Formation of Microporous Poly Acrylonitrile-Co-Methyl Acrylate Membrane via Thermally Induced Phase Separation for Immiscible Oil/Water Separation.

An interconnected sponge structure and porous surface poly (acrylonitrile-co-methyl acrylate) (P(AN-MA)) microfiltration membranes (MF) were fabricated via thermally induced phase separation (TIPS) by using caprolactam (CPL), and acetamide (AC) as the mixed diluent. When the ternary system was composed of 15 wt.% P(AN-MA), 90 wt.% CPL, and 10 wt.% AC and formed in a 25 °C air bath, the membrane exhibited the highest water flux of 8107 L/m2·h. The P(AN-MA) membrane contained hydrophobic groups (-COOCH3) and hydrophilic groups (-CN), leading it to exhibit oleophobic properties underwater and hydrophobic properties in oil. The membrane demonstrates efficient separation of immiscible oil/water mixtures. The pure water flux of the petroleum ether/water mixture measured 870 L/m2·h, and the pure oil flux of the petroleum tetrachloride/water mixture measured 1230 L/m2·h under the influence of gravity. Additionally, the recovery efficiency of diluents through recrystallization was 85.3%, significantly reducing potential pollution and production costs.

Polybrominated diphenyl ethers in dust, hair and urine: Exposure, excretion.

Polybrominated diphenyl ethers (PBDEs) have been detected in various environmental media and human tissues. PBDEs concentrations in dust from college buildings and homes and in paired hair and urine samples from students were determined. This is of great significance to explore the accumulation and excretion patterns of PBDEs in the human body. The median PBDEs concentrations in the dust (College: 84.59 ng/g; Home: 170.32 ng/g) and hair (undergraduate: 6.16 ng/g; Home: 3.25 ng/g) samples were generally lower than were found in the majority of previous studies. The PBDEs concentrations in the hair and urine samples were subjected to principal component analysis, and the results combined with the PBDEs detection rates confirmed that hair is a useful non-invasive sampling medium for assessing PBDEs exposure and the risks posed. Body mass indices (BMIs) were used to divide students who had not been exposed to large amounts of PBDEs into groups. Body fat percentage is an important factor affecting the accumulation of PBDE in the human body. Environmental factors were found to affect the PBDEs concentrations in the hair and urine samples less for normal-weight students (BMI≤24) than overweight students (BMI>24). Short-term environmental changes to more readily affect the PBDEs concentrations in the tissues of the normal-weight than overweight students. PBDEs with seven or more bromine substituents were found not to be readily excreted in urine. Performing molecular docking simulations of the binding of isomers BDE-99 and BDE-100 to megalin. The binding energy was higher for BDE-100 and megalin than for BDE-99 and megalin, meaning BDE-99 would be more readily excreted than BDE-100.

Preparation of Elastic Macroporous Graphene Aerogel Based on Pickering Emulsion Method and Combination with ETPU for High Performance Piezoresistive Sensors.

High-performance pressure sensors provide the necessary conditions for smart shoe applications. In this paper, the elastic Macroporous Graphene Aerogel (MGA) was synthesized via the modified Hummers' method, and it was further combined with Expanded-Thermoplastic polyurethane (ETPU) particles to assemble MGA-ETPU flexible sensors. The MGA-ETPU has a low apparent density (3.02 mg/cm3), high conductivity (0.024 S/cm) and fast response time (50 ms). The MGA-ETPU has a large linear sensing range (0-10 kPa) and consists of two linear regions: the low-pressure region (0 to 8 kPa) and the high-pressure region (8 to 10 kPa), with sensitivities of 0.08 kPa-1, and 0.246 kPa-1, respectively. Mechanical test results show that the MGA-ETPU sensor showed 19% reduction in maximum stress after 400 loading-unloading compression cycles at 40% strain. Electrical performance tests showed that the resistance of MGA-ETPU sensor decreased by 12.5% when subjected to sudden compression at 82% strain and returned to its original state within 0.05 s. Compared to existing flexible sensors, the MGA-ETPU sensors offer excellent performance and several distinct advantages, including ease of fabrication, high sensitivity, fast response time, and good flexibility. These remarkable features make them ideally suited as flexible pressure sensors for smart shoes.

A simple and low-energy strategy for the separation of water and acetonitrile.

As acetonitrile is a widely used solvent for the chemical industry, the recovery of acetonitrile from acetonitrile wastewater is significant for both industrial cost reduction and environmental protection. In this article, a simple, low-energy, and low-cost strategy is proposed for the effective separation of acetonitrile from high-concentration acetonitrile wastewater. The approach is based on a sequential combination of two steps: salt-induced phase separation and hydrophobic filtration. The acetonitrile wastewater was first induced to split into two phases by salt, that is, the acetonitrile-rich phase and the water-rich phase, then the above two phases were poured into the hydrophobic filter paper funnel for the separation. It was shown that NaCl is a suitable salting-out reagent, and that hydrophobic filter papers-obtained from modification by butyltrichlorosilane and octyltrichlorosilane were the optimal choice for hydrophobic filtration. The salt-induced phase separation process is able to increase the volume fraction of acetonitrile in the acetonitrile-rich phase up to 92%. The acetonitrile-rich phase can pass through the hydrophobic filter paper, whereas the water-rich phase was intercepted. The hydrophobic filter paper retained strong hydrophobicity and high acetonitrile-separating capacity after 3 months storage, or upon immersion in acetonitrile-water mixtures for 12 h, or applied for 25 consecutive separations.

Review of Polymer-Based Composites for Electromagnetic Shielding Application.

The rapid advancement of electronic communication technology has greatly aided human productivity and quality of life, but it has also resulted in significant electromagnetic pollution issues. Traditional metals and alloys are often used for electromagnetic interference (EMI) shielding due to their excellent electrical conductivity. However, they have drawbacks such as being heavy, expensive, and having low corrosion resistance, which limits their application in electromagnetic shielding. Therefore, it is crucial to develop novel EMI shielding materials. Polymers, being highly flexible, corrosion-resistant, and possessing high specific strength, are frequently employed in electromagnetic shielding materials. In this review, we firstly introduce the basic theory of electromagnetic shielding. Then, we outline the processing methods and recent developments of polymer-based electromagnetic shielding composites, including uniform-, foam-, layered-, and segregated structures. Lastly, we present the challenges and prospects for the field, aiming to provide direction and inspiration for the study of polymer-based electromagnetic shielding composite materials.

High-Yield Production of Lignin-Derived Functional Carbon Nanosheet for Dye Adsorption.

In this article, we report the preparation of lignin-derived carbon nanosheet (L-CNS) by direct thermal treatment of lignin without activation operation and the functions of the L-CNS as an adsorbent for rhodamine dye. The L-CNSs are fabricated by freeze-drying (FD) methods of lignin followed by high-temperature carbonization. It is found that lower frozen temperature in FD or lower concentration of lignin aqueous solution renders L-CNSs' more porous morphology and higher specific surface area (SSA), allowing a promising application of the L-CNSs as an efficient adsorbent for organic pollutants. In particular, the alkaline hydroxide catalyst helps to increase the SSA of carbon products, leading to a further improved adsorption capacity. On the other hand, p-toluenesulfonic acid (TsOH) catalyzed pyrolysis, which dramatically increased the L-CNS product yield, and provided a high-yield approach for the production of pollutant absorbent.

Superhydrophobic Covalent Organic Frameworks Prepared via Pore Surface Modifications for Functional Coatings under Harsh Conditions.

Covalent organic frameworks (COFs) have been widely used in catalysis, energy storage, environmental protection, and separation. However, they require a long assembly period (∼3 days) and complex synthesis conditions; differences in water resistance have restricted their overall versatility. In this paper, the preparation of COF-DhaTab was optimized, and this process can be easily performed in air. Thus, it is feasible for the scale-up of COF-DhaTab in the near future. The superhydrophobic properties of COF-DhaTab (water contact angle, >150°) can be created by regulating the wettability of COF-DhaTab by grafting fluoride. When the grafting degree of fluoride increased to 4.32%, the water contact angle of COFs increased from 0° to more than 150°. The grafted COFs are termed COF-DhaTab fluoride (COF-DTF). The chemically modified COF-DhaTab maintains its original porosity and crystallinity. The superhydrophobic COF-DTF can be applied to various substrates, for example, foam, fabric, and glass. These all exhibit outstanding water repellency, self-healing, and excellent self-cleaning. Importantly, the coating maintains its original superhydrophobicity even under extremely acidic/basic conditions (pH = 1-14) and toward boiling water (100 °C). Furthermore, COF-DTF displays long-term stability and is easily scaled. It is a promising and practical candidate for hydrophobic modifications to various substrates.

Bioinspired Superwettable Covalent Organic Framework Nanofibrous Composite Membrane with a Spindle-Knotted Structure for Highly Efficient Oil/Water Emulsion Separation.

Covalent organic frameworks (COFs) have attracted broad interest in a number of fields including gas access, catalysis, and ionic adsorption. However, owing to the low stability in water, the application of COFs in the field of oil/water separation is extensively impeded. In this paper, we synthesized COF-DhaTab/polyacrylonitrile (PAN) nanofibrous composite membranes with a bioinspired spindle-knotted structure via a facile blending electrospinning method. The COF-DhaTab/PAN composite membrane shows prewetting-induced superoleophobicity under water and superhydrophobicity under oil. It possesses outstanding rejection ratio (>99.9%), excellent antifouling performance, and ultrahigh oil/water mixture flux up to 4229.29 L/m2h even though driven only by gravity. Specifically, an extraordinary oil contact angle under water (152.3°) and a satisfied water contact angle under oil (153.7°) were offered by the composite membrane. These are mainly attributed to the spindle-knotted structures induced by COFs. To the best of our knowledge, the application of COF/PAN composite membrane in the field of oil/water separation has never been reported. It is an innovative approach for oily wastewater treatment and oil purification.

Enhanced Thermal-to-Flexible Phase Change Materials Based on Cellulose/Modified Graphene Composites for Thermal Management of Solar Energy.

The applications of phase change materials (PCMs) in some practical circumstances are currently limited due to the constant strong rigidity, poor thermal conductivity, and low photoabsorption property. Therefore, the design of flexibility-enhanced, highly efficient PCMs is greatly desirable and challenging. In this work, novel PCM composites (CPmG-x) with stable forms and thermally induced flexibility were successfully prepared by grafting the comblike poly(hexadecyl acrylate) polymer (PA16, phase change working substance) onto a cellulose support by atom transfer radical polymerization (ATRP). Modified graphene (GN16) was incorporated into the synthesized material to enhance its enthalpy, thermal conductivity, and physical strength. The prepared CPmG-x composites exhibit excellent softness and flexibility after phase transition of PA16. The addition of GN16 increases the thermal conductivity and enthalpy of CPmG-x materials to 1.32 W m-1 K-1 (9 wt % GN16) and 103 J g-1 (5 wt % GN16), respectively. Assessments of the solar-to-thermal energy conversion and storage efficiencies indicate that CPmG-x composites possess great potential for use in thermal energy management applications and solar energy collection systems.

Simultaneous analysis of 2Cs, 25-NBOHs, 25-NBOMes and LSD in seized exhibits using liquid chromatography-tandem mass spectrometry: A targeted approach.

Blotter papers laced with lysergic acid diethylamide (LSD) have been abused traditionally for their hallucinogenic properties. In recent years, new psychedelic phenethylamines such as 2,5-dimethoxyphenethylamines (2C) and their N-benzylhydroxy (25-NBOH) and N-2-methoxybenzyl derivatives (25-NBOMe) have emerged in the illicit drugs market. Traditionally, gas chromatography-mass spectrometry (GC-MS) is regarded as the gold standard for illicit drugs analysis. However, with the emergence of new psychoactive substances (NPS) which are thermally labile (such as the 25-NBOH drugs which undergo thermal degradation to their respective 2C drugs), alternative non-thermal techniques have to be developed in order to prevent misidentification. In this study, a single, targeted, non-thermal analytical method using the liquid chromatography-tandem mass spectrometry (LC-MS/MS) to simultaneously identify these new phenethylamines and their derivatives was developed and validated. Twelve phenethylamines and their derivatives, as well as LSD were simultaneously analysed using the LC-MS/MS in a multiple reaction monitoring (MRM) detection mode. The method developed was validated and applied for the analysis of phenethylamines and their derivatives commonly found in seized exhibits such as blotter papers and Ecstasy tablets.

Homogeneous synthesis of cellulose acrylate-g-poly (n-alkyl acrylate) solid-solid phase change materials via free radical polymerization.

A novel solid-solid phase change materials, namely, cellulose acrylate-g-poly (n-alkyl acrylate) (CA-g-PAn) (n = 14, 16 and 18) were successfully synthesized by free radical polymerization in N, N-dimethylacetamide (DMAc). The successful grafting was confirmed by fourier transform infrared spectra (FT-IR) and nuclear magnetic resonance (NMR). The properties of the CA-g-PAn copolymers were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA). The phase change temperatures and the melting enthalpies of CA-g-PAn copolymers are in the range of 10.1-53.2 °C and 15-95 J/g, respectively. It can be adjusted by the contents of poly (n-alkyl acrylate) and the length of alkyl side-chain. The thermal resistant temperatures of CA-g-PA14, 16 and 18 copolymers are 308 °C, 292 °C and 273 °C, respectively. It show that all of grafting materials exhibit good thermal stability and shape stability. Therefore, it is expected to be applied in the cellulose-based thermos-regulating field.