Liquid crystalline phases from polymer-functionalized TiO2 nanorods. Adv. Mater. 2007, 19, 2073–2078.

    Article  Google Scholar 

  17. [17]

    Lemaire, B. J.; Davidson, P.; Ferré, J.; Jamet, J. P.; Panine, P.; Dozov, I.; Jolivet, J. P. Outstanding magnetic properties of nematic suspensions of goethite (a-FeOOH) nanorods. Phys. Rev. Lett. 2002, 88, 125507.

    Article  Google Scholar 

  18. [18]

    Li, L. S.; Walda, J.; Manna, L.; Alivisatos, A. P. Semiconductor nanorod liquid crystals. Nano Lett. 2002, 2, 557–560.

    Article  Google Scholar 

  19. [19]

    Rai, P. K.; Pinnick, R. A.; Parra-Vasquez, A. N. G.; Davis, V. A.; Schmidt, H. K.; Hauge, R. H.; Smalley, R. E.; Pasquali, M. Isotropic-nematic phase transition of single-walled carbon nanotubes in strong acids. J. Am. Chem. Soc. 2006, 128, 591–595.

    Article  Google Scholar 

  20. [20]

    Kim, J.; de la Cotte, A.; Deloncle, R.; Archambeau, S.; Biver, C.; Cano, J. P.; Lahlil, K.; Boilot, J. P.; Grelet, E.; Gacoin, T. LaPO4 mineral liquid crystalline suspensions with outstanding colloidal stability for electro-optical applications. Adv. Funct. Mater. 2012, 22, 4949–4956.

    Article  Google Scholar 

  21. [21]

    Wang, X. S.; Zou, Y. C.; Zhu, J. R.; Wang, Y. Silver cholesteric liquid crystalline: Shape-dependent assembly and plasmonic chiroptical response. J. Phys. Chem. C 2013, 117, 14197–14205.

    Article  Google Scholar 

  22. [22]

    Dressel, C.; Reppe, T.; Prehm, M.; Brautzsch, M.; Tschierske, C. Chiral self-sorting and amplification in isotropic liquids of achiral molecules. Nat. Chem. 2014, 6, 971–977.

    Article  Google Scholar 

  23. [23]

    Nayani, K.; Chang, R.; Fu, J. X.; Ellis, P. W.; Fernandez-Nieves, A.; Park, J. O.; Srinivasarao, M. Spontaneous emergence of chirality in achiral lyotropic chromonic liquid crystals confined to cylinders. Nat. Commun. 2015, 6, 8067.

    Article  Google Scholar 

  24. [24]

    Cestari, M.; Diez-Berart, S.; Dunmur, D. A.; Ferrarini, A.; de la Fuente, M. R.; Jackson, D. J. B.; Lopez, D. O.; Luckhurst, G. R.; Perez-Jubindo, M. A.; Richardson, R. M. et al. Phase behavior and properties of the liquid-crystal dimer 1”,7”-bis(4-cyanobiphenyl-4’-yl) heptane: A twist-bend nematic liquid crystal. Phys. Rev. E 2011, 84, 031704.

    Article  Google Scholar 

  25. [25]

    Dozov, I. On the spontaneous symmetry breaking in the mesophases of achiral banana-shaped molecules. Europhys. Lett. 2001, 56, 247–253.

    Article  Google Scholar 

  26. [26]

    Jansze, S. M.; Martínez-Felipe, A.; Storey, J. M. D.; Marcelis, A. T. M.; Imrie, C. T. A twist-bend nematic phase driven by hydrogen bonding. Angew. Chem., Int. Ed. 2015, 54, 643–646.

    Google Scholar 

  27. [27]

    Jiu, J.; Araki, T.; Wang, J.; Nogi, M.; Sugahara, T.; Nagao, S.; Koga, H.; Suganuma, K.; Nakazawa, E.; Hara, M. et al. Facile synthesis of very-long silver nanowires for transparent electrodes. J. Mater. Chem. A 2014, 2, 6326–6330.

    Article  Google Scholar 

  28. [28]

    van der Kooij, F. M.; Lekkerkerker, H. N. W. Formation of nematic liquid crystals in suspensions of hard colloidal platelets. J. Phys. Chem. B 1998, 102, 7829–7832.

    Article  Google Scholar 

  29. [29]

    Dong, X. M.; Kimura, T.; Revol, J. F.; Gray, D. G. Effects of ionic strength on the isotropic-chiral nematic phase transition of suspensions of cellulose crystallites. Langmuir 1996, 12, 2076–2082.

    Article  Google Scholar 

  30. [30]

    Sciacca, B.; Mann, S. A.; Tichelaar, F. D.; Zandbergen, H. W.; van Huis, M. A.; Garnett, E. C. Solution-phase epitaxial growth of quasi-monocrystalline cuprous oxide on metal nanowires. Nano Lett. 2014, 14, 5891–5898.

    Article  Google Scholar 

  31. [31]

    Zhao, Y. X.; Fan, L. L.; Zhang, Y.; Zhao, H.; Li, X. J.; Li, Y. P.; Wen, L.; Yan, Z. F.; Huo, Z. Y. Hyper-branched Cu@Cu2O coaxial nanowires mesh electrode for ultra-sensitive glucose detection. ACS Appl. Mater. Interfaces 2015, 7, 16802–16812.

    Article  Google Scholar 

  32. [32]

    Rej, S.; Wang, H. J.; Huang, M. X.; Hsu, S. C.; Tan, C. S.; Lin, F. C.; Huang, J. S.; Huang, M. H. Facet-dependent optical properties of Pd-Cu2O core–shell nanocubes and octahedra. Nanoscale 2015, 7, 11135–11141.

    Article  Google Scholar 

  33. [33]

    Tabiryan, N.; Serak, S.; Dai, X. M.; Bunning, T. Polymer film with optically controlled form and actuation. Opt. Express 2005, 13, 7442–7448.

    Article  Google Scholar 

  34. [34]

    White, T. J.; Broer, D. J. Programmable and adaptive mechanics with liquid crystal polymer networks and elastomers. Nat. Mater. 2015, 14, 1087–1098.

    Article  Google Scholar 

  35. [35]

    Choi, J. K.; Haynie, B. E.; Tohgha, U.; Pap, L.; Elliott, K. W.; Leonard, B. M.; Dzyuba, S. V.; Varga, K.; Kubelka, J.; Balaz, M. Chirality inversion of CdSe and CdS quantum dots without changing the stereochemistry of the capping ligand. ACS Nano 2016, 10, 3809–3815.

    Article  Google Scholar 

  36. [36]

    Xiang, J.; Shiyanovskii, S. V.; Imrie, C.; Lavrentovich, O. D. Electrooptic response of chiral nematic liquid crystals with oblique helicoidal director. Phys. Rev. Lett. 2014, 112, 217801.

    Article  Google Scholar 

  37. [37]

    Cheng, G. Q.; Di, J. C.; Wang, Y. Chiroptical study of metal@semiconductor-molecule composites: Interaction between cysteine and Ag@Ag3PO4 core–shell hybrid nanorods. J. Phys. Chem. C 2015, 119, 22122–22130.

    Article  Google Scholar 

  38. [38]

    Di Gregorio, M. C.; Ben Moshe, A.; Tirosh, E.; Galantini, L.; Markovich, G. Chiroptical study of plasmon-molecule interaction: The case of interaction of glutathione with silver nanocubes. J. Phys. Chem. C 2015, 119, 17111–17116.

    Article  Google Scholar 

  39. [39]

    Wanger, C. D.; Riggs, W. M.; Davis, L. E.; Moulder, J. F.; Muilenberg, G. E. Handbook of X-Ray Photoelectron Spectroscopy; Perkin-Elmer Corporation: Eden Prairie, MN, USA, 1979.

    Google Scholar 

  40. [40]

    Espinós, J. P.; Morales, J.; Barranco, A.; Caballero, A.; Holgado, J. P.; González-Elipe, A. R. Interface effects for Cu, CuO, and Cu2O deposited on SiO2 and ZrO2. XPS determination of the valence state of copper in Cu/SiO2 and Cu/ZrO2 catalysts. J. Phys. Chem. B 2002, 106, 6921–6929.

    Article  Google Scholar 

  41. [41]

    Brookshier, M. A.; Chusuei, C. C.; Goodman, D. W. Control of CuO particle size on SiO2 by spin coating. Langmuir 1999, 15, 2043–2046.

    Article  Google Scholar 

  42. [42]

    Xu, J. F.; Ji, W.; Shen, Z. X.; Tang, S. H.; Ye, X. R.; Jia, D. Z.; Xin, X. Q. Preparation and characterization of CuO nanocrystals. J. Solid State Chem. 1999, 147, 516–519.

    Article  Google Scholar 

  43. [43]

    Wang, W. Z.; Wang, G. H.; Wang, X. S.; Zhan, Y. J.; Liu, Y. K.; Zheng, C. L. Synthesis and characterization of Cu2O nanowires by a novel reduction route. Adv. Mater. 2002, 14, 67–69.

    Article  Google Scholar 

  44. [44]

    Teo, J. J.; Chang, Y.; Zeng, H. C. Fabrications of hollow nanocubes of Cu2O and Cu via reductive self-assembly of CuO nanocrystals. Langmuir 2006, 22, 7369–7377.

    Article  Google Scholar 

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This work was supported by the National Natural Science Foundation of China (Nos. 20971051 and 21621001), and the Education Department of Jilin Province (No. 2016407). We are very grateful to Prof. Xudong Zhao for helpful discussion.

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Correspondence to Yu Wang or Jihong Yu.

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Cheng, G., Wang, Y., Liu, K. et al. Entropy-driven self-assembly of chiral nematic liquid crystalline phases of AgNR@Cu2O hyper branched coaxial nanorods and thickness-dependent handedness transition. Nano Res. 11, 1018–1028 (2018). https://doi.org/10.1007/s12274-017-1715-z

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  • chirality
  • circular dichroism
  • Ag nanorod (AgNR)@Cu2O
  • liquid crystals
  • chiroptical response