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BACKGROUND: Biological enhancement in organic wastewater treatment is currently considered an effective and economical method. As a biomass carrier, mycelial pellets are attracting increasing attention, with substantial progress recently being made. To investigate their bioaugmentation effect as a biomass carrier, mycelial pellets with immobilized phenol‐degrading bacteria were applied in a sequencing batch reactor. The phenolic compound removal efficiency of the mycelial pellet‐enhanced system was then studied and compared to the control aerobic activated sludge‐enhanced system. Finally, the settling velocity, internal structure, and surface properties were studied to explore the main bioaugmentation mechanisms of the mycelial pellets. RESULTS: The stable degradation effects of phenolic compounds and total organic carbon (TOC) were observed in both systems. In the mycelial pellet system, the biological removal efficiency was approximately 0.5 mg phenolic compounds L−1 d−1MLSS−1 and 0.4 mg TOC L−1 d−1MLSS−1, which was higher than the aerobic activated sludge system. Bioaugmentation by the pellets was mainly attributed to the structure of the connected macropores, the electrostatic attraction of positive charges, the adsorption of functional groups on the hypha surface, and flocculation due to the extracellular polymeric substances secreted on the pellet. CONCLUSION: The excellent phenolic compound removal efficiency and bioaugmentation effect of the mycelial pellets suggest their potential to enhance organic wastewater treatment as a biomass carrier. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Waste sludge produced from wastewater treatment has been regarded as a potential reservoir of microplastics. In order to investigate the effect of sludge microbial decomposition on the microplastics, polypropylene, polyethylene, polyvinyl chloride, and tire microplastics are chosen to investigate changes in their surface properties during anaerobic sludge treatment process. The results show that the intensity of oxygen-containing functional groups such as carbonyl and hydroxyl exhibits an increasing tread with anaerobic sludge microbial treatment time, indicating an enhanced hydrophilicity of microplastic surface, which is further confirmed by contact angle results. Correlation results show that carbonyl index can favorably reflect the impact of anaerobic sludge microorganisms on the surface properties of polyethylene and polyvinyl chloride microplastics, while the surface changes of polypropylene and styrene butadiene rubber tire microplastics can be characterized with the absorption peak areas in wavenumber range of 1 300 to 1 500 cm-1. This study can provide theoretical basis for further investigating the sludge microorganism-driven decomposition and reaction behavior of microplastics. [ABSTRACT FROM AUTHOR]

Polyimide substrates used in flexible display devices need to withstand very high temperatures and be highly thermally stable. The discovery of polyimides that satisfy these requirements, especially with high glass transition temperatures (Tg), has been a hot research topic. However, conventional structural design of polyimides requires domain knowledge and expertise. In addition, the latent polyimide structures can reach millions, making it impractical to navigate their structure–property landscapes under conventional experimental screening. To address this matter, we utilized a graph neural network to build a regression model for predicting polyimides' Tg and a classification model for two-step ensemble molecular screening. Eight polyimides were synthesized with Tg measured using differential scanning calorimetry (DSC) and these values were well matched to the predicted values of the regression model. Unlike common machine learning models, our models substantially learn the effect of specific functional groups on polyimides Tg and thus offer visual interpretation of the effect of functional group variations on Tg, providing an unknown performance metric (Rot2Ring) for designing molecules with specific Tg. Meanwhile, the model predicted Tg values of 8 205 096 polyimides and a comprehensive screening has been implemented. Finally, combined with chemical knowledge, we derived 110 alternative polyimide structures with Tg exceeding 400, which can be used by scientists for structure filtering. Furthermore, we propose an accessible toolkit – polyScreen, which enables predicting Tg from structures in one step even without programming experience and more prediction modules will be updated in the next releases. This work demonstrates the feasibility of accurate prediction of material properties, providing potential polyimides with excellent properties for flexible displays, membranes and fibers utilizing graph neural networks, and provides quantitative guidance for the design of polyimides. [ABSTRACT FROM AUTHOR]

To tolerate high processing temperature during the fabrication of low‐temperature polycrystalline silicon thin‐film transistors (LTPS–TFT) in flexible OLED devices, the polyimide (PI) films, which are used as substrate, should have ultra‐high glass transition temperature (Tg > 450°C) and ultra‐low coefficient of thermal expansion (CTE at 0–5 ppm K−1). In this paper, two novel heterocyclic monomers, namely, N,N'‐(xanthone‐2,7‐diyl)bis(4‐aminobenzamide) (p‐DAXBA) and N,N'‐(xanthone‐2,7‐diyl)bis(3‐aminobenzamide) (m‐DAXBA), which contain a xanthone moiety, are prepared and polycondensed with pyromellitic dianhydride (PMDA), respectively. PI films (PIa and PIb) with intrinsic high Tg and low CTE are designed from the perspective of rigid conjugate xanthone structure and hydrogen bonding interaction. It is found that the PIa films prepared by p‐DAXBA have better linear structure of molecular chains and show relatively higher Tg and lower CTE. The Tg of PIa‐40 is greater than 450°C, and CTE can reach as low as 2.7 ppm K−1, tensile strength of 179 MPa, modulus of 5.67 GPa, indicating potential application prospect as a flexible OLED substrate. [ABSTRACT FROM AUTHOR]

The silane coupling agent 3-aminopropyltriethoxysilane (KH-550) was used to modify the surface of two kinds of high-performance polyimide (PI) fibres (i.e., PI-1 and PI-2). The surface chemical composition, morphologies and roughness of modified PI fibres were characterised by XPS, SEM and AFM. Results showed that the elemental ratio between O and C, the surface oxygen concentration and the surface roughness increased with KH-550 concentration. However, the interfacial shear strength (IFSS) and interlaminar shear strength (ILSS) values of PI fibre/epoxy resin composites increased and then decreased with KH-550 concentration. When KH-550 concentration was increased to 4 wt%, the IFSS and ILSS values reached their maximum point. At this point, the IFSS values were found increase by 17.3% and 8.3% for PI-1 and PI-2, respectively, compared with their pristine state. Meanwhile, the ILSS values of PI-1- and PI-2-reinforced composites were found increase by 22.4% and 24.1%, respectively. GRAPHICAL ABSTRACT [ABSTRACT FROM AUTHOR]

ABSTRACT: A series of novel ultralow dielectric porous polyimide (PI) films containing adamantane groups was prepared via the thermolysis of polyethylene glycol (PEG) oligomers mixed into PI matrix. Scanning electron microscopy results indicated that the porous PI films showed closed pores with an average diameter of 120 ± 10 nm. Good thermal properties with 5% weight loss temperature of 499 °C in air atmosphere and glass transition temperature in excess of 310 °C were shown for porous PI films. Notably, the ultralow dielectric constant of porous PI films with 1.85 at 1 MHz was obtained and revealed via broadband dielectric spectroscopy. The effects of the chemical structure of the PI matrix and PEG content on the decomposition behavior of PEG and the performance of porous films were investigated. Wide‐angle X‐ray diffraction results indicated that the PI matrix with large d‐spacing generated weaker interactions between the PEG and PI backbone than those of PI matrix with small d‐spacing. As a result, the PEG for the PI matrix with large d‐spacing was completely decomposed. As indicated by the broadband dielectric spectroscopy results, lower dielectric porous PI films were prepared when the PEG contents in the PI matrix increased from 0 to 20 wt %. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 549–559 [ABSTRACT FROM AUTHOR]

Porous polyimide (PI) films with low dielectric constants and excellent thermal properties have been a pressing demand for the next generation of high‐performance, miniature, and ultrathin microelectronic devices. A series of novel porous PI films containing fluorenyl‐adamantane groups were prepared successfully via thermolysis of poly(ethylene glycol) (PEG) added in the PI matrix. The cross‐sectional morphologies of porous PI films showed closed pores with diameters ranging from 135 to 158 nm, which were uniform and regular in shape without interconnectivity. These porous PI films exhibited excellent thermal properties with a glass‐transition temperature at 376 °C whereas the 5% weight loss temperature in air excess of 405 °C due to enhanced rigidity afforded by fluorenyl‐adamantane groups. Accompanied by thermolysis content of PEG increasing from 0 to 20 wt %, the density of porous PI films decreased, and the corresponding porosity grew significantly from 0 to 11.48%. Depending on porosity, the dielectric constant and dielectric loss of porous PI films significantly declined from 2.89 to 2.37 and from 0.050 to 0.021, respectively. These excellent properties benefit the as‐prepared porous PI films for application as interlayer dielectrics, integrated circuit chips, or multichip modules in microelectronic fields. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47313. Novel porous polyimide films containing fluorenyl‐adamantane groups were prepared, which exhibited high Tg, low dielectric constant of 2.37, and dielectric loss of 0.021. [ABSTRACT FROM AUTHOR]

Language models exhibit a profound aptitude for addressing multimodal and multidomain challenges, a competency that eludes the majority of off-the-shelf machine learning models. Consequently, language models hold great potential for comprehending the intricate interplay between material compositions and diverse properties, thereby accelerating material design, particularly in the realm of polymers. While past limitations in polymer data hindered the use of data-intensive language models, the growing availability of standardized polymer data and effective data augmentation techniques now opens doors to previously uncharted territories. Here, we present a revolutionary model to enable rapid and precise prediction of Polymer properties via the power of Natural language and Chemical language (PolyNC). To showcase the efficacy of PolyNC, we have meticulously curated a labeled prompt-structure-property corpus encompassing 22 970 polymer data points on a series of essential polymer properties. Through the use of natural language prompts, PolyNC gains a comprehensive understanding of polymer properties, while employing chemical language (SMILES) to describe polymer structures. In a unified text-to-text manner, PolyNC consistently demonstrates exceptional performance on both regression tasks (such as property prediction) and the classification task (polymer classification). Simultaneous and interactive multitask learning enables PolyNC to holistically grasp the structure-property relationships of polymers. Through a combination of experiments and characterizations, the generalization ability of PolyNC has been demonstrated, with attention analysis further indicating that PolyNC effectively learns structural information about polymers from multimodal inputs. This work provides compelling evidence of the potential for deploying end-to-end language models in polymer research, representing a significant advancement in the AI community's dedicated pursuit of advancing polymer science., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

A novel polyamic acid (PAA from BAPMPO-BPDA) organogel was synthesized and characterized via dynamic light scattering (DLS), a classical rheometer, and diffusion wave spectroscopy (DWS). In situ monitoring was performed using a classical rheometer to observe the formation of the PAA organogel. The rheological curves confirm the formation of the PAA gel network and the origin of hydrogen bonding from the -NH- group (donor) and P[double bond, length as m-dash]O group (acceptor). The autocorrelation functions of PAA under different conditions (pure gel, gel with NaNO 3 , gel with formamide) are measured via DLS, and different characteristic times are obtained via the CONTIN method. Three different relaxation modes of the PAA gel, i.e., fast, intermediate and slow modes, are observed. The fast and intermediate modes show a diffusive behaviour (τ ∼ q -2 ), whereas the slow mode did not. When enough formamide is added into the PAA gel, the fast mode disappears; addition of enough salt (NaNO 3 ) leads to disappearance of the slow mode. The relationship between characteristic time and diffusion vector demonstrates that the different decorrelation modes consisted of two homodyne and two heterodyne components. Two single-exponential functions and two stretched exponential functions were used, and the different decorrelation modes of the PAA gel are expressed with a non-linear function, which fits the autocorrelation function very well. And the different decorrelation modes are also discussed. DWS results in the high-frequency region not only demonstrate the formation of a PAA gel network but also indicate that the semiflexible chains of PAA are due to electrostatic interaction. The DWS results at different time scales are analyzed by applying the de Gennes' reptation model.