Polyvinylchloride

聚氯乙烯
  • 文章类型: Journal Article
    微生物在塑料聚合物上的定植已经得到了广泛的探索,然而,南极环境中生物膜群落的时间动态几乎是未知的。作为填补这一知识空白的贡献,在罗斯海的四个沿海地点调查了与聚氯乙烯(PVC)和聚乙烯(PE)板淹没在5m深度并在3、9和12个月后收集的生物膜的结构特征和微生物多样性。12个月后取回放置在5和20m处的其他面板。通过FTIR-ATR和拉曼(通过表面增强拉曼散射,SERS)光谱学。通过催化报告物沉积荧光原位杂交(CARD-FISH)和共聚焦激光扫描显微镜(CLSM)在单细胞水平定量细菌群落组成;通过16SrRNA基因测序评估微生物多样性。这种多学科方法为生物污染过程中的微生物群落动态提供了新的见解,在罗斯海的塑料基质上释放生物膜多样性和时间演替的光。发现自由生活和微生物生物膜群落之间存在显着差异,与PE相比,PVC的社区组成更加巩固和结构化。酪氨酸的光谱特征,多糖,核酸和脂质表征了PVC相关的生物膜。假单胞菌(在γ变形杆菌中)和α变形杆菌在微生物生物膜群落中占主导地位。有趣的是,在路湾,靠近意大利“马里奥·祖切利”研究站,生物膜生长-已经在夏季观察到,经过3个月的浸没-之后继续导致大量的微生物丰度在冬季结束(12个月后)。三个月后,在RoadBay发现的Gammaproteobacteria百分比高于未受影响的站点。这些观察结果使我们假设,在该地点,前3个月中产生的微生物污垢可以作为启动先驱社区,刺激冬季的连续生长。
    Microbial colonization on plastic polymers has been extensively explored, however the temporal dynamics of biofilm community in Antarctic environments are almost unknown. As a contribute to fill this knowledge gap, the structural characteristics and microbial diversity of the biofilm associated with polyvinyl chloride (PVC) and polyethylene (PE) panels submerged at 5 m of depth and collected after 3, 9 and 12 months were investigated in four coastal sites of the Ross Sea. Additional panels placed at 5 and 20 m were retrieved after 12 months. Chemical characterization was performed by FTIR-ATR and Raman (through Surface-Enhanced Raman Scattering, SERS) spectroscopy. Bacterial community composition was quantified at a single cell level by Catalyzed Reporter Deposition Fluorescence In Situ Hybridization (CARD-FISH) and Confocal Laser Scanning Microscopy (CLSM); microbial diversity was assessed by 16S rRNA gene sequencing. This multidisciplinary approach has provided new insights into microbial community dynamics during biofouling process, shedding light on the biofilm diversity and temporal succession on plastic substrates in the Ross Sea. Significant differences between free-living and microbial biofilm communities were found, with a more consolidated and structured community composition on PVC compared to PE. Spectral features ascribable to tyrosine, polysaccharides, nucleic acids and lipids characterized the PVC-associated biofilms. Pseudomonadota (among Gamma-proteobacteria) and Alpha-proteobacteria dominated the microbial biofilm community. Interestingly, in Road Bay, close to the Italian \"Mario Zucchelli\" research station, the biofilm growth - already observed during summer season, after 3 months of submersion - continued afterwards leading to a massive microbial abundance at the end of winter (after 12 months). After 3 months, higher percentages of Gamma-proteobacteria in Road Bay than in the not-impacted site were found. These observations lead us to hypothesize that in this site microbial fouling developed during the first 3 months could serve as a starter pioneering community stimulating the successive growth during winter.
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  • 文章类型: Journal Article
    属于Monomoriumindicum(Formicidae:膜翅目)物种的蚂蚁是普遍存在的昆虫,通常与巴基斯坦的家庭环境有关。当用具有高敏感性的材料进行包装时,包装的食品容易被家庭蚂蚁破坏。这项研究评估了三种常见的柔性塑料包装材料的敏感性:不透明聚乙烯,透明聚乙烯和聚丙烯,分别在0.02mm的厚度下测试它们对M.indicum的敏感性。除了不透明的聚乙烯,它只能在0.02毫米的厚度,透明聚乙烯和聚丙烯都在0.04mm和0.06mm的较高厚度下进行了测试。为了模拟家庭设置,实验是在巴哈瓦尔布尔伊斯兰大学农业和环境部的教学楼进行的,巴基斯坦在暑假期间,大楼很安静。在水源附近选择不同的角落,以最大程度地暴露于最大数量的蚂蚁。用于实验的实验笼用木材和2mm铁纱布建造,以仅允许蚂蚁进入笼中。蚂蚁的日常活动被用作笼子中的侵扰源。实验在2022年6月20日至2022年8月15日的三个时间间隔内进行,每个时间间隔为15天。结果表明,所有包装材料在0.02mm厚度水平下均对野牛分枝杆菌敏感。聚丙烯在厚度为0.04mm时易受影响,但在厚度为0.06mm时耐蚂蚁,而聚乙烯在0.06毫米的较高厚度下仍然容易受到蚂蚁的影响。包装破损与天气因素的相关性表明,温度呈正相关,而相对湿度与M.indicum发作呈负相关。包装损坏与包装厚度的总体相关性表明,包装厚度与蚂蚁的包装损坏呈负相关。因为主要的切割作用是由下颌骨完成的,我们研究了蚂蚁的下颌骨和包装食品的三种常见害虫,即rhyzoperthadominica,蓖麻和谷基。结果表明,与常见的储存产品害虫的下颌骨和前牙相比,蚂蚁的下颌骨和前牙长度最大,这表明,与常见的储存产品害虫相比,in草家用蚂蚁对包装食品的害虫状况更高。尽管柔性塑料包装的厚度是对抗家用蚂蚁的主要因素,研究结果表明,与聚乙烯包装相比,使用厚度至少为0.06毫米的聚丙烯作为食品包装来对抗家用蚂蚁,即使在0.06毫米的厚度下也容易受到蚂蚁的影响。
    Ants belonging to the Monomorium indicum (Formicidae: Hymenoptera) species are ubiquitous insects that are commonly associated with household settings in Pakistan. Packaged foodstuffs are easily destroyed by household ants when packaging is made with materials that have a high susceptibility. This study evaluated the susceptibility of three common flexible plastic packaging materials namely: opaque polyethylene, transparent polyethylene and polypropylene, which were each tested at thicknesses of 0.02 mm for their susceptibility against M. indicum. Except opaque polyethylene which is only available at 0.02 mm thickness, both transparent polyethylene and polypropylene were tested at higher thickness of 0.04 mm and 0.06 mm also against M. indicum. In order to simulate household settings, experiments were conducted at the faculty building of the agriculture and environment department of The Islamia University of Bahawalpur, Pakistan during summer vacations when the building was quiet. Different corners were selected near water sources for maximum exposure to the largest number of ants. Experimental cages used for the experiment were built with wood and 2 mm iron gauze to allow only ants to enter the cages. Daily activity of ants was used as an infestation source in cages. Experiments were run over three time spans of fifteen days each from June 20th 2022 to August 15th 2022. Results showed all packaging materials were susceptible against M. indicum at the 0.02 mm thickness level. Polypropylene was susceptible at 0.04 mm thickness but resistant to ants at 0.06 mm thickness, whereas polyethylene was still susceptible to ants at the higher thickness of 0.06 mm. Correlation of packaging damage with weather factors showed that temperature had a positive relationship, while relative humidity had a negative association with M. indicum attack. Overall correlation of packaging damage with packaging thickness showed packaging thickness was negatively associated with packaging damage from the ants. Because major cutting role is performed by the mandibles, we studied mandibles of ants and three frequent pests of packaged foodstuff namely Rhyzopertha dominica, Tribolium castaneum and Trogoderma granarium. The results showed that ants had the largest mandible and frontal mandibular tooth lengths compared with the mandibles and frontal teeth of the common stored product pests, indicating M. indicum household ants have a higher pest status for packaged foodstuffs compared to common stored product pests. Although the thickness of the flexible plastic packaging was a major factor against household ants, the study results recommend the use of polypropylene with a thickness of at least 0.06 mm as foodstuff packaging against household ants compared with polyethylene packaging, which was found to be susceptible to ants even at 0.06 mm thickness.
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  • 文章类型: Journal Article
    化学工业是主要的化石燃料消费国之一,因此,应增加对风能和太阳能等可持续和可再生资源的依赖,以保护环境。因此,这项工作提出了在自然阳光下使用聚氯乙烯(PVC)负载的氧化铝(Al2O3)作为催化剂的太阳能驱动的热催化合成八氢喹唑啉酮。采用FT-IR对Al2O3/PVC催化剂进行了表征,SEM,BET,XRD,和XPS技术。结果表明,可以通过调节催化剂的摩尔比来改善产率和反应时间。为了研究催化剂的稳定性,用过的催化剂在几个反应中重复使用。结果表明,当在绝对太阳热中使用50%的Al2O3催化剂时,它在产率(98%)和反应时间(35分钟)方面表现非常好。此外,具有芳基部分的八氢喹唑啉酮衍生物的反应时间和收率优于杂芳基。所有合成的化合物都通过FT-IR得到了良好的表征,1H-NMR,和13C-NMR。目前的工作介绍了一种新的战略,利用太阳能热进行节能的化学反应,可回收环保型PVC/Al2O3催化剂,产量高。
    The chemical industry is one of the main fossil fuel consumers, so its reliance on sustainable and renewable resources such as wind and solar energy should be increased to protect the environment. Accordingly, solar-driven thermocatalytic synthesis of octahydroquinazolinone using polyvinylchloride (PVC)-supported aluminum oxide (Al2O3) as a catalyst under natural sunlight is proposed in this work. The Al2O3/PVC catalysts were characterized by FT-IR, SEM, BET, XRD, and XPS techniques. The obtained results indicate that the yield and reaction time can be modified by adjusting the molar ratio of the catalyst. To investigate the stability of the catalyst, the spent catalyst was reused in several reactions. The results indicated that, when a 50% Al2O3 catalyst is employed in an absolute solar heat, it performs exceptionally well in terms of yield (98%) and reaction time (35 min). Furthermore, the reaction times and yield of octahydroquinazolinone derivatives with an aryl moiety were superior to those of heteroaryl. All the synthesized compounds were well characterized by FT-IR, 1H-NMR, and 13C-NMR. The current work introduces a new strategy to use solar heat for energy-efficient chemical reactions using a cost-effective, recyclable environmentally friendly PVC/Al2O3 catalyst that produces a high yield.
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  • 文章类型: Journal Article
    微塑料污染在全球范围内引起了越来越多的关注。微塑料可能会浓缩有机和金属污染物;因此,影响他们的运输,命运和有机暴露。为了更好地了解有机污染物-微塑料的相互作用,我们的研究探索了选定的多氯联苯(PCBs)的吸附,多溴联苯醚(PBDEs),α-六溴环十二烷(α-HBCDD),和有机磷酸酯阻燃剂(OPFRs)在盐水条件下的高密度聚乙烯(HDPE)和聚氯乙烯(PVC)微塑料。确定的吸附等温线在化学品之间以及在HDPE和PVC微塑料之间变化。对于HDPE,目标化学品的LogFreundlich吸附系数(LogKF)范围为2.01至5.27Lkg-1,但PVC的含量明显较低,即,范围从LogKF数据(2.84-8.58Lkg-1)。化学品\'LogKF和LogKow(辛醇-水分配系数)之间的显着相关性表明,化学依赖性吸附在很大程度上受其疏水性影响。使用三种尺寸类别(<53、53-300和300-1000μm)的实验室破碎的微塑料评估吸附。粒径没有显著影响吸附等温线,但影响了达到平衡的时间和预测的最大吸附,可能与微塑料表面积有关。HDPE颗粒上生物膜的存在显着增强了污染物的吸附能力,表明化学-生物膜-微塑料系统中更复杂的吸附动力学。我们的发现为海洋环境中的化学-微塑料相互作用提供了新的见解。
    Microplastic pollution has attracted mounting concerns worldwide. Microplastics may concentrate organic and metallic contaminants; thus, affecting their transport, fate and organismal exposure. To better understand organic contaminant-microplastic interactions, our study explored the sorption of selected polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), α-hexabromocyclododecane (α-HBCDD), and organophosphate flame retardants (OPFRs) on high-density polyethylene (HDPE) and polyvinylchloride (PVC) microplastics under saline conditions. Sorption isotherms determined varied between chemicals and between HDPE and PVC microplastics. Log Freundlich sorption coefficients (Log KF) for the targeted chemicals ranged from 2.01 to 5.27 L kg-1 for HDPE, but were significantly lower for PVC, i.e., ranging from Log KF data (2.84 - 8.58 L kg-1). Significant correlations between chemicals\' Log KF and Log Kow (octanol-water partition coefficient) indicate that chemical-dependent sorption was largely influenced by their hydrophobicity. Sorption was evaluated using three size classes (< 53, 53 - 300, and 300 - 1000 µm) of lab-fragmented microplastics. Particle size did not significantly affect sorption isotherms, but influenced the time to reach equilibrium and the predicted maximum sorption, likely related to microplastic surface areas. The presence of biofilms on HDPE particles significantly enhanced contaminant sorption capacity, indicating more complex sorption dynamics in the chemical-biofilm-microplastic system. Our findings offer new insights into the chemical-microplastic interactions in marine environment.
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  • 文章类型: Journal Article
    邻苯二甲酸盐和其他增塑剂广泛用于医疗设备(MD),它们可以从中浸出并导致患者潜在的多种问题。这种暴露是一个主要问题,因为它与生殖和神经发育障碍有关。新生儿重症监护病房(NICU)人群由于每天的强化医疗干预而处于高风险,新生儿去除这些污染物的能力降低,对内分泌干扰物的敏感性更高。我们进行了一项多中心生物监测研究,以评估和比较DEHP(邻苯二甲酸二(2-乙基己基)酯)的尿水平,DEHTP(对苯二甲酸二-(2-乙基己基)酯)和TEHTM(三-(2-乙基己基)偏苯三酸酯)代谢物作为新生儿在NICU期间和之后暴露的生物标志物。在NICU和出院时收集每位患者的每日尿样品。还调查了MD来源和暴露因素。收集了来自中心1和2(C1/C2)的97名患者的508例尿液样本。新生儿对DEHP的暴露量大于DEHTP和TEHTM,DEHP代谢物的中位浓度(C1:195.63ng/mL;C2:450.87ng/mL)分别比DEHTP和TEHTM代谢物的中位浓度高5至10倍和57至228倍。出院时DEHP和TEHTM代谢物的尿浓度显著低于NICU,DEHP下降了18倍和35倍,TEHTM下降了4倍和8倍,分别对于C1和C2,但对于DEHTP代谢物相似。用于呼吸辅助的MD,输液治疗,肠内营养和输血是主要的暴露来源。较小的胎龄和体重显着增加了新生儿的暴露量。NICU患者中DEHP代谢物水平的升高仍然令人担忧。需要额外的努力来促进其在MD的替代可能更安全的替代品,如TEHTM和DEHTP,特别是当用于照顾新生儿。
    Phthalates and other plasticisers are extensively used in medical devices (MD) from which they can leach out and lead to potential multiple problems for the patients. This exposure is a major issue because it is associated with reproductive and neurodevelopment disorders. The Neonatal Intensive Care Units (NICU) population is at high risk due to the daily intensive medical interventions, the reduced ability of newborns to remove these contaminants and their higher sensitivity to endocrine disruptors. We conducted a multicentric biomonitoring study to assess and compare the urinary levels of DEHP (di-(2-ethylhexyl)phthalate), DEHTP (di-(2-ethylhexyl)terephthalate) and TEHTM (tri-(2-ethylhexyl)trimellitate) metabolites as biomarkers of this exposure during and after the newborns\' stay in NICU. Daily urinary samples were collected in NICU and at discharge from the hospital for each patient. MD sources and exposure factors were also investigated. 508 urinary samples from 97 patients enrolled in centres 1 and 2 (C1/C2) were collected. The exposure of newborns to DEHP was greater than that of DEHTP and TEHTM, with a median concentration of DEHP metabolites (C1:195.63 ng/mL;C2:450.87 ng/mL) respectively 5 to 10 times higher and 57 to 228 times higher than the median concentrations of DEHTP and TEHTM metabolites. The urinary concentrations of DEHP and TEHTM metabolites were significantly lower at discharge than in NICU, with a 18-and 35-fold decrease for DEHP and a 4 and 8-fold decrease for TEHTM, respectively for C1 and C2, but were similar for DEHTP metabolites. MD used for respiratory assistance, infusion therapy,enteral nutrition and transfusion were the main sources of exposure. Smaller gestational age and body weight significantly increased the newborns\' exposure. The elevated levels of DEHP metabolites in NICU patients are still alarming. Additional efforts are necessary to promote its substitution in MD by possibly safer alternatives such as TEHTM and DEHTP, particularly when used for the care of newborns.
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  • 文章类型: Journal Article
    从聚苯乙烯(PS)等聚合物开发聚合物膜,聚氯乙烯(PVC),以及他们的相关家庭为环境修复世界带来了巨大的动力,主要是由于其惊人的多样性和多用途的性质。在过去的半个世纪中,它们的使用量激增了20倍,并且在未来20年中可能会再次增加一倍。因此,聚合材料经济和研究的商业化变得越来越重要,作为一个国家促进繁荣的可能选择,同时减少对有限原始资源的依赖,减轻负外部性。这种转变需要一个系统的战略,这涉及到改进现有模型和建立新的合作途径之外的进展。在这项工作中,一个复杂的系统,即,产品空间模型(PSM),已经提出,明确评估英国的机会空间,意大利,波兰,印度,加拿大,印度尼西亚,巴西,沙特阿拉伯,俄罗斯和哥伦比亚对用于环境修复的聚合物膜的潜在未来工业化和商业化。结果显示,英国,意大利,波兰和印度处于有利地位,因为它们距离(距离<2)很近,而且在节俭政策中处于有利地位,这是PSM策略地图中最想要的象限,加拿大和印度尼西亚有中等水平的机会,虽然俄罗斯和沙特阿拉伯有机会和更多的挑战,以充分利用未开发的聚合物产品在环境修复膜方面,并证明有利于出口多样化,可持续经济增长,和商业化。
    The development of polymeric membranes from polymers such as polystyrene (PS), polyvinylchloride (PVC), and their associated family has brought great momentum to the environmental remediation universe, mainly due to their surprisingly diverse and multi-purpose nature. Their usage has surged 20 times in the last half-century and is likely to double again in the coming 20 years. As a result, the polymeric materials economy and commercialization of research become increasingly important as a possible option for a country to boost prosperity while decreasing its reliance on limited raw resources and mitigating negative externalities. This transformation demands a systematic strategy, which involves progress beyond improving the existing models and building new avenues for collaboration. In this work, a sophisticated system, i.e., product space model (PSM), has been presented, explicitly appraising the opportunity space for United Kingdom, Italy, Poland, India, Canada, Indonesia, Brazil, Saudi Arabia, Russia and Colombia for their potential future industrialization and commercialization of polymeric membranes for environmental remediation. The results revealed that UK, Italy, Poland and India are at advantageous positions owing to their close proximity of (distance<2) and their placement in Parsimonious policy, which is the most desired quadrant of Policy Map of PSM, Canada and Indonesia have medium level opportunities, while Russia and Saudi Arabia have opportunities with more challenges to fully exploit the unexploited polymers products in terms of membranes for environmental remediation and prove favorable for export diversification, sustainable economic growth, and commercialization.
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  • 文章类型: Journal Article
    制备了一种新的溴化十六烷基吡啶/聚氯乙烯(CPB/PVC)吸附剂,并进行了测试,以从其氯化物溶液中提取稀土元素(REE)。通过FTIR鉴定,TGA,SEM,EDX,和XRD。pH等各种因素的影响,RE离子初始浓度,接触时间,并通过吸附过程检查剂量。最佳pH为6.0,在25°C下达到60分钟的平衡接触时间。制备的吸附剂(CPB/PVC)吸收能力为182.6mg/g。发现RE离子在CPB/PVC吸附剂上的吸附很好地符合Langmuir等温线和伪二阶模型。此外,发现RE离子吸附的热力学参数是放热的和自发的。研究了RE离子从负载的CPB/PVC吸附剂中的解吸。观察到,在环境室温和1:60的固液相比(S:L)下,在1.0MHCl下接触60分钟,实现了最佳的解吸。因此,制备的CPB/PVC吸附剂被认为是REE的竞争吸附剂。
    A new sorbent cetylpyridinium bromide/polyvinylchloride (CPB/PVC) was prepared and tested to extract rare earth elements (REEs) from their chloride solutions. It was identified by FTIR, TGA, SEM, EDX, and XRD. The impact of various factors such as pH, RE ion initial concentration, contacting time, and dose amount via sorption process was inspected. The optimum pH was 6.0, and the equilibrium contact time was reached at 60 min at 25 °C. The prepared adsorbent (CPB/PVC) uptake capacity was 182.6 mg/g. The adsorption of RE ions onto the CPB/PVC sorbent was found to fit the Langmuir isotherm as well as pseudo-second-order models well. In addition, the thermodynamic parameters of RE ion sorption were found to be exothermic and spontaneous. The desorption of RE ions from the loaded CPB/PVC sorbent was investigated. It was observed that the optimum desorption was achieved at 1.0 M HCl for 60 min contact time at ambient room temperature and a 1:60 solid: liquid phase ratio (S:L). As a result, the prepared CPB/PVC sorbent was recognized as a competitor sorbent for REEs.
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  • 文章类型: Journal Article
    Polyvinylchloride is universally agreed upon to be the material of choice for tubings and for containers for medical application. Many alterations of the chemical/physical surface conditions, mainly due to an altered extrusion process, could influence its biocompatibility by promoting platelet aggregation. Biocompatibility and safety of the medical device must be preserved, also monitoring the migration of additives within polyvinylchloride during the diffusion process. A large variety of methods are used to verify the correct composition and extrusion of polyvinylchloride but, generally, they need long experimental time and are expensive. The aim of the study is to propose a simple, economic and rapid approach based on Fourier transform-infrared spectroscopy and Coomassie Blue staining. The method has been used to detect chemical and morphological defects caused by an altered extrusion process on 20/75 polyvinylchloride tubings in a blind test. This approach positively identified altered samples in 80% of the cases. The suggested approach represents a reliable and versatile method to detect and monitor surface defects by an easy, inexpensive and reproducible method.
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  • 文章类型: Journal Article
    Polymer nanocomposites used in underground cables have been of great interest to researchers over the past 10 years. Their preparation and the dispersion of the nanoparticles through the polymer host matrix are the key factors leading to their enhanced dielectric properties. Their important dielectric properties are breakdown strength, permittivity, conductivity, dielectric loss, space charge accumulation, tracking, and erosion, and partial discharge. An overview of recent advances in polymer nanocomposites based on LDPE, HDPE, XLPE, and PVC is presented, focusing on their preparation and electrical properties.
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  • 文章类型: Journal Article
    Herein, we report the prevalence of microplastics in the South Andaman beaches, India. The average microplastic abundance of the eight stations covered along the South Andaman beach was found to be 414.35 ± 87.4 particles per kilogram of beach sediment. Among the stations sampled, Kodiyaghat was found with highest microplastic abundance of 973.3 ± 76.59 particles per kilogram of beach sediment and Burmanullah recorded the lowest number of 161.7 ± 32.51. Microplastic particles of different types, size, color and shape were present in all the eight stations sampled. From the Raman spectral analysis, thirteen different types of polymers were identified. The microplastic pollution may be attributed to improper solid waste management, tourism activities and maritime activities. The present study will help in understanding the prevalence, source and pathway of microplastic particles and their affiliated risk to the fragile marine ecosystem.
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