Controlling crystal size and shape of zeolitic materials is an effective wayt op romote their mass transport and catalytic properties.H erein, we report as ingle step,N a +and porogen-free crystallization of MFI hierarchicala rchitecture made up of aligned nanocrystals with reduced b-axis thickness (5-23 nm) and adjustable Si/Al ratios between 35 to 120, employingt he commonly used tetrapropylammonium hydroxide (TPAOH) and tetrabutylammonium hydroxide (TBAOH) as structure-directing agents (SDAs). Homogeneous nucleation driven by both SDAs and subsequent SDAexchange induced dissolution-recrystallization are responsible for the formation of such structure.The enhanced textural and diffusion properties account for an otable exaggeration of propene selectivity and catalyst lifetime in dimethyl ether-toolefins (DTO) conversion. This protocol is extendable to the rational synthesis of other hierarchical zeolites through crystallization process control.

Chiral expression from the molecular to macromolecular level, as well as aggregates, plays an important role in natural physiological activity. Therefore, understanding the chirality transfer mechanism will provide guidance for the design of new functional chiral materials. Herein, we have systematically investigated the chiral assembly and transfer from the molecular to morphological level in liquid crystalline block copolymers (LC-BCPs) induced by enantiopure tartaric acid (TA) as a chiral source. Both the experimental and theoretical results indicate that the self-organization of the liquid crystal side chains and H-bonding interactions formed between the chiral additive and LC-BCPs are key factors for chiral expression in the self-assembly of LC-BCPs doped with TA. Furthermore, the various morphologies, including particles, spheres, worms, helical cylinders, and spirals, were observed in the LC-BCPs using transmission electron microscopy. The strength of the liquid crystal related to the azobenzene side chain structure has a crucial effect on the morphological transition. This work provides guidance for the design of diverse chiral nanostructures in a chiral molecule-induced achiral polymer system and may establish a fabrication platform for chiral cryptography, optical metamaterials, and other potential applications.

A high‐silica zeolite ECNU‐13 (Si/Al=23) with a new three‐dimensional (3D) pore system and a nanosized morphology has been developed, consisting of multitudes of 10‐membered ring (10‐R) medium pores and one set of 8‐R small pores. A phase‐discrimination strategy was proposed to synthesize ECNU‐13 by regulating the gel compositions and nucleation processes that were used for preparing 12‐R large‐pore germanosilicate IM‐20 with the known UWY topology. The crystallization was directed towards forming one set of single four‐ring (s4r) composite building units together with one set of double four‐ring (d4r) rather than two different types of d4r units in IM‐20. The electron crystallographic investigations elucidated that the ECNU‐13 structure was composed of two kinds of polymorphs as a result of distinct atomic positionings in s4r units. In catalytic cracking of 1‐butene, ECNU‐13 exhibited high propene selectivity (55.6 %) and propene to ethylene molar ratio (>4.7) superior to well‐studied conventional ZSM‐5 zeolite catalyst.

Achieving strong and broadband circularly polarized colour responses in chiral inorganic materials is challenging. Here, we fabricated chiral mesostructured bismuth oxybromide (BiOBr) films (CMBFs) via hydrothermal growth using chiral sugar alcohols as symmetry‐breaking agents. The layered slabs of BiOBr crystals with weak van‐der‐Waals interactions are prone to mismatching due to the chiral driving force, resulting in hierarchically chiral arrangements of fine size. Three levels of chirality exist in the CMBFs: primary, helical distortion crystal lattices of a nanoflake, secondary, helical stacking of nanoflakes to form nanoplates, and tertiary, chiral vortexes arranged by nanoplates. The CMBFs displayed optical activities (OAs) over a wide wavelength range of 350–2500 nm with an anisotropic factor of up to 0.99, which led to a significant chirality‐dependent colour response to circularly polarized light. The high selectivity can be considered as the result of enhanced resonance due to structural‐handedness matching and the synergistic effect of multiple OAs.

Controlling crystal size and shape of zeolitic materials is an effective wayt op romote their mass transport and catalytic properties.H erein, we report as ingle step,N a +and porogen-free crystallization of MFI hierarchicala rchitecture made up of aligned nanocrystals with reduced b-axis thickness (5-23 nm) and adjustable Si/Al ratios between 35 to 120, employingt he commonly used tetrapropylammonium hydroxide (TPAOH) and tetrabutylammonium hydroxide (TBAOH) as structure-directing agents (SDAs). Homogeneous nucleation driven by both SDAs and subsequent SDAexchange induced dissolution-recrystallization are responsible for the formation of such structure.The enhanced textural and diffusion properties account for an otable exaggeration of propene selectivity and catalyst lifetime in dimethyl ether-toolefins (DTO) conversion. This protocol is extendable to the rational synthesis of other hierarchical zeolites through crystallization process control.

circular dichroism, [3] electronic circular dichroism [4] and Raman optical activity, [5] has been used in both quantitative analysis and absolute configuration study of the enantiomers. However, the feasibility of enantiomeric discrimination by chiral chromatography strongly depends on molecular polarity and mass of enantiomers, which narrows applicable conditions and molecules for each chiral column. Chiral spectroscopy is impossible to be used for enantioselective discrimination of racemates or chiral molecules with inherently weak optical response suffering from poor resolution and low sensitivity. [6] Recently, we developed new strategies, PM-ChA [7] and SERS-ChA [8] of chiral nanostructured Au films (CNAFs) to enantiomers, which demonstrated enantiomeric determination, based on the selective generation of photomagnetic fields (PMFs) and selective enhancement of Raman scattering of enantiomeric molecules on CNAFs, respectively. These methods are available for all the enantiomers regardless of their sizes, polarities, or chromophores, which overcome the drawbacks of chromatography and spectroscopy.Silver (Ag) nanomaterials show strong SPR effects and excellent electrical conductivity, making them promising for plasmonic sensing systems and optoelectronic devices. [9] Therefore, doping with Ag should allow modulating the SPR and increasing conductivity of composite nanomaterials, which is expected to generate stronger local electromagnetic fields and further enhance the SERS intensities. This strategy provides the possibility for simultaneous enhancement of the PM-ChA and SERS-ChA effects of chiral noble metal nanomaterials. However, multi-metal compounding by the wet chemical deposition method sometimes suffers from difficulty in finding a reductant with appropriate reducing potential for simultaneous codeposition of metal ions in the precursor solution.Electrodeposition is a universal, efficient, and low-consumption technique for the preparation of Ag containing composite nanomaterials comparing with the other methods, [10] because deposition occurs in a very limited range on the electrode surface and the electrodeposition method allows precisely controlled reduction potential and duration time for Ag material preparation. [11] In addition, reduction reaction rates of different metal ions can be adjusted by changing the reduction potential, which makes them uniformly deposited Herein, the chiral nanostructured bimetallic Au-Ag films (CNAAFs) with both photomagnetic-chiral anisotropy to enantiomers (PM-ChA C-E ) and surface-enhanced Raman scattering-chiral anisotropy to enantiomers (SERS-ChA C-E ) for efficient enantiomeric discrimination are reported. The CNAAFs are synthesized by electrodeposition on n-type Si (n-Si) substrates with the assistance of N-acetyl-L/D-cysteine (S/R-NAC) as symmetry-breaking agents, which are consisted of polycrystalline Boerdijk-Coxeter-Bernal (BCB) tetrahelical structured Au-Ag alloy nanowires grown on n-Si substrates perpendicularly. The anisotropic factors of PM-ChA C-E ...

Achieving strong and broadband circularly polarized colour responses in chiral inorganic materials is challenging. Here, we fabricated chiral mesostructured bismuth oxybromide (BiOBr) films (CMBFs) via hydrothermal growth using chiral sugar alcohols as symmetry‐breaking agents. The layered slabs of BiOBr crystals with weak van‐der‐Waals interactions are prone to mismatching due to the chiral driving force, resulting in hierarchically chiral arrangements of fine size. Three levels of chirality exist in the CMBFs: primary, helical distortion crystal lattices of a nanoflake, secondary, helical stacking of nanoflakes to form nanoplates, and tertiary, chiral vortexes arranged by nanoplates. The CMBFs displayed optical activities (OAs) over a wide wavelength range of 350–2500 nm with an anisotropic factor of up to 0.99, which led to a significant chirality‐dependent colour response to circularly polarized light. The high selectivity can be considered as the result of enhanced resonance due to structural‐handedness matching and the synergistic effect of multiple OAs.

Quasicrystals attract considerable attention due to their unique physical and structural properties. An increasing number of quasicrystals have been reported from self-assembly processes in soft matter systems; however, no generic synthesis conditions that yield mesoscopic quasicrystals have been fully clarified yet. This paper presents a new synthesis system for mesoporous silica crystals that yields dodecagonal quasicrystals, employing a gemini cationic surfactant as a template, carboxyethylsilanetriol sodium salt as a co-structure-directing agent, and tetraethyl orthosilicate as a silica source. We show structural changes from cubic close packing to a composite of cubic and hexagonal close packings, and further to tetrahedral close packings derived from dodecagonal tilings with squares and triangles as the concentration of the co-structure directing agent is gradually decreased. These structural changes are attributable to the softening of the spherical micelles, i.e., the building units of the structure while in solution, considering that area-minimizing duals are energetically favored by the packing of soft spheres. A possible relevance of the present findings to a recent prediction on the stability of dodecagonal quasicrystalline dry foams is pointed out.