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Titania coated manganese ferrite nanocomposite for removal of copper and lead ions from wastewater: preparation, characterization and adsorption studies
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Thick active‐layer organic solar cells
Abstract
Organic solar cells (OSCs) present a promising renewable energy technology due to their cost-effectiveness, adaptability, and lightweight nature. The advent of non-fullerene acceptors has further boosted their significance, allowing for power conversion efficiencies that surpass 19% even with an active layer thickness of about 100 nm. However, in order to achieve large scale production, it is necessary to fabricate OSCs with thicker active layers exceeding 300 nm that are compatible with large-area printing techniques. Nevertheless, OSCs with thick active layers have inferior performance compared to those with thin active layers. To expedite the transition of OSCs from laboratory to industrial high-throughput manufacturing, considerable efforts have been made to comprehend the performance limitations of thick active-layer OSCs, develop novel photoactive materials that are high-performance and tolerant towards the thickness of the active layer, and optimize the morphology of the photoactive layer and device structure. This review aims to provide a comprehensive summary of the mechanisms that lead to efficiency loss in thick active-layer OSCs, the representative works on molecular design, and the optimization strategies for high-performance thick active-layer OSCs, and the remaining challenges that must be addressed.
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PY‐IT, an excellent polymer acceptor
Comprehensive Summary
All-Polymer solar cells (all-PSCs) have attracted considerable attention due to their inherent advantages over other types of organic solar cells, including superior optical and thermal stability, as well as exceptional mechanical durability. Recently, all-PSCs have experienced remarkable advancements in device performance thanks to the invention of polymerized small-molecule acceptors (PSMAs) since 2017. Among these PSMAs, PY-IT has garnered immense interest from the scientific community due to its exceptional performance in all-PSCs. In this review, we presented the design principles of PY-IT and discussed the various strategies employed in device engineering for PY-IT-based all-PSCs. These strategies include additive and interface engineering, layer-by-layer processing methods, meniscus-assisted coating methods, and ternary strategy. Furthermore, this review highlighted several novel polymeric donor materials that are paired with PY-IT to achieve efficient all-PSCs. Lastly, we summarized the inspiring strategies for further advancing all-PSCs based on PY-IT. These strategies aim to enhance the overall performance and stability of all-PSCs by exploring new materials, optimizing device architectures, and improving fabrication techniques. By leveraging these approaches, we anticipate significant progress in the development of all-PSCs and their potential as a viable renewable energy source.
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Bioactive hydrogels with pro‐coagulation effect for hemostasis
Comprehensive Summary
Hemostatic hydrogels are widely applied for wound management of damaged tissues, traumatic wounds, and surgical incisions. Some hydrogels composed of bioactive components, including fibrin and thrombin, showed great promise in the clinic due to their good pro-coagulation effect. Based on the expanding knowledge of cascade catalysis reaction of coagulation and emerging bioactive substances. Recently, massive bioactive hydrogels based on peptides, hemocoagulase, polyphosphate (polyP), etc., have been developed as hemostatic materials. Based on the coagulation process and mechanism, we summarize the role of reported bioactive hydrogels in hemostasis in this review. We conclude the key points in the coagulation process, including activation of coagulation factors, fibrinogen polymerization, etc., then discuss how to design bioactive hydrogels to accelerate coagulation targeted to these points. Finally, we conclude the progress and propose a perspective of bioactive hydrogels with a pro-coagulation effect for hemostasis.
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Radiation‐Induced Admicellar Graft Polymerization of 2‐Hydroxyethyl Methacrylate onto Polyvinylidene Fluoride Membranes Using an Electron Beam Accelerator
The graft polymerization of 2-hydroxyethyl methacrylate onto a polyvinylidene fluoride (PVDF) membrane by admicellar polymerization was accomplished using graft polymerization induced by radiation. Electron beam irradiation was applied to covalently activate more free radicals to graft the copolymer. The effect on the physicochemical properties of PVDF before and after modification was investigated.
Abstract
The efficiency of admicellar graft polymerization in functionalizing polyvinylidene fluoride (PVDF) membranes was explored. The effect of 2-hydroxyethyl methacrylate (HEMA) concentration and the absorbed dose was investigated using a simultaneous method of radiation-induced graft polymerization. The degree of grafting increased with raising the absorbed dose and HEMA concentration. The Fourier transform infrared (FTIR) peak for C–O stretch and the asymmetric and symmetric stretching of the C–O–C bridge, respectively, proved the presence of poly(2-hydroxyethyl methacrylate) (PHEMA) on the modified PVDF. As the grafting yield increased, rougher surfaces were observed. According to contact angle analysis, the grafted membrane with a higher grafting yield outperformed the low grafting yield membrane in terms of water flux and hydrophilicity.
A quantum chemical prediction on arc interruption capability of the dielectric gases
A priori quantum chemical model based on the electrostatic potential surfaces has been developed to predict the arc interruption capability of the dielectric gases straightforwardly by electronic descriptors. In terms of the rate of rise of the recovery voltage, the structure–activity relationship model is viable for the virtual screening of novel arc-quenching replacement gases for SF6, which is superior to the routine fluid magneto-hydrodynamic model.
Abstract
The use of sulfur hexafluoride (SF6) as an electrical insulator and arc-quenching gas in high-voltage equipment raises serious environmental concerns. The search of a replacement gas for SF6 is hindered by a priori assessment on its interruption performance. The routine fluid or mathematic magneto-hydrodynamic models for arc burning and extinguishing are too complex to be practical for virtual screening. Herein a state-of-the-art quantum chemical model to predict the interruption capability of the dielectric gases straightforwardly has been established in terms of the rate of rise of the recovery voltage (RRRV). On the basis of the molecular electrostatic potentials, five sets of descriptors, including the global statistical parameters vσ2$$ {v\sigma}^2 $$ and Π$$ \Pi $$, the site-specific parameter ΔV s, the total positive surface area A s +, augmented with the product of polarizability and dipole moment αμ, were optimized to reveal the inherent mechanisms for interruption and thus a viable structure–activity relationship mode for RRRV has been developed with the correlation coefficient 0.975. Theoretical RRRV relative to SF6 = 100 for all the known dielectric gases are in good agreement with the experimental data by a mean absolute deviation of 3.6. Accordingly, the perfluorinated cycloalkenes and alkynes, in particular, 1,3,3,3-tetrafluoropropyne, are found to be the promising candidates as the replacement dielectric gases for SF6.
Highly Efficient Base Catalyzed N‐alkylation of Amines with Alcohols and β‐Alkylation of Secondary Alcohols with Primary Alcohols
Here we report that two very important catalytic transformations i. e., N-alkylation of amines with alcohols and β-alkylation of secondary alcohols with primary alcohols that is generally carried out with transition metal-based catalysts can be performed with a catalytic amount of base under air in a closed vessel without using transition metals or any other additives generating only water as byproduct.
Abstract
Borrowing hydrogen (BH) reactions are very useful for the sustainable synthesis of C−C and C−N bonds. They generally operate with transition metal-based catalysts along with stoichiometric/catalytic amounts of added base. Here we report that two catalytic transformations, generally carried out with the BH methodology, i. e. N-alkylation of amines with alcohols and β-alkylation of secondary alcohols with primary alcohols, can be performed very effectively with just catalytic amounts of base under air without using any transition metal-based catalyst. The mechanism is proposed to be based on air oxidation of the alcohol to aldehyde followed by condensation to an unsaturated intermediate which undergoes transfer hydrogenation with alcohol to the product.
Photoinduced Oxygen Atom Transfer to α‐Pinene and R‐Carvone using a Dioxo‐Molybdenum (VI) Complex Incorporated within a Modified UiO‐67 (Zr/Ti) MOF
Photoinduced oxygen atom transfer to α-pinene and R-carvone using a dioxo-molybdenum (VI) complex incorporated within a modified UiO-67 (Zr/Ti) MOF was studied. Organometallic frameworks (MOFs) are an alternative support to heterogenize the molybdenum dioxo complex [MoO2Ln2], which catalyzes the Oxygen Atom Transfer (OAT). UiO-67 is a microporous material that allows the formation of the dioxo-Mo complex anchored to the 5,5′-dicarboxylate-2,2′-bipyridine (bpydc) ligand to achieve a variable number of dioxo-Mo units in the network. The MOF UiO-67 allows a post-synthetic ion exchange of Zr by Ti, modifying the optical properties that facilitate the use of UV light in the OAT reaction. The materials prepared are highly selective (100 %) for the epoxidation of α-pinene and R-carvone using O2 as an oxidant through a photoinduced oxygen atom transfer (OAT) process. The dioxo-Mo complex anchored on the UiO-67 (Zr/Ti) MOF during the photoinduced TAO process towards the monoterpenes forms the MoIV reduced unit, which interacts with O2 to regenerate of the active catalytic MoVI unit, and to continue the catalytic cycle of the oxygen atom transfer.
Abstract
We report a highly selective (100 %) epoxidation of α-pinene and R-carvone using an oxygen atom transfer (OAT) reaction facilitated by a dioxo-Mo complex (Mo(VI)O2Cl2Ln) incorporated into the ligand 5,5’-dicarboxylate-2,2’-bipyridine (bpydc) within a Metal-Organic Framework (MOF) type UiO-67. Photo-stimulated (350 nm) OAT reaction was carried out with oxygen molecular used as the oxidant for 10 h. UiO-67 was synthesized with a mixture of the ligands 2,2′-biphenyl-5,5′-dicarboxylate (bpdc) and 2,2-bipyridine-5,5-dicarboxylate (bpydc) in different molar ratios (67 : 33, 50 : 50, 70 : 30, 0 : 100 bpdc : bpydc) to promote a higher presence of catalytic sites, i. e., the dioxo-Mo complex units. Furthermore, a post-synthetic exchange of Zr for Ti, between 64 : 36 to 78 : 22 Ti : Zr molar ratio, was performed to improve the optical properties of the MOF and promote the photoinduced OAT reaction. The Catalytic system was characterized by FTIR, XRD, 1H NMR, XPS, TGA, N2 adsorption/desorption and UV-Vis-DR. The amount of the epoxide monoterpene is proportional to the number of the dioxomolybdenum(VI) units (MoO2) incorporated in the UiO-67 (Zr/Ti), and the OAT reaction selectivity is due to the absence of the oxygen radicals in the medium of reaction. Besides, The Mo complex exhibited excellent stability after five cycles of use.
Relativistic adapted Gaussian basis sets free of variational prolapse of small and medium size for cesium through radon
The most compact relativistic prolapse-free (RPF) Gaussian basis sets ever seen are developed here for cesium through radon, providing small- (SRPF) and medium-size (MRPF) alternatives. The largest errors of these basis sets are consistent with the expected quality level. Soon, these new basis sets should be applied in electronic structure calculations of larger molecular systems with a lower computational cost.
Abstract
Relativistic adapted Gaussian basis sets of small and medium sizes are presented in this study for all elements from cesium to radon, including some alternative electron configurations. Both basis sets are made free of variational prolapse, being developed by means of a polynomial version of the generator coordinate Dirac–Fock method. In addition, these sets were designed to be promptly used with two popular finite nuclear models, uniform sphere and Gaussian nuclei. The largest basis set errors found with the uniform sphere nucleus are 27.3 and 10.6 mHartree, respectively, for the small- and medium-size sets. The largest basis set errors obtained with the Gaussian nuclear model are smaller, reaching 23.2 and 7.1 mHartree for the small- and medium-size sets, respectively. Soon, these basis sets will be augmented with polarization functions to be properly used in molecular calculations.