ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2021
·
IF 9.028
Huijun Su,Shaobo Shi,Ming Zhu,Jianhua Li,Guanyong Su
Liquid crystal monomers (LCMs) have been proposed to be persistent, bioaccumulative, and toxic (PBT) substances; however, there is a dearth of information regarding their occurrence in sediment samples. Here, an analytical method was developed for the quantitative determination of LCMs in sediment samples, and n = 76 sediment samples were collected and analyzed to determine accurate concentrations of LCMs. Our results indicated that the developed pretreatment procedure was applicable for the determination of LCM concentrations in sediments. We observed that LCMs were detected in 75 out of the 76 sediment samples, and 23, 18, and 14 out of the 39 target LCMs were quantified in at least one of the analyzed sediments from rivers around LCM or liquid crystal device (LCD) manufacturers, Taihu Lake, and rivers around e-waste recycling sites, respectively. The LCMs in the samples from rivers around LCM/LCD manufacturers exhibited the greatest mean concentrations of 26.1 ng/g dry weight (dw), followed by those from e-waste recycling site areas (1.15 ng/g dw) and Taihu Lake (0.076 ng/g dw). Collectively, this study provided the first analytical method that was able to quantify the concentrations of LCMs in sediment samples and provided the first evidence for the occurrence of LCMs in sediment samples.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 138
·期 6
·49791
·
IF 2.52
Chenggong Li,Ying Li,Changdan Gong,Kunpeng Ruan,Xiao Zhong,Pan Pan,Chao Liu,Junwei Gu,Xuetao Shi
The thermal conductivity of bulk polymers is usually very low, which is due to the amorphous domains where chains are randomly entangled, improving the degree of the chain alignment and forming a continuous thermal conduction network are expected to enhance the thermal conductivity. A series of liquid crystalline monomer-poly (vinyl alcohol) dispersion (MDLC) films with high thermal conductivity containing microscopic-ordered structure were prepared by introducing a highly ordered liquid crystalline monomer (LCM) exhibiting Smectic phase. The thermal conductivity of MDLC films was strongly related to the amount of LCM, which firstly increased and then decreased with the increase of LCM content. The thermal conductivity of MDLC film reached up to 1.20 W m −1 K −1 when the content of LCM was 15 wt% and rapidly decreased to 0.85 W m −1 K −1 as the content of LCM further increased to 25 wt%. LCM with low content (1–15 wt%) showed good fluidity, dispersity and interfacial compatibility in PVA molecular chains, which further increases the regularity of molecular chains alignment.
研究领域:
材料科学
·
热传导研究
✓ 已验证
产品关联
DOI
高影响因子
LIQUID CRYSTALS
·
2013
·
IF 1.959
Jianqiang Xie,Guangming Zhu,Yusheng Tang,Zengping Zhang
Two nematic liquid crystal (LC) monomers containing double bonds in the side chain were designed and synthesised. Length of the side groups varied from 1 to 2 methylene units. The side-chain polymers were synthesised by hydrosilylation reaction. The molecular structures of the intermediates and the LC monomers were characterised by Fourier transform infrared, elemental analysis and nuclear magnetic resonance spectroscopy. The thermal phase behaviour of the monomers and polymers were investigated by differential scanning calorimetry and polar optical microscopy coupled with hot stage. The LC monomers showed only one nematic mesophase in the cooling process. And, the two polymers exhibit an enantiotroppic nematic mesophase either in the heating or in the cooling process.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Li-Li Yao,Jun-Li Wang,Rong-Fa Xu,Ming Zhu,Yan Ma,Bin Tang,Qi-Yuan Lu,Feng-Shan Cai,Xiao Yan,Jing Zheng,Yun-Jiang Yu
Liquid crystal monomers (LCMs) are potentially persistent, bioaccumulating, and toxic substances. However, limited data are available on the occurrence of LCMs in indoor and outdoor air particle matter (PM 10 ) in residential areas. Herein, residential areas near an e-waste dismantling center (Guiyu Town, Shantou City), as well as areas away from the e-waste site (Jiedong District, Jieyang City) were selected as the sampling areas. PM 10 was collected from the indoor environments of Guiyu (IGY) and Jieyang (IJY), as well as those from the outdoor environments (OGY and OJY) using the high-volume air samplers (TH-10000C). The levels of 57 LCMs in PM 10 were analyzed, and the highest concentrations of LCMs were found in IGY (0.970–1080 pg/m 3 ), followed by IJY (2.853–455 pg/m 3 ), OGY (0.544–116 pg/m 3 ) and OJY (0.258–35.8 pg/m 3 ). No significant difference was observed for LCM levels in indoor PM 10 between the two areas ( p > 0.05), which were significantly higher than those in outdoors ( p < 0.05), indicating that the release of electronic products in general indoor environments is a source of LCMs that cannot be ignored. The compositions of LCMs in outdoors were not consistent with those of indoors. The correlation analysis of individual LCMs suggested potential different sources to the LCMs in indoor and outdoor environments. The median daily intake values of Σ 46 LCMs via inhalation were estimated as 0.440, 1.46 × 10 −2 , 0.170 and 1.19 × 10 −2 ng/kg BW/day for adults, and as 2.27, 2.60 × 10 −2 , 0.880 and 2.10 × 10 −2 ng/kg BW/day for toddlers, respectively, indicating much higher exposure doses of LCMs indoors compared with the outdoors, and much higher doses for toddlers compared with adults ( p < 0.05). These results reveal the potentially adverse effects of LCMs on vulnerable populations, such as toddlers, in indoor environments.
研究领域:
环境科学
·
公共卫生
✓ 已验证
DOI
PubMed
高影响因子
ACS Applied Polymer Materials
·
2025
·
IF 4.7
Yanhan Tao,Hui Yang,Zhijun Liu,Guoming Yuan,Kunxin Wang,Kun Wu,Jun Shi
One kind of liquid crystal monomer (LM) based on a biphenyl mesomorphic unit was synthesized from 4,4′-biphenyldicarboxaldehyde and 4-amino-3-methylphenol. Then two films (LM/TPTMP and LM/PETMP) were prepared by reacting the two thiols (TPTMP and PETMP) with the liquid crystal monomer (LM), respectively. These two films simultaneously exhibit intrinsically high thermal conductivity and intrinsic self-healing properties. Due to the presence of biphenyl liquid crystal units in LM and its highly symmetrical structure, a distinct nematic liquid crystal phase can be observed through a polarized optical microscope when heated to the liquid crystal phase transition temperature. The crystallite size of LM was calculated as 37 nm by an X-ray diffractometer (XRD). The films exhibit outstanding thermal conductivity, with LM/TPTMP achieving a thermal conductivity in the horizontal direction (λ∥) of 0.700 W/(m·K), which is significantly higher than that of epoxy resin-based intrinsic thermal conductivity materials in the range of 0.2–0.4 W/(m·K). The introduction of thiol flexible segments endowed the materials with good mechanical strength, with LM/PETMP demonstrating a tensile strength of 4.74 MPa and an elongation at break of 42.57%. Furthermore, the incorporation of dynamic imine bonds imparted excellent self-healing properties to the films. Specifically, LM/PETMP could retain 73% and 65.2% of its original tensile strength after one and three cycles of self-healing behavior, respectively. This type of high intrinsic thermal conductivity (λ) and excellent intrinsic self-healing performance film is expected to solve the problems of safety and service life of high-precision smart devices.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
LIQUID CRYSTALS
·
2020
·
IF 2.908
Duo Wang,Ruo-Yan Li,Yuan-Yuan Quan,Qing-Qing He,Mei Tian,Dan-Shu Yao
Twenty novel azobenzene liquid crystal micromolecular compounds named ω-[4-(p-substituted azobenzeneoxy carbonyl]acid (X-ABCnA) have been designed and synthesised, followed by studies on the thermal performance and mesomorphic properties of the compounds. The liquid crystal compounds were divided into five homologous series based on the terminal substituents R (R = CH3O, CH3, H, Cl, NO2). In each series, the number of carbons on flexible chain was 4, 6, 8 and 10, respectively. Fourier-transform infrared, proton nuclear magnetic resonance and elementary analysis demonstrated that the structure of the synthesised azobenzene liquid crystal compounds was consistent with the molecular design. The mesomorphic properties were tested, analysed and characterised by using differential scanning calorimetry and polarised optical microscopy. The melting transition (Tm) of all the compounds in homologous series with different substituents appeared to decrease with the increase of carbon numbers on flexible chains. The same held true for the temperature of isotropic-mesophase/crystalline transition. The compounds with stronger polarity of terminal substituents were more likely to form broader mesogenic ranges. The liquid crystal compounds discussed in this work can be regarded as a reference for the synthesis of mesogenic arms participating in the synthesis of novel multi-arm liquid crystalline macromolecules and polymers.
研究领域:
材料科学
·
有机化学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2023
·
IF 11.4
Xifen Zhu,Yuanyuan Yu,Weikun Meng,Jiahui Huang,Guanyong Su,Yin Zhong,Xiaolong Yu,Jianteng Sun,Ling Jin,Ping’an Peng,Lizhong Zhu
Fluorinated liquid crystal monomers (FLCMs) have been suggested as emerging contaminants, raising global concern due to their frequent occurrence, potential toxic effects, and endurance capacity in the environment. However, the environmental fate of the FLCMs remains unknown. To fill this knowledge gap, we investigated the aerobic microbial transformation mechanisms of an important FLCM, 4-[difluoro(3,4,5-trifluorophenoxy)methyl]-3, 5-difluoro-4′-propylbiphenyl (DTMDPB), using an enrichment culture termed as BG1. Our findings revealed that 67.5 ± 2.1% of the initially added DTMDPB was transformed in 10 days under optimal conditions. A total of 14 microbial transformation products obtained due to a series of reactions (e.g., reductive defluorination, ether bond cleavage, demethylation, oxidative hydroxylation and aromatic ring opening, sulfonation, glucuronidation, O-methylation, and thiolation) were identified. Consortium BG1 harbored essential genes that could transform DTMDPB, such as dehalogenation-related genes [e.g., glutathione S-transferase gene (GST), 2-haloacid dehalogenase gene (2-HAD), nrdB, nuoC, and nuoD]; hydroxylating-related genes hcaC, ubiH, and COQ7; aromatic ring opening-related genes ligB and catE; and methyltransferase genes ubiE and ubiG. Two DTMDPB-degrading strains were isolated, which are affiliated with the genus Sphingopyxis and Agromyces. This study provides a novel insight into the microbial transformation of FLCMs. The findings of this study have important implications for the development of bioremediation strategies aimed at addressing sites contaminated with FLCMs.
研究领域:
环境科学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Wanlun Li,Shutao Wang,Huize Fan,Ziwei Wang,Yingying Liu,Hong You
Fluorinated liquid crystal monomers (FLCMs) are widely employed in liquid crystal display (LCD) panels. As emerging environmental contaminants with persistent, bioaccumulative, and toxic properties, FLCMs were proven to accumulate in liver, raising great concern regarding potential hepatotoxicity. 1-Ethoxy-2,3-difluoro-4-(trans-4-propylcyclohexyl) benzene (EDPrB), as one representative FLCM, was chosen to investigate the hepatotoxicity in adult zebrafish (Danio rerio) at environmentally relevant concentrations (1, 10, and 100 μg/L) with long-term exposure (21 days). EDPrB caused morphological abnormalities, elevated transaminase activities, and inhibited antioxidant levels in zebrafish liver. The contents of total cholesterol and triglyceride were reduced by 2.3- and 1.82-fold, respectively, at 100 μg/L of EDPrB. Transcriptomic analysis revealed that EDPrB disrupted the lipid and glucose metabolisms, protein processing in endoplasmic reticulum (ER), and P53 signal pathway by dysregulating genes, such as fasn, acaca, acsl1b, hkdc1, xbp1, and ero1lb. EDPrB induced ER stress by activating PERK-eIF2α pathway, leading to hepatic metabolic dysfunction. PERK-eIF2α and P53-Bax/Bcl2 pathways were involved in EDPrB-induced apoptosis. Additionally, molecular simulation confirmed that EDPrB had a strong binding affinity to some lipid metabolism proteins (-8.9~-6.7 kcal/mol) and stress proteins (-9.3~-5.8 kcal/mol). The findings elucidate EDPrB-induced hepatotoxicity and underlying mechanisms, which contribute to assessing the ecological risk and pollution control of FLCMs.
研究领域:
环境科学
·
毒理学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2023
·
IF 11.4
Qianqian Jin,Jianxin Yu,Yinzheng Fan,Yuting Zhan,Danyang Tao,Jingchun Tang,Yuhe He
Liquid crystal display (LCD) screens can release many organic pollutants into the indoor environment, including liquid crystal monomers (LCMs), which have been proposed as a novel class of emerging pollutants. Knowing the release pathways and mechanisms of LCMs from various components of LCD screens is important to accurately assess the LCM release and reveal their environmental transport behavior and fate in the ambient environment. A total of 47, 43, and 33 out of 64 target LCMs were detected in three disassembled parts of waste smartphone screens, including the LCM layer (LL), light guide plate (LGP), and screen protector (SP), respectively. Correlation analysis confirmed LL was the source of LCMs detected in LGP and SP. The emission factors of LCMs from waste screen, SP, and LGP parts were estimated as 2.38 × 10–3, 1.36 × 10–3, and 1.02 × 10–3, respectively. A mechanism model was developed to describe the release behaviors of LCMs from waste screens, where three characteristics parameters of released LCMs, including average mass proportion (AP), predicted subcooled vapor pressures (PL), and octanol–air partitioning coefficients (Koa), involving coexistence of absorption and adsorption mechanisms, could control the diffusion-partitioning. The released LCMs in LGP could reach diffusion-partition equilibrium more quickly than those in SP, indicating that LCM release could be mainly governed through SP diffusions.
研究领域:
环境科学
·
污染控制
·
有机化学
✓ 已验证
DOI
PubMed
高影响因子
Environmental Science-Nano
·
2024
·
IF 5.8
Yiping Feng,Jingyi Wu,Wenhao Lao,Weibiao Ye,Danni Guo,Zhu Wang,Xiaowei Wu,Racliffe Weng Seng Lai
Micro- and nanoplastics are emerging pollutants that have attracted significant attention due to their potential to concentrate and transport coexisting organic pollutants in aquatic environments. Fluorinated liquid-crystal monomers (FLCMs) have also emerged as contaminants of concern, given their frequent occurrence, potential toxic effects, and propensity to co-occur with plastics in the environment. However, the influence of plastics on the environmental fate of FLCMs remains unclear yet. To address this knowledge gap, we investigated the accumulation of a key FLCM, 4-cyano-3-fluorophenyl 4-ethylbenzoate (CEB-F), on three common plastics, and examined the effects of nanoplastics on the phototransformation of CEB-F and its acute toxicity to Daphnia magna (D. magna). Our findings revealed that the adsorption capacity of CEB-F on different plastic materials followed the order: polystyrene (PS) < mixed cellulose ester (MCE) < polyamide (PA). The adsorption processes of CEB-F on the three plastics aligned more closely with the pseudo-first-order kinetic model and the Langmuir isotherm model, suggesting that the adsorption is primarily governed by physical diffusion. Theoretical calculations indicated that the adsorption of CEB-F on PS plastics is mainly driven by hydrophobic interactions. Additionally, PS nanoplastics (PSNPs) significantly enhanced the UV degradation of CEB-F, although the types of degradation intermediates did not change substantially, suggesting a limited impact on the degradation process and mechanism. Acute toxicity tests showed that PSNPs increased the toxicity of CEB-F to D. magna at lower concentrations, while the toxicity was reduced at higher concentrations. The obtained findings are of great significance to unraveling the plastic-mediated environmental fate and aquatic toxicity of FLCMs in natural waters.
研究领域:
环境科学
·
毒理学
·
生态学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2024
·
IF 5.7
YueYue Zhang,Dingliang Tang,Yuanfei Wu,Xiaojia Huang
Background Liquid crystal monomers (LCMs) have been classified as emerging organic pollutants . Efficient isolation and extraction is a critical step in the determination, and then knowing the occurrence and distribution of LCMs in environmental waters. However, the reported sample preparation techniques still suffer some dilemmas such as using large amount of organic solvent , low extraction capacity, tedious operation procedure and employment of expensive extraction column. To circumvent the disadvantages, new extraction format and adsorbent with quickness, less consumption of organic solvent, superior extraction performance and low cost should be developed for the analysis of LCMs. Results Using 1H,1H,2H,2H-heptadecafluorodecyl acrylate and 9-vinylanthracene as mixed functional monomers , a task specific magnetic adsorbent (TSMA) was prepared by one-pot hydrothermal technique for the highly efficient capture of LCMs under magnetic solid phase extraction (MSPE) format. Due to the abundant functional groups, the developed TSMA/MSPE presented satisfactory capture performance towards LCMs. Satisfactory enrichment factors (132–212) and high adsorption capacity (18 mg/g) were obtained. Additionally, the relevant adsorption mechanism was studied by the combination of density functional theory calculation and experiments about adsorption kinetics and adsorption isotherm . Under the beneficial conditions, a sensitive and reliable method for the monitoring of studied LCMs in environmental waters was established by the combination of TSMA/MSPE with HPLC equipped with diode array detector (DAD). The achieved limits of detection and spiked recoveries were 0.0025–0.0061 μg/L and 81.0–112 %, respectively. Finally, the developed method was employed to monitor LCMs levels in the North Creek watershed of Jiulong River. Significance and novelty The current study provided a new adsorbent for quick and efficient capture of LCMs at trace levels. In addition, a sensitive, reliable and anti-intereference method for the monitoring of trace LCMs in actual waters was established. Moreover, for the first, the contents, occurrence and distribution of LCMs in North Creek watershed was investigated based on the developed method.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Crystals
·
2023
·Vol. 13
·期 9
·1294
·
IF 2.7
Cong Ma,Yishuo Wu,Meina Yu,Yanzi Gao,Jiumei Xiao,Cheng Zou,Huai Yang
Polymer-dispersed liquid-crystal (PDLC) films have wide applications in light shutters, smart windows for cars and buildings, dimming glasses, and smart peep-proof films due to their switchable optical states under electrical fields as well as large area processibility. They are usually prepared with liquid crystals (LCs) and non-liquid crystalline monomers (NLCMs). Introduction of liquid crystalline monomers (LCMs) into PDLCs might spark new functionality or high-performance devices such as polymer-dispersed and -stabilized liquid crystals. In this study, the effect of molecular structures and doping concentrations of acrylate LCMs on the electro-optical properties and micro-structures of PDLC films is systematically studied. The pore size of polymer networks and the driving voltage of the PDLC films are affected by the molecular polarity and degree of functionality of the LCMs. The electro-optical properties of the PDLC films are affected by the synergistic influence of molecular structure of LCMs and micro-structures of PDLCs. These results might provide the experimental and theoretical basis for constructing the relationship between the molecular structure of LCM, micro-structure and electro-optical response of PDLC films.Keywords:liquid crystalline monomers;acrylates;polymer-dispersed liquid crystals;electro-optical properties;micro-structure
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）