Mixed-matrix membranes composed of mechanically strong, solution-processable polymers and highly selective ultramicroporous fillers (pore size < 7 Å) are superior candidate membrane materials for a variety of energy-intensive gas separation applications because of their structural tunability to achieve enhanced gas permeability and gas-pair selectivity. However, their industrial implementation has been severely hindered because inefficient compatibility of the polymer matrices and crystalline fillers results in poorly performing membranes with low filler capacity and interfacial defects. Herein, we report for the first time a unique strategy to fabricate highly propylene/propane selective mixed-matrix membranes (MMMs) composed of a hydroxyl-functionalized microporous polyimide (PIM-6FDA-OH) and an ultramicroporous, strongly size-sieving zeolitic imidazolate framework (ZIF-8). Excellent compatibility between PIM-6FDA-OH and ZIF-8 with selective filler loading up to 65 wt% resulted from N…O-H induced hydrogen bonding as evidenced by Fourier-transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The newly developed MMMs demonstrated unprecedented mixed-gas performance for C 3 H 6 /C 3 H 8 separation and outstanding plasticization resistance of up to at least 7 bar feed pressure. The reported fabrication concept is expected to be applicable to a wide variety of OH functionalized polymers and alternative tailor-made imidazolate framework materials designed for MMMs to achieve optimal gas separation performance.

Fitness cost is a common phenomenon in rice blast disease-resistance breeding. MiR396 is a highly conserved microRNA (miRNA) family targeting Growth Regulating Factor (OsGRF) genes. Mutation at the target site of miR396 in certain OsGRF gene or blocking miR396 expression leads to increased grain yield. Here we demonstrated that fitness cost can be trade-off in miR396-OsGRFs module via balancing growth and immunity against the blast fungus. The accumulation of miR396 isoforms was significantly increased in a susceptible accession, but fluctuated in a resistant accession upon infection of Magnaporthe oryzae. The transgenic lines over-expressing different miR396 isoforms were highly susceptible to M. oryzae. In contrast, overexpressing target mimicry of miR396 to block its function led to enhanced resistance to M. oryzae in addition to improved yield traits. Moreover, transgenic plants overexpressing OsGRF6, OsGRF7, OsGRF8, and OsGRF9 exhibited enhanced resistance to M. oryzae, but showed different alteration of growth. While overexpression of OsGRF7 led to defects in growth, overexpression of OsGRF6, OsGRF8, and OsGRF9 resulted in better or no significant change of yield traits. Collectively, our results indicate that miR396 negatively regulates rice blast disease- resistance via suppressing multiple OsGRFs, which in turn differentially control growth and yield. Therefore, miR396-OsGRFs could be a potential module to demolish fitness cost in rice blast disease-resistance breeding.

A highly contorted, carbon-rich intrinsically microporous polyimide (PIM-PI) made from spirobifluorene dianhydride and 3,3-dimethylnaphthidine (SBFDA-DMN) was employed as a precursor for the formation of carbon molecular sieve (CMS) membranes at pyrolysis temperatures from 550 to 1000 °C. The high carbon content of SBFDA-DMN (~84%) resulted in only 28% total weight loss during pyrolysis under a nitrogen atmosphere at 1000 °C. The development of the various microstructural textures was characterized by gas sorption analysis, Brunauer-Emmett-Teller (BET) surface area, X-ray diffraction, Raman spectroscopy, electrical conductivity, and gas transport properties. Heat treatment of a pristine SBFDA-DMN membrane at 550 °C resulted in reduced permeability for all gases (e.g.: P CO2 dropped from 4700 to 1500 barrer) as well as lower BET surface area from 621 to 545 m 2 g -1 . At 600 °C, new pores induced by pyrolysis increased the BET surface area to nearly that of the precursor and significantly improved gas separation performance. Above 600 °C, a progressive collapse of the micropores became evident with CMS membranes showing higher gas-pair selectivity but lower permeability. At 1000 °C, ultra-micropores comparable in size with the kinetic diameter of CH 4 emerged and induced a prominent molecular sieving effect resulting in very high CH 4 rejection. This strong size exclusion effect, further supported by gravimetric gas sorption measurements, resulted in unusually high N 2 /CH 4 and CO 2 /CH 4 selectivities of 35 and 1475, respectively.

promising energy efficient separation processes in the chemical separation industry. Its continued growth can be attributed to lower energy requirements translating to lower capital and operating cost as well as significantly reduced environmental impact compared to conventional thermal separation processes. Additionally, membrane technology offers the advantages of continuous process operation, modular design, and small system footprint and is predicted to be a main contributor to global energy-and carbon-reduction initiatives in the coming decades. [2] In 2008, the global membrane market was valued at ≈12 billion USD with a compound annual growth rate (CAGR) of ≈10%. [3] Reverse osmosis (RO) and nanofiltration (NF) membranes contribute significantly to the total global membrane sales with the majority of products comprising of variations of thin-film composite (TFC) membranes made by interfacial polymerization. Such highly crosslinked aromatic submicroporous (i.e., pore size < 4 Å) [4] polyamide TFC membranes-pioneered by John Cadotte-revolutionized the desalination industry due to their unprecedented combination of high water flux and salt rejection. [5][6][7][8] Surprisingly, despite their immense commercial success for aqueous RO and NF applications, the IP membrane formation process has not been implemented in other large-scale fluid separation processes, especially organic solvent nanofiltration (OSN) and gas separations. [9][10][11] Polymers of intrinsic microporosity (PIMs) are an emerging group of solution processible amorphous microporous materials (pore size < 20 Å) gaining significant attention in membranebased separations due to their ability to transcend the conventional permeability/selectivity trade-off relationships. [12][13][14][15] Such materials exhibit exceptionally high free volumes as a result of inefficient chain packing by architectural designs using highly rigid and contorted spirobisindane-, triptycene-, ethanoanthracene-, and Tröger's base-building blocks. [13,[16][17][18][19][20][21] To date, technical challenges associated with fabricating defect-free, inexpensive, thin-film composite membranes as well as the inability to achieve low-molecular-weight cutoffs (MWCOs) have severely limited the industrial use of PIM-based and similar membrane materials. For example, Cook et al. demonstrated successful Polymeric membranes with increasingly high permselective performances are gaining a significant role in lowering the energy burden and improving the environmental sustainability of complex chemical separations. However, the commercial deployment of newly designed materials with promising intrinsic properties for fluid separations has been stalled by challenges associated with fabrication and scale up of low-cost, high-performance, defect-free thin-film composite (TFC) membranes. Here, a facile method to fabricate next-generation TFC membranes using a bridged-bicyclic triptycene tetra-acyl chloride (Trip) building block with a large fraction of finely tuned structural submicroporosity (por...