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Rice (Oryza sativa) is one of the most important crops grown worldwide, and saline–alkali stress seriously affects the yield and quality of rice. It is imperative to elucidate the molecular mechanisms underlying rice response to saline–alkali stress. In this study, we conducted an integrated analysis of the transcriptome and metabolome to elucidate the effects of long-term saline–alkali stress on rice. High saline–alkali stress (pH > 9.5) induced significant changes in gene expression and metabolites, including 9347 differentially expressed genes (DEGs) and 693 differentially accumulated metabolites (DAMs). Among the DAMs, lipids and amino acids accumulation were greatly enhanced. The pathways of the ABC transporter, amino acid biosynthesis and metabolism, glyoxylate and dicarboxylate metabolism, glutathione metabolism, TCA cycle, and linoleic acid metabolism, etc., were significantly enriched with DEGs and DAMs. These results suggest that the metabolites and pathways play important roles in rice's response to high saline–alkali stress. Our study deepens the understanding of mechanisms response to saline–alkali stress and provides references for molecular design breeding of saline–alkali resistant rice. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel zwitterionic polymer was successfully synthesized. • The membrane was prepared by co-depositing with dopamine and zwitterionic polymer. • The membrane demonstrates excellent hydrophilicity and antifouling performance. • The membrane demonstrates exceptional selectivity for dye/salt solution. The exceptional hydrophilicity and charge equilibrium of zwitterionic polymers render them highly desirable as antifouling materials. In this study, a novel zwitterionic copolymer Poly(2-aminoethyl methacrylate-Ethyl acrylatesulfopropyl piperidine salt) [P(AE-EA)] was successfully synthesized. Subsequently, a novel tight-ultrafiltration (t-UF) antifouling membrane employed for dye/salt separation was fabricated by co-depositing dopamine (DA) and P(AE-EA) onto the polyphenylene sulfone (PPSU) membrane substrate. The polydopamine (PDA) and P(AE-EA) are covalently linked through the formation of a covalent bond via Michael addition and Schiff base reactions. By regulating the ratio of PDA and P(AE-EA), the optimized membrane shows a denser and hydrophilic selective layer. The composition and characteristics of the membrane are investigated by serial characterization. The electrostatic adsorption between the membrane surface and the pollutant can be effectively weakened by the incorporation of a zwitterionic polymer P(AE-EA) with neutral charged and hydrophilicity. The modified membrane demonstrates exceptional antifouling performance for BSA, high rejection towards both negatively and positively charged dyes (Congo red, Methylene blue, Methyl orange and Rhodamine B), as well as efficient salt permeance for NaCl, Na 2 SO 4 , MgCl 2 , Mg 2 SO 4 in comparison to that of the pure PPSU membrane. The results presented herein demonstrate the remarkable potential of the novel zwitterionic t-UF membrane for effectively separating dye/salt mixture solutions in the textile industry. [ABSTRACT FROM AUTHOR]

• A total of 930 metabolites were identified in quinoa sprouts. • 232 metabolites responded significantly to saline-alkali stress. • Saline-alkali stress decreased the concentration of flavonoids and phenolic acids. • Different metabolites were mainly enriched in flavonoid and amino acid pathways. Quinoa sprouts are a green vegetable rich in bioactive chemicals, which have multiple health benefits. However, there is limited information on the overall metabolic profiles of quinoa sprouts and the metabolite changes caused by saline-alkali stress. Here, a UHPLC-MS/MS-based widely targeted metabolomics technique was performed to comprehensively evaluate the metabolic profiles of quinoa sprouts and characterize its metabolic response to saline-alkali stress. A total of 930 metabolites were identified of which 232 showed significant response to saline-alkali stress. The contents of lipids and amino acids were significantly increased, while the contents of flavonoids and phenolic acids were significantly reduced under saline-alkali stress. Moreover, the antioxidant activities of quinoa sprouts were significantly affected by saline-alkali stress. The enrichment analysis of the differentially accumulated metabolites revealed that flavonoid, amino acid and carbohydrate biosynthesis/metabolism pathways responded to saline-alkali stress. This study provided an important theoretical basis for evaluating the nutritional value of quinoa sprouts and the changes in metabolites in response to saline-alkali stress. [ABSTRACT FROM AUTHOR]

• Elastic rGO/PI aerogels were prepared by the unidirectional freeze-drying method. • By adding TAB and rGO, the morphology is adjusted to a "porous honeycomb" structure. • Aerogel shows excellent pressure response range, sensitivity, and compression fatigue resistance. • The PI-TAB-rGO20 sensor exhibits good piezoresistive response at −50℃ and 180℃. Flexible conductive polyimide aerogels used for piezoresistive pressure sensors in harsh environments are often limited by brittleness, structural collapse, low elastic recovery, low sensitivity, and narrow pressure detection range. Herein, we report a simple and green method of ice-templating unidirectional solidification combined with freeze-drying and thermal imidization to obtain a flexible reduced graphene oxide/polyimide (rGO/PI) nanocomposite aerogels with a double crosslinked structure, which achieve a significant transformation of PI aerogels from brittleness to high flexibility. The strong layered structure and dense interlaminar porous network are established by the covalent crosslinking of 1,3,5-triaminophenoxybenzene (TAB) and the hydrogen bonding crosslinking of graphene oxide (GO), imparting the double crosslinked rGO/PI aerogels with unique "porous honeycomb" structure and excellent mechanical properties. Due to the synergistic effect of TAB, rGO, PI, and unidirectional freezing process, the double crosslinked rGO/PI nanocomposite aerogel shows low density (25 mg/cm3), high compression cycle stability (3000 cycles), wide pressure detection range (0–85.1 kPa), extremely short response time (about 129 ms) and excellent environmental resistance (maintaining high structural stability and pressure response even at high temperatures of 180 °C and low temperatures of −50 °C), suitable for detecting various motion signals. It is proved that the elastic double crosslinked rGO/PI nanocomposite aerogels have potential applications serving as candidate materials for piezoresistive sensors and wearable electronic protective equipment in the fields of national defense, military industry, aerospace, and other fields in extreme environments. [ABSTRACT FROM AUTHOR]

Heat shock transcription factors (HSFs), play a crucial role in plant growth, development and defense processes. The functions of some HSFs have been well studied in response some stresses in model plants. At present, the genome of the medicinal plant Cannabis sativa L. has been fully sequenced. Nevertheless, there is little known about the HSF genes family in Cannabis sativa L, as well as a lack of understanding of its evolutionary history. Herein, 18 HSFs were identified in the cannabis genome and phylogenetically classified into three groups based on the structural characteristics and phylogenetic analysis, including classes A (9 genes), classes B (8 genes), and classes C (1 gene). They were distributed over 9 of 10 chromosomes without chromosome 8. Then, the motif composition and evolutionary relationship of CsHSF proteins are discussed in detail, along with gene structures, cis -acting elements in the promoter, and synchronization analysis. Furthermore, our results also revealed that CsHSF transcription levels varied significantly among tissues, suggesting that the functions of CsHSF may be different. Finally, we found that red and blue light treatments had a significant effect on HSF genes expression and cannabinoids accumulation in vegetative organs of hemp young seedlings, implying the expression of HSF genes may regulate the content of cannabinoids under different light conditions. Although cannabinoid biosynthesis and response to light in vegetative organs of hemp young seedlings may not represent the mature stage of hemp, these results provided an essential theoretical basis to elucidate the regulatory mechanism of HSF in cannabinoid biosynthesis in the future. • A total of 18 HSFs were identified in the cannabis genome. • CsHSF transcription levels varied significantly among tissues. • There were large numbers of light responsiveness elements in all 18 CsHSF promoters. • Light treatment affected the expression of several stress-responsive HSF genes and the accumulation of cannabinoid in vegetative organs of hemp seedlings. [ABSTRACT FROM AUTHOR]

Eight compounds, including one sphingolipid ( 1), two flavonoids ( 2, 3), four sterols ( 4-7), and one amino acid ( 8), had been isolated and purified from Amaranthus retroflexus L. Their structures were elucidated on the basis of spectroscopic analyses, including 1D and 2D NMR and ESI-MS. Among them, 1-O- β-D-glucopyranosyl-(2S,3R,4R,8E)-2-[(2′R)-2′-hydroxytetracosanoylamino]-1,3,4-octadecanetriol-8-ene ( 1) was identified as a new compound, and α-spinasteryl-3-O- β-D-glucopyranoside ( 4), 3 β,12 β,20(S)-trihydroxydammar-24-ene-6-O- β-D-glucopyranoside ( 6), and 2 β,3 β-dihydroxy-30-norolean-12,20(29)-diene-23,28-dioic acid 28-O- β-D-glucopyranosyl ester ( 7) were isolated from this plant for the first time. This is the first more comprehensive report on chemical compositions of Amaranthus retroflexus L. [ABSTRACT FROM AUTHOR]

β- d -Glucopyranoside,(3β,12β,20E)-12,25-dihydroxydammar-20(22)-en-3-yl (pseudo-ginsenoside Rh2) and its 20Z-isomer were synthesized from ginsenoside Rh2 under a mild condition, via a simple three-step called acetylation, elimination–addition and saponification. In addition, their activities were evaluated by eight different human tumor cells, compared with ginsenoside Rh2 group. Results indicated that the reaction in the side chain might greatly enhance the anti-proliferative activity of ginsenosides. [ABSTRACT FROM AUTHOR]

Tartary buckwheat is rich in flavonoids, which not only play an important role in the plant-environment interaction, but are also beneficial to human health. Rutin is a therapeutic flavonol which is massively accumulated in Tartary buckwheat. It has been demonstrated that transcription factors control rutin biosynthesis. However, the transcriptional regulatory network of rutin is not fully clear. In this study, through transcriptome and target metabolomics, we validated the role of FtMYB102 and FtbHLH4 TFs at the different developmental stages of Tartary buckwheat. The elevated accumulation of rutin in the sprout appears to be closely associated with the expression of FtMYB102 and FtbHLH4. Yeast two-hybrid, transient luciferase activity and co-immunoprecipitation demonstrated that FtMYB102 and FtbHLH4 can interact and form a transcriptional complex. Moreover, yeast one-hybrid showed that both FtMYB102 and FtbHLH4 directly bind to the promoter of chalcone isomerase (CHI), and they can coordinately induce CHI expression as shown by transient luciferase activity assay. Finally, we transferred FtMYB102 and FtbHLH4 into the hairy roots of Tartary buckwheat and found that they both can promote the accumulation of rutin. Our results indicate that FtMYB102 and FtbHLH4 can form a transcriptional complex by inducing CHI expression to coordinately promote the accumulation of rutin. Tartary buckwheat is renowned for its high flavonoid content, particularly rutin. There are several new findings in this study: • We found that flavonoids, specifically rutin, were also abundant in sprout and seedling, and that the content decreased as the plant matured from sprout to seedling. • We discovered that two new transcription factors, FtMYB102 and FtbHLH4, can regulate rutin biosynthesis. • FtMYB102 and FtbHLH4 can interact with each other to form a transcriptional complex that regulates target genes expression. [ABSTRACT FROM AUTHOR]

Saline and alkaline stresses limit plant growth and reduce crop yield. Soil salinization and alkalization seriously threaten the sustainable development of agriculture and the virtuous cycle of ecology. Biofertilizers made from plant growth−promoting rhizobacteria (PGPR) not only enhance plant growth and stress tolerance, but also are environmentally friendly and cost-effective. There have been many studies on the mechanisms underlying PGPRs enhancing plant salt resistance. However, there is limited knowledge about the interaction between PGPR and plants under alkaline–sodic stress. To clarify the mechanisms underlying PGPR's improvement of plants' tolerance to alkaline–sodic stress, we screened PGPR from the rhizosphere microorganisms of local plants growing in alkaline–sodic land and selected an efficient strain, Bacillus altitudinis AD13−4, as the research object. Our results indicate that the strain AD13−4 can produce various growth-promoting substances to regulate plant endogenous hormone levels, cell division and differentiation, photosynthesis, antioxidant capacity, etc. Transcriptome analysis revealed that the strain AD13−4 significantly affected metabolism and secondary metabolism, signal transduction, photosynthesis, redox processes, and plant–pathogen interactions. Under alkaline–sodic conditions, inoculation of the strain AD13−4 significantly improved plant biomass and the contents of metabolites (e.g., soluble proteins and sugars) as well as secondary metabolites (e.g., phenols, flavonoids, and terpenoids). The 16S rRNA gene sequencing results indicated that the strain AD13−4 significantly affected the abundance and composition of the rhizospheric microbiota and improved soil activities and physiochemical properties. Our study provides theoretical support for the optimization of saline–alkali-tolerant PGPR and valuable information for elucidating the mechanism of plant alkaline–sodic tolerance. [ABSTRACT FROM AUTHOR]

To provide polyimide (PI) with high heat resistance and ultra-low coefficient of thermal expansion (CTE) for use in flexible display substrates, a novel diamine with bisbenzimidazole and bisamide groups, namely N,N'-(1H,1'H-[5,5'-bibenzo[d]imidazole]-2,2'-diyl)bis(4-aminobenzamide) (BZBA), was designed and successfully synthesized. Several poly(benzimidazole-amide-imide) (PBIAI) films were prepared by thermal imidization with 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 4,4'-oxydiphthalic anhydride (ODPA), 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA), and 4,4'-(hexafluoroisopropylindene)-diphthalic anhydride (6FDA), respectively. Among them, BZBA-BPDA has a high glass transition temperatures (T g = 345 °C) while achieving an extremely low coefficients of thermal expansion (CTE = 1.9 ppm K−1), meeting the processing requirements of polymer flexible substrates in OLED devices. The effects of different dianhydrides on the performance of PBIAIs were compared, providing a meaningful reference for further adjusting the PI molecular structure to meet specific requirements for industrial polymer films. [ABSTRACT FROM AUTHOR]

To achieve the superheat-resistant polymers for flexible display substrates, two new diamines, namely 6-amine-2-(4-aminobenzene)-1-methyl-benzimidazole (m -MePABZ), 5-amine-2-(4-amino-benzene)-1-methyl-benzimidazole (p -MePABZ) containing N-methyl benzimidazole (BI) were synthesized and a serials of poly(benzimidazole imide) (PBII) films were prepared through thermal imidization. Among them, the flexible polyimide (PI) film derived from m -MePABZ and pyromellitic dianhydride (PMDA) has an ultra-low coefficient of thermal expansion (CTE) down to 2.5 ppm K−1 and an outstanding high glass-transition temperature (T g) up to 431 °C. Furthermore, the employment of N-methyl overcame an issue of the high H 2 O-absorption of traditional PBIIs, and the effect of " para -" and " meta- connecting" methyl on molecular packing and properties of these PIs was investigated. These data provided a useful guide to develop high performance PBIIs by incorporating N-methyl. Image 1 • Two novel diamines (m -MePABZ and p -MePABZ) were successfully synthesized. • The effect of " para -" and " meta- connecting" methyl on molecular packing and properties of these PBIIs was investigated. • m -MePABZ-PMDA film illustrated an ultra-low CTE of 2.5 ppm K-1 and an extremely high T g of 431 °C. [ABSTRACT FROM AUTHOR]

To achieve polyimide-metal complexes with enhanced properties, 5-amine-2-(5-aminopyridin-2-yl)-1-methyl-benzimidazole (PyMePABZ) that contains stiff 2-(2′-pyridyl)benzimidazole (PyBI) was synthesized and exploited to construct the Cu(ΙΙ)-crosslinked polyimides (Cu-PIs). These Cu-PIs exhibited higher dielectric, thermal, and mechanical properties with an increase in Cu2+ content. Among them, their dielectric constants (εrS) were up to 43% superior to that of the neat PI, glass transition temperatures (Tgs) were all over 400 °C, and 5% weight loss temperature (T5%) maintained beyond 500 °C. These data indicate that the metal coordination crosslinking provided a useful guide to develop high performance PIs which possess potential application as useful high temperature capacitors. [ABSTRACT FROM AUTHOR]

Soil saline–alkalization inhibits plant growth and development and seriously affects crop yields. Over their long-term evolution, plants have formed complex stress response systems to maintain species continuity. R2R3-MYB transcription factors are one of the largest transcription factor families in plants, widely involved in plant growth and development, metabolism, and stress response. Quinoa (Chenopodium quinoa Willd.), as a crop with high nutritional value, is tolerant to various biotic and abiotic stress. In this study, we identified 65 R2R3-MYB genes in quinoa, which are divided into 26 subfamilies. In addition, we analyzed the evolutionary relationships, protein physicochemical properties, conserved domains and motifs, gene structure, and cis-regulatory elements of CqR2R3-MYB family members. To investigate the roles of CqR2R3-MYB transcription factors in abiotic stress response, we performed transcriptome analysis to figure out the expression file of CqR2R3-MYB genes under saline–alkali stress. The results indicate that the expression of the six CqMYB2R genes was altered significantly in quinoa leaves that had undergone saline–alkali stress. Subcellular localization and transcriptional activation activity analysis revealed that CqMYB2R09, CqMYB2R16, CqMYB2R25, and CqMYB2R62, whose Arabidopsis homologues are involved in salt stress response, are localized in the nucleus and exhibit transcriptional activation activity. Our study provides basic information and effective clues for further functional investigation of CqR2R3-MYB transcription factors in quinoa. [ABSTRACT FROM AUTHOR]

Saline-alkali stress seriously affects the yield and quality of crops, threatening food security and ecological security. Improving saline-alkali land and increasing effective cultivated land are conducive to sustainable agricultural development. Trehalose, a nonreducing disaccharide, is closely related to plant growth and development and stress response. Trehalose 6-phosphate synthase (TPS) and trehalose-6-phosphate phosphatase (TPP) are key enzymes catalyzing trehalose biosynthesis. To elucidate the effects of long-term saline-alkali stress on trehalose synthesis and metabolism, we conducted an integrated transcriptome and metabolome analysis. As a result, 13 TPS and 11 TPP genes were identified in quinoa (Chenopodium quinoa Willd.) and were named CqTPS1-13 and CqTPP1-11 according to the order of their Gene IDs. Through phylogenetic analysis, the CqTPS family is divided into two classes, and the CqTPP family is divided into three classes. Analyses of physicochemical properties, gene structures, conservative domains and motifs in the proteins, and cis-regulatory elements, as well as evolutionary relationships, indicate that the TPS and TPP family characteristics are highly conserved in quinoa. Transcriptome and metabolome analyses of the sucrose and starch metabolism pathway in leaves undergoing saline-alkali stress indicate that CqTPP and Class II CqTPS genes are involved in the stress response. Moreover, the accumulation of some metabolites and the expression of many regulatory genes in the trehalose biosynthesis pathway changed significantly, suggesting the metabolic process is important for the saline-alkali stress response in quinoa. [ABSTRACT FROM AUTHOR]

In this paper, we present a synthetic strategy for N-phenyl substituted benzimidazole-derived diamines, including 2-(4-(4-aminophenoxy) phenyl)-1-phenyl-1H-benzo[d]imidazole-5-amine (para-diamine) and 2-(3-(4-aminophenoxy) phenyl)-1-phenyl-1H-benzo[d]imidazole-5-amine (meta-diamine). Two distinct series of N-phenyl substituted poly (benzimidazole imide)s (PBIPIs) were synthesized via reaction with different aromatic dianhydrides. The simulation reveals distinct amine reaction activities of two diamine monomers. The obtained PBIPIs exhibit exceptional heat resistance attributed to N-phenyl substituted benzimidazole (BI). The temperature at which weight loss of 5 % (T 5%) is in the range of 491–595 °C under N 2 environment, while the glass transition temperature is 237–329 °C. The PBIPIs exhibit specific solubility characteristics due to the flexible ether linkage groups' non-coplanarity and bulky pendant benzene groups. The PBIPIs possess tensile strength between 108 and 142 MPa, a tensile modulus of 4.0–5.9 GPa, and an elongation at a break of 4.2–26.4 %, indicating excellent mechanical properties. Additionally, the PBIPI with controlled molecular weight generated from BPADA incorporating 2-(3-(4-aminophenoxy) phenyl)-1-phenyl-1H-benzo[d]imidazole-5-amine (B-BPADA-PA) demonstrates exceptional melt processability. B-BPADA-PA possesses remarkable melt stability since its minimum complex viscosity is only 2100 Pa⋅s at 400 °C, and its melt viscosity ratio is 1.34 at 380 °C. [Display omitted] • The N-phenyl substituted benzimidazole-derived diamines were designed by a cleverly synthetic strategy. • The PBIPIs possessed excellent thermal resistance and superior mechanical properties. • The PBIPIs exhibited good solubility characteristics and extremely low water absorption. • B-BPADA-PA exhibited good melt processability with a minimum complex viscosity of 2100 Pa⋅s at 400 °C. [ABSTRACT FROM AUTHOR]

A novel highly transparent polyimide film with reduced CTE value was synthesized by introducing bulky pendent group and amide unit and the effects of designed structures on the optical transparency and dimensional stability of polyimide film were studied in detail. [Display omitted] • Several PI films were fabricated by introducing bulky pendent group and amide unit. • The effects of introduced groups on the properties of PI films were studied. • The film possesses good optical properties with λ cutoff of 384 nm and T 450 nm of 81%. • The film with designed structure displays reduced CTE value of 45 ppm/℃. Monomers of 4,4′-((4-(trifluoromethyl)phenyl)methylene)bis(2,6-dimethylaniline) (3FTMDT) and N,N'-(2,2′-bis(trifluoromethyl)-[1,1′-biphenyl]-4,4′-diyl)bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxamide) (TA-TFMB) were synthesized and designed to fabricate polyimide film with simultaneously designed bulky pendent group and amide unit in polymer chains and their effects on the optical transparency and dimensional stability of films were investigated in detail. The prepared polyimide (3FTMDT/TA-TFMB) film possesses highly optical transparency (λ cutoff = 384 nm, T 450 nm = 81%, Haze = 0.86) and lighter color (L *=95.09, a *=-2.14, b *=6.44) with the in-plane coefficient of linear thermal expansion of 45 ppm/oC. Meanwhile, the film presents good thermal stability and mechanical properties, with a glass transition temperature (T g) of 337 °C and 5 wt% decomposition temperature of 459 °C under N 2 , the fracture strength and tensile modulus of the film are 105 MPa and 2.2 GPa, respectively. The film also exhibits low dielectric performances with intrinsic dielectric constant of 2.29 and dielectric loss of 8 × 10-3 at 10 KHz, and which could keep stable up to 280 °C. In addition, the film shows good solubility in common solvents and is easy to be processed. The highly transparent polyimide film with reduced coefficient of linear thermal expansion is expected to be used as substrate material for flexible display or other photoelectric fields. [ABSTRACT FROM AUTHOR]

Herein, novel isomeric diamines containing semi-N-methyl substituted bisbenzimidazole and derived polyimides (PIs) were successfully synthesized. Experimental data showed that the obtained PIs exhibited outstanding heat resistance and dimensional stability, including 5 % thermal weight loss temperature (Td5 %) of 547 ~ 557 °C, high glass transition temperature (Tg) of 407 ~ 423 °C, and low coefficient of thermal expansion (CTE) of 2.2 ~ 17.6 ppm/°C. The influence of molecular structure of isomeric diamines, including para and ortho substituted N-methyl, on the molecular packing and properties of polymer was discussed. As a result, the novel PIs showed lower CTE than traditional PABZ (5-amino-2-(4-aminobenzene)-benzimidazole) based PIs without bringing high water absorption. These high-performance PI films with matching CTE of copper have potential applications in flexible display substrates and printed circuit boards. [ABSTRACT FROM AUTHOR]

Membranes with low dielectric constant and high moisture resistance are the key material for miniaturized and integrated communication equipment as an interlayer dielectric layer. Here, a series of cross-linked PI aerogel membranes were prepared by co-polymerization and scraping coating technology. The introduction of the fluorinated blocks and benzimidazole ring structures can consequently garner novel PI aerogel membranes with fascinating dielectric properties and outstanding moisture resistance. The dielectric constants of the sample membranes are as low as 1.33 at 1 KHz and 1.32 at 1 MHz with dielectric loss as low as 0.0079 at 1 KHz and 0.0035 at 1 MHz. The water contact angle can reach 107.35° with a surface roughness value of 30.428 nm. Moreover, the PI aerogel membranes have high specific surface area and excellent thermal and mechanical properties. The thermal conductivity as low as 35.4 mW m−1 K−1 at room temperature indicates excellent thermal insulation performance. PIAM-2 is suitable as an interlayer dielectric layer for electronic components under harsh environment. In addition, the influence of surface roughness on surface wettability was also elaborated on which can provide a feasible method for the preparation of low dielectric materials with moisture resistance. [Display omitted] • PI aerogels are prepared by co-polymerization and scraping coating technology via supercritical CO 2 drying. • The synergistic effect of diamines makes aerogels with excellent thermal and mechanical property. • Thermal conductivity as low as 35.4 mW m−1K−1 indicates aerogels have super thermal insulation performance. • PIAM-2 has excellent moisture resistance with water contact angle of 107.35° and surface roughness of 30.428 nm. • Dielectric constant of PIAM-2 reaches 1.32 with dielectric loss 0.0035 at 1 MHz suitable as interlayer dielectric layers. [ABSTRACT FROM AUTHOR]

[Display omitted] • Newly poly(ionic liquid) with hydrophilicity but insoluble in water was synthesized. • The construction of hydrogen bonds between poly(ionic liquid) and membrane matrix. • Improved hydrophilicity, reduced irreversible fouling and high flux recovery ratios of the blended membranes. • The modified membrane shows excellent anti-fouling properties towards BSA. • The modified membrane exhibits outstanding removal for dyes (EB and CR). Membrane fouling is a key challenge in the process of utilizing polyphenylene sulfone(PPSU) ultrafiltration (UF) membranes. To address this issue, an amino-functionalized poly(ionic liquid), poly(1-vinyl-3-propylamine imidazolium bis(trifluoromethane sulfonyl) imide) (PIL[TFSI]), was synthesized via free radical polymerization and incorporated into the prepared UF membranes-based PPSU with nanochannels through nonsolvent induced phase separation method. 1H NMR, ATR-FTIR, XPS and EDS spectra verified the introduction of PIL[TFSI]. The AFM and SEM images showed the membrane possessed a classical asymmetrical structure, featuring a higher surface roughness and dense cortex with pits. The decreased water contact angle by the incorporation of PIL[TFSI] indicates the formation of an improved hydrophilic membrane surface. The hydrophilicity of the blended membranes was enhanced by the increasing incorporation of PIL[TFSI]. Meanwhile, the flux decreased slightly, but the selectivity improved significantly. The PIL[TFSI]/PPSU UF membrane with 5% PIL[TFSI] maintained a flux (275 L/m2 h) and a high rejection for bovine serum albumin (BSA) (>99.9%). Additionally, the blended membrane has a superior removal performance for Congo red (>99.9%) and Evans blue (>99.9%). More importantly, the PIL[TFSI]/PPSU UF membranes present excellent antifouling with an increased flux recovery rate from 60.2% to 91.1%. Furthermore, the existence of hydrogen bonds and π-π interactions between PIL[TFSI] and PPSU is conducive to the good stability and sustained hydrophilicity of blended membrane even after continuous immersion for a month. [ABSTRACT FROM AUTHOR]

• Aromatic heterocyclic PI aerogels have been prepared by supercritical CO2 drying. • By adding PABZ, the morphology structure of PI aerogels is adjusted to fiber-island from tangled nanofibers. • Aerogels show outstanding mechanical behavior and thermal insulation (0.05 W/m·K). • PI aerogels also have rapid self-extinguishing and excellent flame retardant. The poor mechanical properties of polyimide (PI) aerogels made from biphenyl-3,3′,4,4′-tetracarboxylic dianydride (BPDA) and 4,4′-oxidianiline (ODA) limit their application. In this paper, an aromatic heterocyclic diamine, 5-amino-2-(4-aminophenyl)benzimidazole (PABZ) was introduced into the BPDA/ODA backbone to improve the comprehensive performance. The obtained PI aerogels represented excellent mechanical properties. The compressive Young's modulus was up to 53.9 MPa and the stress at 10 % strain was as high as 2.39 MPa. Meanwhile, the tensile Young's modulus ranged from 234 to 464 MPa and the tensile strength was up to 2.40 MPa. At the same time, all formulations of PI aerogels possessed outstanding thermal insulation, superb flame resistant and self-extinguishing performances, promising to be good candidates for special protective materials. Furthermore, the correlation between changes in morphology and structure resulting from the introduction of PABZ and PI aerogel properties was systematically analyzed. [ABSTRACT FROM AUTHOR]

Membrane with high performance for dye/salt mixed solutions effective separation is desired for textile wastewater treatment. In this paper, a carboxylated poly(aryl ether nitrile) (PEN-COOH) tight ultrafiltration membrane was prepared to fractionate dye/salt by non-solvent induced phase separation with PEG6000 as additive. Due to the synergistic effect of the strong electricity absorption of inherent -CN on poly(aryl ether nitrile) and the ionization of -COOH, PEN-COOH membrane surface showed a strong electronegativity, which was beneficial to the efficient dyes removal by electrostatic repulsion effect. Meanwhile, it was conducive to moderately reducing the membrane denseness to improve permeability. Dextran solute retention experiment showed that PEN-COOH membrane had a molecular weight cut-off of 31,000 Da, corresponding to an effective surface average pore of 7.7 nm. It had a hydraulic permeability of 2.9 L m−2 h−1 bar−1. Compared with those membranes prepared by commercially available materials, PEN-COOH membrane showed unparalleled separation performance advantages. Its pure water flux reached 401.2 L m−2 h−1, while maintaining high retention efficiency of electronegative dyes (> 99%) and low rejection rate of salts (< 10%) under 0.1 MPa driving pressure. PEN-COOH membrane also showed good anti-dye-fouling durability and excellent dye separation performance under varied pH, temperature and pressure, making it a promising membrane for textile wastewater treatment. [Display omitted] • A PEN-COOH TUF membrane was prepared for efficient fractionation of dye/salt mixed solutions. • The strong electronegativity and high porosity ensured excellent dye rejection performance of PEN-COOH membrane. • It owned a PWF of 401.2 L m−2 h−1, complete retention of electronegative dye and low salt rejection rate. [ABSTRACT FROM AUTHOR]

Novel diamines containing spirobisbenzoxazole scaffold structure were successfully synthesized. These diamines were homopolymerized with commercial 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and cyclohexanedianhydride (H'PMDA) to prepare a series of benzoxazole based polyimides (PBOIs). The obtained PBOIs exhibited good organic solubility and outstanding thermal properties, including glass transition temperature (T g) of 355–400 °C and 5% thermal decomposition temperatures (T d5%) of 474–490 °C. Meanwhile, these polymer films exhibited excellent mechanical strength, such as tensile strength of 79.4–92.1 MPa and elongation at break of 19.5%∼31.2%. In addition, such PBOIs have been proved to be novel microporous polymer with pore width distribution of 5–7 Å and BET surface area of 281–378 m2/g. The permeability-selectivity relationship of H'PMDA based PBOIs was close to the 2008 Robeson upper bound for CO 2 /CH 4 and O 2 /N 2 gas pairs, showing promise in the field of gas separation. [Display omitted] • Spirobibenzoxazole scaffold based Polyimides. • Good solubility and microporosity. • The permeability-selectivity relationship of H'PMDA based polyimides for CO 2 /CH 4 and O 2 /N 2 gas pairs close to the 2008 Robeson upper bound. [ABSTRACT FROM AUTHOR]

To prepare colorless polyimides (CPIs), two novel diamines, namely 6-amino-2-(2′-methyl-4′-aminobenzene)-N-phenylbenzimidazol (5a) and 6-amino-2-(2′-trifluoromethyl-4′-aminobenzene)-N-phenylbenzimidazol (5b) were synthesized, and two series of polyimides derived from them were developed. Except for the inherent asymmetric structures, the twisted moieties had been successfully incorporated in the benzimidazole dianmines through 2′- and N-substituents. The loose chain packing and hindered charge transfer (CT) interaction caused by the askew and distorted segments provided the polyimides with excellent optical transparency (80% transmittance at 400 nm, semi-alicyclic series), while the resulting films inherited the unique superheat-resistance of poly(benzimidazole imide)s (PBIIs), e.g., high glass-transition temperatures (up to 402 °C). Such outstanding optical and thermal properties expanded their application as heat-resistant colorless materials. Furthermore, the correlation between various 2′-substituents and characters of these PBII films was systematically analyzed. These data indicated that these colorless polyimides had potential application as optical and optoelectronic materials. [Display omitted] • Two novel benzimidazole dianmines containing 2′- and N-substituents (5a and 5b) were successfully synthesized. • Polyimide films with asymmetric and twisted structures were successfully synthesized. • The semi-aromatic poly(benzimidazole imide) films achieved colorlessness (T 400 = 80–81% and T g = 394–402 °C). • The effect of various 2′-substitutions on the properties of these N-phenyl-poly(benzimidazole imide)s was investigated. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel spirobisbenzoxazole-based polyimides of intrinsic microporosity were prepared. • The polyimides showed good solubility, excellent thermal and mechanical properties. • Discuss the rotation restriction and thermal annealing process on gas permeation behavior. Improving the processability and permeability of aromatic polyimides is a prerequisite for promoting the application in the field of gas separation membranes. Here, a series of novel spirobisbenzoxazole-based polyimides were synthesized. The novel spirobisbenzoxazole unit showed a larger rigid step size than the reported spirobisindane unit, which more effectively destroyed the molecular packing. As a result, the obtained aromatic polyimides showed good organic solubility and significantly improved gas permeability. Such polyimides were also considered as polymers of intrinsic microporous (PIMs) with ultra-micropore distribution of 5 ∼ 7 Å and high BET surface areas ranging from 373 to 449 m2/g. Meanwhile, the obtained polyimide membranes exhibited excellent thermal properties (T g > 400 °C) and outstanding mechanical properties (σ > 100 MPa). The effects of rotation restriction and thermal annealing process on gas permeation behavior were also studied. [ABSTRACT FROM AUTHOR]

Herein, we obtained porous hollow carboxyl-polysulfone (PH-CPSF) microspheres through non-solvent-induced phase separation (NIPS) method and simple modification, used as highly efficient adsorbents for removing cationic dyes from sewage. The resulting PH-CPSF microspheres possess a hollow core and sponge-like shell structure, with high surface area, durable chemical inertness and structural stability. The as-synthesized PH-CPSF microspheres deliver a desirable adsorption effect after deprotonation treatment, with an adsorption capacity reaching up to 154.5 mg g−1 at 25 °C (pH = 7) of methylene blue (MB). The inter-molecular interactions between MB and the surface of the PH-CPSF, including π-π interaction, hydrogen bonding, strong charge attraction and weak charge attraction endow the adsorption ability of the PH-CPSF. The pseudo-second-order kinetic model pronounces in the adsorption behavior, and the adsorption equilibrium data is fitted to the Langmuir model. Moreover, PH-CPSF microspheres can also be used as adsorption fillers for large-scale water purification, and a removal rate of 94.0% for MB can be achieved under a flow rate of 8000 L m−3 h−1. The reusability of 95.3% removal effect for PH-CPSF microspheres after 20 consecutive cycles can be attained by a simple regeneration treatment. The adsorption efficiency of the PH-CPSF microspheres was evaluated by variety of cationic and anionic dyes, with high adsorption capacity toward cationic dyes (100%) and less than 10% toward anionic dyes. These results manifest that PH-CPSF microspheres are a potential adsorbent with long-term purification capabilities, which are expected to be used in small and large-scale sewage treatment. [Display omitted] • Carboxyl polysulfone (PH-CPSF) microspheres were prepared by the non-solvent-induced phase separation and click reaction. • The as-obtained PH-CPSF possess honeycomb core-shell and porous hollow structure with abundant functional groups. • Highly selective cationic dyes remove efficiency, mechanical/chemical stability and reusability are achieved by PH-CPSF. • The functional PH-CPSF show its potential for large-scaled sewage purification. [ABSTRACT FROM AUTHOR]

A porous hollow polysulfone (donated as PHPSF) microspheres were prepared by non-solvent-induced phase separation using PEG as a porogen. The influence of the molecular weights (Mw) of PEG on the morphology and porous structure of the microspheres were investigated. As the Mw of PEG increasing from 600 to 10,000 g·mol–1, the viscosity of the system increases, leading to the increase of the viscosity difference between the dispersed phase and the continuous phase, and a delay in phase separation. Hence, the diameter and shell thickness of the obtained microspheres increase with the porosity reducing. Moreover, when the Mw of PEG is below 4000, the low |Δδ| between PEG and solvent is conducive to the formation of microporous structure with narrow pore distribution. The as-prepared PHPSF microspheres exhibit a separation efficiency of 6 times for MB than that of the original PSF microspheres. In addition, a reusability of 5 times of PHPSF is achieved even in the harsh acid or alkali condition. These results clarify the relationship between the different Mw of PEGs and microspheres morphology. Therefore, this kind of PHPSF microspheres holds a promising for the water organic pollution treatment. [Display omitted] • Porous hollow polysulfone (PHPSF) microspheres were prepared by the non-solvent-induced phase separation. • The porosity, macro/micropore size, diameter, pore morphology and specific surface area of the PHPSF microsphere is influenced by the molecular weight of PEG. • PHPSF microspheres have sub-micron surface pores and a honeycomb core-shell structure, showing high MB efficiency, excellent reusability and good mechanical/chemical stability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Poly(benzimidazole imide) films with asymmetric and twisted structures was successfully synthesized. • These poly(benzimidazole imide)s achieved more prominent properties than traditional poly(benzimidazole imide)s. • The semi-aromatic poly(benzimidazole imide)s were expected to be expanded as heat-resistant colorless materials. • The effect of various 2′-substitutions on the properties of these poly(benzimidazole imide)s was discussed. To prepare colorless polyimide (CPI) films with high thermal properties, an effective design strategy is incorporating asymmetric and twisted structures in the polymer chain-segments. Based on this strategy, 6,4′-diamino-2′-methyl-1-methyl-2-phenylbenzimidazole (5a) and 6,4′-diamino-2′-trifluoromethyl-1-methyl-2-phenylbenzimidazole (5b) were synthesized, and two series of their polyimides (semi- and fully aromatic series) were prepared, respectively. The obtained poly(benzimidazole imide)s (PBIIs) with loosely packed but rigid backbones possessed not only high glass transition temperature (T g) but also improved optical transparency. In particular, the semi-aromatic system achieved an excellent transmittance about 80% at 400 nm and an outstanding T g exceeding 400 °C. Furthermore, the influence of various 2′-substitutions on the combination properties of these poly(benzimidazole imide)s was systematically analyzed. These data expand the poly(benzimidazole imide)s as optical materials and provide a feasible method to prepare heat-resistant colorless polymers. [ABSTRACT FROM AUTHOR]

Nanosized titanium oxide (TiO2) material is a promising photocatalyst for the degradation of organic pollutants, whereas the difficulty of its recycling hinders its practical application. Herein, we reported the preparation of a novel titanium oxide/polysulfone (TiNPs/PSF) composite hollow microspheres by the combination of Pickering emulsification and the solvent evaporation technique and their application for the photodegradation of methyl blue (MB). P25 TiO2 nanoparticles dispersed on the surface of PSF microspheres. The porosity, density and photoactivity of the TiNPs/PSF composite microsphere are influenced by the TiO2 loading amount. The composite microsphere showed good methyl blue (MB) removal ability. Compared with TiO2 P25, and PSF, a much higher MB adsorption speed was observed for TiNPs/PSF microspheres benefited from their porous structure and the electrostatic attractions between the MB+ and the negatively charged PSF materials, and showed good degradation efficiency. For TiNPs/PSF composite microsphere with density close to 1, a 100% MB removal (10 mg L−1) within 120 min at a catalyst loading of 2.5 g L−1 can be obtained under both stirring and static condition, due to well dispersing of TiO2 particles on the microsphere surface and its stable suspending in water. For the non-suspended TiNPs/PSF composite microsphere with density bigger than 1, the 100% MB removal can be only obtained under stirring condition. The removal efficiency of MB for the composite microspheres retained 96.5%, even after 20 cycles. Moreover, this composite microsphere also showed high MB removal ability at acidic condition. The high catalysis efficiency, excellent reusability and good stability make this kind of TiNPs/PSF composite microsphere a promising photocatalyst for the water organic pollution treatment. [ABSTRACT FROM AUTHOR]

• Relationship between secondary metabolites and morphological variations. • 40 Cultivars of tartary buckwheat seeds from different regions. • Targeted metabolomics of flavonoids and anthraquinones. • Groats and hulls of tartary buckwheat seeds were studied respectively. Polyphenols (flavonoids and anthraquinones) are one of the most important phytochemicals in Fagopyrum tataricum L. Gaertn. (tartary buckwheat). However, the relationship between the polyphenols of tartary buckwheat seeds and their morphological variations is unclear. We developed a liquid chromatography–mass spectrometry-based targeted metabolomics method to study the chemical profiles of 60 flavonoids and 11 anthraquinones in 40 seed cultivars (groats and hulls). Both flavonoids and anthraquinones were related to variations in seed color; the fold change from yellowish-brown to black seeds was 1.24–1.55 in groats and 0.26–0.76 in hulls. Only flavonoids contributed to significant differences in seed shape; the fold change from long to short seeds was 1.29–1.78 in groats and 1.39–1.44 in hulls. Some differential metabolites were identified at higher concentrations in hulls than in groats. This study provides new insights into differences in polyphenols among tartary buckwheat seeds with different color and shape. [ABSTRACT FROM AUTHOR]