Data-driven discovery of a universal indicator for metallic glass forming ability.

Despite the importance of glass forming ability as a major alloy characteristic, it is poorly understood and its quantification has been experimentally laborious and computationally challenging. Here, we uncover that the glass forming ability of an alloy is represented in its amorphous structure far away from equilibrium, which can be exposed by conventional X-ray diffraction. Specifically, we fabricated roughly 5,700 alloys from 12 alloy systems and characterized the full-width at half-maximum, Δq, of the first diffraction peak in the X-ray diffraction pattern. A strong correlation between high glass forming ability and a large Δq was found. This correlation indicates that a large dispersion of structural units comprising the amorphous structure is the universal indicator for high metallic glass formation. When paired with combinatorial synthesis, the correlation enhances throughput by up to 100 times compared to today's state-of-the-art combinatorial methods and will facilitate the discovery of bulk metallic glasses.

Polyethyleneimine-functionalized magnetic sugarcane bagasse cellulose film for the efficient adsorption of ibuprofen.

Polyethyleneimine-modified magnetic sugarcane bagasse cellulose film (P-SBC/Fe3O4 film) was simply fabricated for the removal of ibuprofen (IBP), a typical emerging organic contaminant. The P-SBC/Fe3O4 film exhibited an equilibrium adsorption amount of 370.52 mg/g for IBP and a corresponding removal efficiency of 92.63 % under following adsorption conditions: 318 K, pH 4, and 0.25 mg/mL dosage. Thermodynamic studies indicated that adsorption of IBP on the P-SBC/Fe3O4 film was spontaneous (∆G < 0) and endothermic (∆H > 0). The adsorption data conformed to the Freundlich isotherm model and multilayer adsorption model (two layers), and an average of 3-4 active sites on the P-SBC/Fe3O4 film share an IBP molecule. Both the EDR-IDR and AOAS models vividly described the dynamic characteristics of adsorption process. Model fitting results, theoretical calculations, and comprehensive characterization revealed that adsorption is driven by electrostatic interactions between the primary amine of P-SBC/Fe3O4 film and the carboxyl group of IBP molecule, while other weak interactions are also non-ignorable. Furthermore, quantitative calculations based on density functional theory (DFT) underscored the importance of PEI functionalization. In conclusion, P-SBC/Fe3O4 film is an environmentally friendly and cost-effective adsorbent with significant potential for effectively removing IBP, while maintaining its efficacy over multiple cycles.

High capacity and selective adsorption of Congo red by cellulose-based aerogel with mesoporous structure: Adsorption properties and statistical data simulation.

Large quantities of organic dyes are discharged into the environment, causing serious damage to the ecosystem. Therefore, it is urgent to develop inexpensive adsorbents to remove organic dyes. A novel cellulose-based aerogel (MPPA) with 3D porous structure was prepared by using cassava residue (cellulose) as basic construction blocks, doping ferroferric oxide (Fe3O4) for magnetic separation, and applying polyethyleneimine (PEI) as functional material for highly efficient and selective capture of Congo red (CR). MPPA exhibited porous network structure, numerous active capture sites, nontoxicity, high hydrophilicity, and excellent thermal stability. MPPA showed superior adsorption property for CR, with an equilibrium adsorption capacity of 2018.14 mg/g, and still had an adsorption property of 1189.31 mg/g after five recycling procedures. In addition, MPPA has excellent selectivity for CR in four binary dye systems. The adsorption behavior of MPPA on CR was further explored using a multilayer adsorption model, EDR-IDR hybrid model and AOAS model. Electrostatic potential and independent gradient models were used to further verify the possible interaction between MPPA and CR molecules. In conclusion, MPPA is a promising adsorbent in the field of treating anionic dyes.

(3-Chloro-2-hydroxypropyl) trimethylammonium chloride and polyethyleneimine co-modified pomelo peel cellulose-derived aerogel for remelt syrup decolorization in sugar refining.

The crucial need for quality refined sugar has led to the development of advanced adsorbents, with a focus on the decolorization of remelt syrup. In this study, (3-chloro-2-hydroxypropyl) trimethylammonium chloride and polyethyleneimine co-modified pomelo peel cellulose-derived aerogel (CP-PPA) was fabricated, and synthetic melanoidins were used as model colorants of remelt syrup to evaluate the validity and practicality of CP-PPA for eliminating colored impurities. Integrating abundant amine-functionalized groups (quaternary ammonium and protonated amine) within the pomelo peel-derived aerogel directionally captured electronegative melanoidins via electrostatic interactions. Furthermore, the active sites, types, and relative strength of the weak interactions between CP-PPA and melanoidins were determined using density functional theory simulations. CP-PPA exhibited an excellent equilibration adsorbing capacity for capturing melanoidins of 749.51 mg/g, and a removal efficiency of 93.69 %. Additionally, the adsorption mechanism was thoroughly examined in an effort to improve the economy of the sugar refinement industry.

Hyperbranched polyethyleneimine-functionalised chitosan aerogel for highly efficient removal of melanoidins from wastewater.

Melanoidins are hazardous dark-coloured substances contained in molasses-based distillery wastewater. Adsorption is an effective approach to eliminate melanoidins from wastewater. However, melanoidin adsorption capacities of available adsorbents are unsatisfactory, which seriously limits their practical application. A hyperbranched polyethyleneimine-functionalised chitosan aerogel (HPCA) was fabricated as an effective adsorbent for melanoidin scavenging. HPCA demonstrated superior melanoidin adsorption efficiency because of its high specific surface area, abundant amino functional groups, and high hydrophilicity. Melanoidin removal rate of HPCA was 94.95%, which remained at 91.45% after 5 cycles. Notably, using the Langmuir isothermal model, the maximum melanoidin adsorption capacity of HPCA was determined to be 868.36 mg/g, surpassing those of most of previously reported adsorbents. Toxicity experiments indicated that HPCA can be considered a safe adsorbent with excellent biocompatibility that hardly threatens aquatic organisms. The efficient melanoidin removal of HPCA was attributed to electrostatic attraction, H-bonding, and van der Waals force. However, the adsorption might be predominantly controlled by electrovalent interaction between protonated amino groups of HPCA and carboxyl/carboxylate groups of melanoidins. Two novel models, namely, external diffusion resistance-internal diffusion resistance mixed model and adsorption on active site model, were employed to describe the dynamic mass transfer characteristics of melanoidin adsorption by HPCA.

Effect of an extrafibrillar dentin demineralization strategy on the durability of the resin-dentin bond.

OBJECTIVES: This study aimed to evaluate the potential of the extrafibrillar dentin demineralization strategy on the long-term dentin bond strength of an etch-and-rinse adhesive. METHODS: A water-soluble glycol chitosan-EDTA (GCE), a chelating conditioner, was synthesized and subjected to size-exclusion dialysis to obtain molecules >40 kDa. The conjugation of EDTA to glycol chitosan was analyzed by Fourier transform infrared (FTIR) spectroscopy. Mid-coronal dentin surfaces of 80 teeth were either acid-etched with 35% phosphoric acid or conditioned with 25 mg/mL GCE (n = 40) and thoroughly water-sprayed before applying the etch-and-rinse adhesive Adper Single Bond Plus and placing Z250 composite resin (3 M Oral Care; St Paul, MN, USA). Resin-bonded specimens were prepared into beams with a cross-sectional area of about 0.9 mm2 vertically through the resin-dentin interfaces before the microtensile bond strengths (MTBS) were determined immediately or after 3, 6, or 12 months of water storage. The resin-dentin interfaces were analyzed using transmission electron microscopy (TEM). The MTBS data were analyzed using two-way ANOVA followed by the LSD post-hoc multiple comparisons (P < 0.05). RESULTS: FTIR spectra showed that EDTA was successfully conjugated to glycol chitosan. The phosphoric acid-etching group and GCE-conditioning group showed similar bond strength values after 24 h of water storage. The bond strength of the phosphoric acid-etching group after 12-month water aging was significantly reduced from 51.61 ± 3.30 MPa to 38.57 ± 4.81 MPa, while the bond strength of the GCE-conditioning group was not significantly reduced from 50.28 ± 3.62 MPa to 46.40 ± 4.71 MPa.The degradation of the hybrid layer could be detected in the phosphoric acid-etching group after 12 months of water aging, but not in the GCE-conditioning group. CONCLUSION: The extrafibrillar dentin demineralization strategy using GCE conditioner could defy the hybrid layer degradation of the dentin bond after 12 months of water aging and enhance the dentin bond durability of the etch-and-rinse adhesive Adper Single Bond Plus.

A homochiral Cu(i) coordination polymer based on achiral precursors and its photocatalytic properties.

A homochiral three-dimensional framework material, [Cu(7)(4-bpt)(6)(CN)(H(2)O)] (1) (4-bpt = 3,5-bis(4-pyridyl)-1,2,4-triazole), has been successfully synthesized by solvothermal reaction, which is generated through an unusual spontaneous asymmetrical crystallization from achiral precursors, and its photocatalytic properties in degradation of organic dyes are also investigated.