Polymers
·
2023
·Vol. 15
·期 3
·720
·
IF 5
Jianglin Zhu,Xiaoming Luo,Xin Li
Aliphatic polycarbonate (APC) compounds are an important class of biodegradable materials with excellent biocompatibility, good biodegradability, and low toxicity, and the study of these compounds and their modification products aims to obtain biodegradable materials with better performance. In this context, the ring-opening polymerization (ROP) of trimethylene carbonate (TMC) from a low nucleophilic organic superbase of phosphazene (t-BuP4) as a catalyst and benzyl alcohol (BnOH) as an initiator at room temperature was carefully studied to prepare poly(trimethylene carbonate) (PTMC) which is one of the most studied APC.1H NMR and SEC measurements clearly demonstrate the presence of a benzyloxy group at theα-terminus of the obtained PTMC homopolymers while investigation of the polymerization kinetics confirms the controlled/living nature oft-BuP4-catalyzed ROP of TMC. On the basis of this, the block copolymerization of TMC andδ-valerolactone (VL)/ε-caprolactone (CL) was successfully carried out to give PTMC-b-PCL and PTMC-b-PVL copolymers. Furthermore, PTMC with terminal functionality was also prepared with the organocatalytic ROP of TMC through functional initiators. We believe that the present ROP system is a robust, highly efficient, and practical strategy for producing excellent biocompatible and biodegradable PTMC-based materials.Keywords:PTMC;t-BuP4;controlled/living nature;end functionality
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MACROMOLECULES
·
2023
·
IF 5.5
Yupo Xu,Lei Wang,Chuanshuang Chen,Pei Huang,Haojie Dai,Wenfeng Jiang,Yongfeng Zhou
Research on metal-free catalytic synthesis of polycaprolactone (PCL) is fueled by the many practical needs for biodegradable and biocompatible materials. In this regard, the pursuit of effective and economical catalysts as well as precise control over the polymerization has become the main challenge. Herein, we report a living cationic ring-opening polymerization of ε-caprolactone catalyzed by a safe, inexpensive, and metal-free Lewis acid of trityl tetrafluoroborate. The polymerization is initiated by alcohol or water, which is corroborated by the presence of initiator segments at the chain ends of PCL polymers via 1H NMR and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Kinetic experiments show that polymerization is a first-order reaction to monomers. This result, together with the predictable molar mass, narrow molar-mass dispersity, and controllable chain growth and extension, confirms the synthesis to be a living polymerization. This work expands the catalytic toolbox of PCL synthesis and represents a rare example of cationic living polymerization of ε-caprolactone catalyzed by Lewis acids.
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ACS Applied Nano Materials
·
2022
·
IF 6.14
Yaya Fang,Weiwei Lu,Peng Xu,Kaisheng Yao,Jun Zhang,Xuefeng Wei,Shuge Peng,Kunpeng Sun
In this work, we propose a plasmon-mediated method to activate oxygen for oxidizing benzyl alcohols to aldehydes. First, hollow Ag@Pd core–shell nanoparticles were prepared and characterized and afterward explored for selective oxidation of benzyl alcohols under visible light illumination. Then, electron paramagnetic resonance analysis and spectroscopic measurements suggested that the main active species responsible for the selective oxidation was 1O2, which was subsequently proved to be generated from the transformation of superoxide radicals •O2–. The light illumination and the presence of a Pd shell were the prerequisites for the successful generation of •O2– and 1O2. Furthermore, the wavelength-dependent performance of Ag@Pd verified the plasmon-mediated nature of these core–shell-type nanocatalysts. Finally, a plausible mechanism of plasmonic activation of oxygen and selective oxidation of benzyl alcohols on Ag@Pd was proposed. Our research opens a green and sustainable way to activate molecular O2 into 1O2 for selective oxidation.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
·
IF 5.518
Bin Sun,Fengfei Chen,Hualin Lin,Yuan Xue,Sheng Han
The poor cold flow properties (CFPs) are the main factors that hinder the utilization and popularization of diesel fuel. Cold flow improvers (CFIs) are usually add to diesel fuel to compensate for liquidity problems at low temperatures. In this study, monomers with different functional groups were used to synthesize methyl benzyl acrylate-co-hexadecene-maleic anhydride (MB-HD-MA) terpolymers with different mole ratios through free radical polymerization , and then the terpolymers were modified with tetradecanol to obtain comb type terpolymers (MB-HD-MA-C14). The structure of MB-HD-MA and MB-HD-MA-C14 were characterized by Fourier transform infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance Hydrogen spectra (1 H NMR). Adding CFIs to diesel fuel effectively improved the CFPs, 1000 ppm MB-HD-MA-C14 (3:1:4) presented the best depression effects on cold filter plugging point (CFPP) and solid point (SP) by 12 °C and 21 °C, respectively. The results showed that the non-polar and polar components in CFIs exert synergistic effect at an optimal ratio to improve CFPs with greater efficiency. Moreover, rheology analysis and polarizing optical microscopy showed that MB-HD-MA-C14 (3:1:4) can improve the rheological properties by reducing dynamic viscosity and improve the crystallization behavior of wax crystals at low temperature by decreasing the size and modifying the morphology of the wax crystals.
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Insects
·
2023
·Vol. 14
·期 12
·930
·
IF 3
Jianjun Cheng,Jiawei Gui,Xiaoming Yao,Hong Zhao,Yujie Zhou,Yongjun Du
Simple SummaryThe rice leaf roller,Cnaphalocrocis medinalis,is a migratory insect pest threatening rice production. Monitoring its population dynamics is a critical component of the integrated management system for this pest. Plant odor-trapping has been used as a tool for population monitoring. However, there is a lack of knowledge on the molecular mechanism by which theC. medinalismoth recognizes the plant odor. In the present study, we amplified 12 odor receptor genes and tested differential expression of these genes in male and female moths ofC. medinalis. We identified the function of three olfactory receptor genes inC. medinalis.CmedOR31 was a specific receptor for geraniol, and CmedOR32 was a broad-spectrum OR receptor that responds to both foliar odor and floral scent. The ligands of CmedOR1 were linalool, phenethyl alcohol, 2-phenylethanol, and phenylacetaldehyde. CmedOR1 belonged to a unique conserved OR lineage that strongly responded to phenylacetaldehyde in the evolution ofGlossataspecies, and the OR1 expression inC. medinalisantennae was significantly higher in females than in males. CmedOR1 was the odor receptor forC. medinalisadults to locate food sources.AbstractCnaphalocrocis medinalis(Lepidoptera: Crambidae) is a migratory insect pest on rice crops. The migratoryC. medinalispopulation in a particular location may be immigrants, local populations, emigrants, or a mix of these. Immigrants are strongly attracted to plant odor. We conducted research to identify the olfactory receptors in a floral scent mixture that is strongly attractive toC. medinalis. Through gene cloning, 12 olfactory receptor (OR) genes were amplified and expressed in Xenopus oocytes in vitro, and three of them were found to be responsive to plant foliar and floral volatiles. These were CmedOR31, a specific receptor for geraniol; CmedOR32, a broad-spectrum OR gene that responded to both foliar and floral odors; and CmedOR1, which strongly responded to 10−4M phenylacetaldehyde. The electrophysiological response to phenylacetaldehyde was extremely high, with a current of 3200 ± 86 nA and an extremely high sensitivity. We compared the phylogenetic tree and sequence similarity of CmedOR genes and found that CmedOR1 belonged to a uniquely conserved OR pedigree in the evolution ofGlossataspecies, and the ORs of this pedigree strongly responded to phenylacetaldehyde. The expression of OR1 was significantly higher in the females than in the males. Localization of CmedOR1 in the antennae ofC. medinalisby fluorescence in situ hybridization showed that CmedOR1 was expressed in both males and females. CmedOR1 may be an odor receptor used by females to locate food sources. The function of these ORs and their role in pest monitoring were discussed.Keywords:functional identification;Cnaphalocrocis medinalis;floral odorant;olfactory receptor
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MACROMOLECULAR RAPID COMMUNICATIONS
·
2023
·Vol. 44
·期 24
·2300371
·
IF 4.6
Shikun Zhao,Shun Gong,Biao Zhao,Like Hou,Lurong Zhang,Qing Hu,Kai Pan
Polyamide 56 (PA56) has gained significant attention in the academic field due to its remarkable mechanical and thermal properties as a highly efficient and versatile biobased material. Its superior moisture absorption property also makes it a unique advantage in the realm of fiber textiles. However, despite extensive investigations on PA56's molecular and aggregate state structure, as well as processing modifications, little attention has been paid to its polymerization mechanism. Herein, the influence of temperature and time on PA56's polycondensation reaction is detailed studied by end-group titration and carbon nuclear magnetic resonance (NMR) techniques. The reaction kinetics equations for the pre-polymerization and vacuum melt-polymerization stages of PA56 are established, and possible side reactions during the polycondensation process are analyzed. By optimizing the reaction process based on kinetic characteristics, PA56 resin with superior comprehensive properties (melting temperature of 252.6 °C, degradation temperature of 371.6 °C, and tensile strength of 75 MPa) is obtained. The findings provide theoretical support for the industrial production of high-quality biobased PA56.
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Small
·
2023
·
IF 13.3
Zhihao Chen,Malik Zeeshan Shahid,Xinyan Jiang,Meng Zhang,Danrui Pan,Hongpeng Xu,Guocan Jiang,Jin Wang,Zhengquan Li
Halide perovskites exhibit outstanding optoelectronic properties, which make them an ideal choice for photocatalytic CO 2 reduction and benzyl alcohol (BA) oxidation. Nevertheless, the simultaneous realization of the above redox coupling reactions on halide perovskites remains a great challenge, as it requires distinct catalytic sites for different target reactions. Herein, the catalytic sites of Cs 2 AgBiCl 6 (CABC) are regulated by doping Fe for efficient coupling of photocatalytic CO 2 reduction and BA oxidation. The Fe-doped CABC (Fe: CABC) exhibits an enhanced visible-light response and effective charge separation. Experimental results and theoretical calculations reveal a synergistic interplay between Bi and Fe sites, where the Bi and Fe sites have lower activation energies toward CO 2 reduction and BA oxidation. Further investigations demonstrate that electrons and holes prefer to accumulate at the Bi site and Fe site under light irradiation, respectively, which creates favorable conditions for facilitating CO 2 reduction and BA oxidation. The resultant Fe: CABC achieves a high photocatalytic performance toward CO (18.5 µmol g −1 h −1 ) and BD (1.1 mmol g −1 h −1 ) generation, which surpasses most of the state-of-the-art halide photocatalysts. This work demonstrates a facile strategy for regulating the catalytic site for redox coupling reactions, which will pave a new way for designing halide perovskites for photocatalysis.
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PROGRESS IN ORGANIC COATINGS
·
2023
·
IF 6.6
Xinlin Li,Zhe Zhao,Yan Liu,Yanju Liu,Jinsong Leng
Outdoor equipment can suffer from functional failure in winter due to ice accumulation. Although functional materials are widely recognized as promising candidates for anti-icing and de-icing applications, ice inevitably accretes on surfaces at extremely low temperatures and high humidity. If surfaces display reversible superhydrophobic and slippery performance, similar to Lotus leaves and fish skin, it will significantly improve the anti-icing and de-icing performance. This study proposes a novel type of multifunctional coating that could smartly reverse between superhydrophobic and slippery properties on demand. The superhydrophobic coatings with diverse morphologies were obtained by employing different sizes and shapes of nanoparticles . Due to the low adhesion and photothermal properties, the superhydrophobic samples presented good freezing rain prevention and snow-melting performances by outdoor tests in winter. The samples with slippery surfaces were produced by infusing dodecane on the as-prepared superhydrophobic surface. Both the superhydrophobic and slippery surfaces can effectively propel the water droplets, prolong the freezing time and enhance ice removal performance in an extremely cold environment. Therefore, the coated samples with bi-stable states (i.e., superhydrophobic and slippery states) were successfully achieved with the potential to be widely applied under different service environments. This facile strategy will provide the possibility for developing novel materials with smart reversible wettability for anti-icing and de-icing applications.
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NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 32
·15036-15046
·
IF 3.3
Fengwei Zhang,Peihao Liu,Jingjing Li,Hefang Guo,Han Zhang,Zehui Zhang,Zhengping Dong
Designing and synthesizing highly efficient non-noble metal-based catalysts with uniform active sites provide a powerful platform for recognizing real active sites and understanding catalytic reaction mechanisms. Herein, we prepared a series of N-doped graphene-like carbon (NG) intercalated Co-based single/dual-atom catalysts via a hard template-assisted spatial confinement strategy. Comprehensive characterization studies confirmed the atomically dispersed cobalt single atom active sites. The obtained Co SACs@NG-800-50 catalyst exhibits satisfying activity and selectivity for oxidative esterification of benzyl alcohol and other investigated alcohols under mild conditions. The catalyst can effectively activate O2 to generate ˙O2− active species through abundant CoN3 active sites, thus promoting the smooth progress of oxidative esterification of aromatic alcohols. Moreover, the catalyst displays excellent structural stability and recycling durability even after 6 reactions.
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JOURNAL OF POLYMER SCIENCE
·
2023
·Vol. 62
·期 5
·870-879
·
IF 3.4
Yingdong Wu,Lu Bai,Junping Zheng
In recent years, as an emerging dynamic bonding, silyl ether linkages have been concerned and applied. However, the reprocessability of vitrimers based on it is far from satisfactory because of the inactive dynamic exchange reaction. At the same time, the mechanical properties of polysiloxane elastomers are poor because of the high flexibility of polysiloxane molecular chains and weak intermolecular forces. Herein, we have successfully synthesized a PDMS elastomer incorporating Zn(II)-amine coordination bonds as sacrificial units, which are crosslinked through dynamic silyl ether linkages. Importantly, the presence of Zn ions promotes the exchange between the silyl ether linkages and hydroxyl groups. The elastomers exhibited excellent mechanical properties (35 times improvement in toughness) and outstanding reprocessability. The mechanical property recovery of the PDMS elastomers reached approximately 90% after four reprocessing cycles. Meanwhile, small-molecule simulation experiments were conducted to verify the significant catalytic effect of Zn (II) ions as Lewis acid catalysts on the exchange reaction of silyl ether linkages and hydroxyl groups. In a word, this work provides a facile strategy to simultaneously enhance the mechanical properties and reprocessing performance of silyl ether-linked polysiloxane elastomers. Graphical
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INORGANIC CHEMISTRY
·
2023
·
IF 4.6
Hongjing Wang,Yuqin Liang,Songliang Liu,Hongjie Yu,Kai Deng,You Xu,Xiaonian Li,Ziqiang Wang,Liang Wang
The research on high-efficiency two-dimensional (2D) catalytic materials for the small-molecule oxidation-assisted hydrogen evolution reaction (HER) is prospective for efficient hydrogen production. Herein, we report heterostructured Pt/Rh metallene with Pt nanoparticles (NPs) uniformly anchored on Rh metallene for the HER and ethylene glycol oxidation reaction (EGOR). The ultrathin sheet structure of the Pt/Rh metallene offers high surface areas and sufficient active sites. More importantly, the Pt/Rh heterostructure can optimize catalytic active centers and adjust electronic structure. Thus, Pt/Rh metallene exhibits superior electrocatalytic HER activity with a low overpotential of 28 mV in 1 M KOH at 10 mA cm–2 and EGOR activity with a specific activity of 8.39 mA cm–2 in 1 M KOH with 3 M EG, along with outstanding CO tolerance. In a two-electrode system, Pt/Rh metallene requires a low potential of 0.51 V for stable and efficient hydrogen production at 10 mA cm–2 in 1 M KOH + 3 M EG, with the simultaneous production of high-value-added products. The job proposes an attractive strategy for the synthesis of 0D/2D metallene toward simultaneous energy-saving hydrogen production and chemical update.
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FOOD CHEMISTRY
·
2023
·
IF 8.8
Meiqin Li,Zhihui Feng,Fang Wang,Jianxin Chen,Jie Fan,Jieqiong Wang,Zhengquan Liu,Junfeng Yin
There is a huge demand for brewing water in tea consumption, and the sensory flavor of tea infusion is significantly affected by the water used for brewing. To investigate the impact of brewing water on the aroma of tea infusions made from Camelia senensis , the three tea infusions of green, oolong and black tea brewed by six different drinking waters were analyzed by sensory evaluation, solid-phase microextraction, gas chromatography–mass spectrometry, and chemometrics. Brewing water with high pH values (>8.10) and high TDS content (>140 ppm) resulted in a lower overall aroma acceptability for tea infusion, where HCO 3 – , Ca 2+ and Mg 2+ were key influencing ions. A total of 86, 106, and 131 volatiles were identified in green, oolong and black tea infusions, respectively, which were strongly influenced by six different brands of waters. Decanal, dimethyl sulfide, β-ionone and linalool were potent volatiles in tea aroma changes caused by brewing water.
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危险品化学品经营许可证（带存储）