Dual‐templating surface gel into thin SSZ‐13 zeolite membrane for fast selective hydrogen separation

Abstract: Highly permeable zeolite membranes are desirable for fast gas separation in the industry. Reducing the membrane's thickness is deemed to be an optimal solution for permeability improvement. Herein, we report the synthesis route of thin SSZ‐13 zeolite membranes via the conversion of template‐contained surface gels. The synthesis gel is fully crystallized into crack‐free SSZ‐13 membranes assisted with dual templates of N, N, N‐trimethyl‐1‐adamantammonium hydroxide (TMAdaOH) and tetraethylammonium hydroxide (TEAOH). The specific functions of TMAdaOH for structure directing and TEAOH for crystallization regulating are well discussed. Thin surface gel layer is impregnated onto porous alumina with subsequent crystallization into a 500 nm thick membrane. This submicron‐thick membrane exhibits high H2 permeance with 50 × 10−8 mol s−1 m−2 Pa−1 during hydrogen separation. Meanwhile, the separation factors are retained around 23.0 and 31.5 for H2/C2H6 and H2/C3H8, respectively. This approach offers a possibility for obtaining high‐quality zeolite membranes for efficient hydrogen separation

Screen printing directed synthesis of covalent organic framework membranes with water sieving property

Screen printing is introduced to direct the synthesis of crack-free and thickness-tunable TpPa(OH)2 covalent organic framework membranes. A smooth precursor layer is firstly screen printed and then fully crystallised into TpPa(OH)2 membrane. Molecular-scale pores endow the membrane fast water-sieving property, which is promising in water desalination

A zeolite-like aluminophosphate membrane with molecular-sieving property for water desalination

Membrane desalination has been proposed as a promising strategy to address the worldwide challenge of water scarcity. The development of membrane desalination is impeded by the limited availability of membrane materials, thus, selective membranes with high water fluxes are in high demand. Therefore, the synthesis of a zeolite-like aluminophosphate membrane for water desalination is reported herein. An AlPO4-18 membrane without visible cracks was prepared on stainless steel nets via a seeded approach. The specific adsorption and diffusion properties of the AlPO4-18 membrane toward water were simultaneously investigated by vapor adsorption measurements and molecular simulation. A large adsorption capacity indicates the excellent water affinity of the AlPO4-18 membrane, and water gathering around other water molecules suggests stronger water-water interactions than framework-water interactions. Meanwhile, water molecules transport rapidly through the pores, assisted by a built-in pathway and directed diffusion. The as-synthesized membranes are further evaluated for water desalination. The desalination tests of seawater containing both single and multi-component ions demonstrate that the AlPO4-18 membrane is very selective for water transport, evidenced by very high rejection degrees for cations (>99%). Moreover, the AlPO4-18 membrane exhibits unprecedented high water fluxes (2.14 kg m(-2) h(-1) in average). The superior performances of good selectivity, high water permeability and high stability ensure the potential application of supported aluminophosphate membranes in desalination

MYB Transcription Factor <i>OsC1^PLSr</i> Involves the Regulation of Purple Leaf Sheath in Rice

Although several regulators associated with purple traits in rice have been identified, the genetic basis of the purple sheath remains unclear. In the present study, F2-1 and F2-2 populations were constructed using purple sheath (H93S) and green sheath (R1173 and YHSM), respectively. In order to identify QTL loci in purple sheaths, BSA analyses were performed on the two F2 populations. A crucial QTL for purple sheath was identified, tentatively named qPLSr6, and was located in the 4.61 Mb to 6.03 Mb region of chromosome 6. Combined with expression pattern analysis of candidate genes, LOC_Os06g10350 (OsC1PLSr) was suggested as a candidate gene. The homozygous mutant KO-1 and KO-2 created through CRISPR/Cas9 editing, lost their purple leaf sheath. The RT-PCR revealed that OsC1PLSr, anthocyanin synthase (ANS), diflavonol-4-reductase (DFR), flavanone-3-hydroxylase (F3H), and flavanone-3′-hydroxylase (F3′H) expression levels were dramatically down-regulated in the mutants. The yeast report system indicated that the 145–272 aa region at the C-terminal of OsC1PLSr is a positive transcriptional activation domain. The results indicated that OsC1PLSr synthesized anthocyanins by regulating the expression of ANS, DFR, F3H, and F3′H. This study provides new insights into the genetic basis of the purple sheath