基于密度泛函理论研究聚醚类破乳剂的构效关系

油田采出液处理工艺中化学破乳剂的使用能够大大提升工作效率并且节约成本,其中聚醚类破乳剂的应用最为广泛,研究聚醚类破乳剂的构效关系对于新型破乳剂的研发及应用至关重要。本文首先对几种聚醚类破乳剂和反相破乳剂的破乳效果进行了评价和比较,然后根据沥青质分子的结构特点及现有聚醚类破乳剂和反相破乳剂的类型,选取了相应的模型分子,通过密度泛函理论(DFT)中B3LYP/6-31G基组得到其最优分子几何构型和静电势分布图,并利用泛函M062X/6-31G基组计算了聚醚类破乳剂模型分子分别与沥青质模型分子和水分子之间的相互作用能。结合聚醚类破乳剂和反相破乳剂的破乳性能评价结果,进而分析了聚醚类破乳剂的构效关系。结果表明,由理论化学计算结果所推测的破乳剂的破乳性能差异与其实际破乳效果相一致:具有支状结构、聚合度较高的聚醚类破乳剂的效果优于线型结构、聚合度较低的聚醚类破乳剂;酚醛树脂聚醚的破乳效果优于酚胺树脂聚醚,而反相破乳剂中则是多元醇聚醚类反相破乳剂的效果较优。该工作的开展表明采用密度泛函理论进行破乳剂的构效关系研究是可行的,能够为未来新型破乳剂的制备及选用奠定重要的理论基础和提供参考依据。

Ignition processes and characteristics of charring conductive polymers with a cavity geometry in precombustion chamber for applications in micro/nano satellite hybrid rocket motors

The arc ignition system based on charring polymers has advantages of simple structure,low ignition power consumption and multiple ignitions,which bringing it broadly application prospect in hybrid propulsion system of micro/nano satellite.However,charring polymers alone need a relatively high input voltage to achieve pyrolysis and ignition,which increases the burden and cost of the power system of micro/nano satellite in practical application.Adding conductive substance into charring polymers can effectively decrease the conducting voltage which can realize low voltage and low power consumption repeated ignition of arc ignition system.In this paper,a charring conductive polymer ignition grain with a cavity geometry in precombustion chamber,which is composed of PLA and multiwall carbon nanotubes(MWCNT)was proposed.The detailed ignition processes were analyzed and two different ignition mechanisms in the cavity of charring conductive polymers were revealed.The ignition characteristics of charring conductive polymers were also investigated at different input voltages,ignition grain structures,ignition locations and injection schemes in a visual ignition combustor.The results demonstrated that the ignition delay and external energy required for ignition were inversely correlated with the voltages applied to ignition grain.Moreover,the incremental depth of cavity shortened the ignition delay and external energy required for ignition while accelerated the propagation of flame.As the depth of cavity increased from 2 to 6 mm(at 50 V),the time of flame propagating out of ignition grain changed from 235.6 to 108 ms,and values of mean ignition delay time and mean external energy required for ignition decreased from 462.8 to 320 ms and 16.2 to 10.75 J,respectively.The rear side of the cavity was the ideal ignition position which had a shorter ignition delay and a faster flame propagation speed in comparison to other ignition positions.Compared to direct injection scheme,swirling injection provided a more favorable flow field environment in the cavity,which was beneficial to ignition and initial flame propagation,but the ignition position needed to be away from the outlet of swirling injector.At last,the repeated ignition characteristic of charring conductive polymers was also investigated.The ignition delay time and external energy required for ignition decreased with repeated ignition times but the variation was decreasing gradually.

Force Compensation Control for Electro-Hydraulic Servo System with Pump-Valve Compound Drive via QFT-DTOC

Each joint of a hydraulic-driven legged robot adopts a highly integrated hydraulic drive unit(HDU),which features a high power-weight ratio.However,most HDUs are throttling-valve-controlled cylinder systems,which exhibit high energy losses.By contrast,pump control systems offer a high efficiency.Nevertheless,their response ability is unsatisfactory.To fully utilize the advantages of pump and valve control systems,in this study,a new type of pump-valve compound drive system(PCDS)is designed,which can not only effectively reduce the energy loss,but can also ensure the response speed and response accuracy of the HDUs in robot joints to satisfy the performance requirements of robots.Herein,considering the force control requirements of energy conservation,high precision,and fast response of the robot joint HDU,a nonlinear mathematical model of the PCDS force control system is first introduced.In addition,pressure-flow nonlinearity,friction nonlinearity,load complexity and variability,and other factors affecting the system are considered,and a novel force control method based on quantitative feedback theory(QFT)and a disturbance torque observer(DTO)is designed,which is denoted as QFT-DTOC herein.This method improves the control accuracy and robustness of the force control system,reduces the effect of the disturbance torque on the control performance of the servo motor,and improves the overall force control performance of the system.Finally,experimental verification is performed using the PCDS performance test platform.The experimental results and quantitative data show that the QFT-DTOC proposed herein can significantly improve the force control performance of the PCDS.The relevant force control method can be used as a bottom-control method for the hydraulic servo system to provide a foundation for implementing the top-level trajectory planning of the robot.

Assessment and control of the mine tremor disaster induced by the energy accumulation and dispersion of thick-hard roofs

In order to solve the problem that current theory models cannot accurately describe thick-hard roof(THR)elastic energy and assess the mine tremor disasters,a theoretical method,a Timoshenko beam theory on Winkler foundation was adopted to establish the THR’s periodic breaking model.The superposition principle was used for this complex model to derive the calculation formulas of the elastic energy and impact load on hydraulic supports.Then,the influence of roof thickness h,cantilever length L_(1),and load q on THR’s elastic energy and impact load was analyzed.And,the effect of mine tremor disasters was assessed.Finally,it is revealed that:(1)The THR’s elastic energy U exhibits power-law variations,with the fitted relationships U=0.0096L_(1)^(3.5866^),U=5943.9h^(-1.935),and U=21.049q^(2).(2)The impact load on hydraulic supports F_(ZJ) increases linearly with an increase in the cantilever length,thickness,and applied load.The fitted relationships are F_(ZJ)=1067.3L_(1)+6361.1,F_(ZJ)=125.89h+15100,and F_(ZJ)=10420q+3912.6.(3)Ground hydraulic fracturing and liquid explosive deep-hole blasting techniques effectively reduce the THR’s cantilever length at periodic breakages,thus eliminating mine tremor disasters.

Advances of embedded resistive random access memory in industrial manufacturing and its potential applications

Embedded memory,which heavily relies on the manufacturing process,has been widely adopted in various industrial applications.As the field of embedded memory continues to evolve,innovative strategies are emerging to enhance performance.Among them,resistive random access memory(RRAM)has gained significant attention due to its numerousadvantages over traditional memory devices,including high speed(<1 ns),high density(4 F^(2)·n^(-1)),high scalability(~nm),and low power consumption(~pJ).This review focuses on the recent progress of embedded RRAM in industrial manufacturing and its potentialapplications.It provides a brief introduction to the concepts and advantages of RRAM,discusses the key factors that impact its industrial manufacturing,and presents the commercial progress driven by cutting-edge nanotechnology,which has been pursued by manysemiconductor giants.Additionally,it highlights the adoption of embedded RRAM in emerging applications within the realm of the Internet of Things and future intelligent computing,with a particular emphasis on its role in neuromorphic computing.Finally,the review discusses thecurrent challenges and provides insights into the prospects of embedded RRAM in the era of big data and artificial intelligence.

Effect of vinegar supplementation on patients with esophageal lesions lightly stained with Lugol’s iodine solution:Prospective single-centre trial

BACKGROUND Esophageal chromoendoscopy with iodine solution is important for detecting early esophageal cancer.The effect of routine treatment for lesions lightly stained with Lugol’s iodine solution is limited,and the addition of natural substances to a regular diet is becoming increasingly common.Vinegar has antitumor effects as reported in previous studies.AIM To evaluate whether vinegar supplementation could improve the prognosis of patients with lightly stained esophageal lesions.METHODSThis prospective single-centre trial included consecutive patients with lightly stained lesions between June 2020 and April 2022.Patients in the experimental group received increased amounts of vinegar for 6 months.The primary outcome of the study was the clinical therapeutic effect.Complications related to vinegar ingestion and adverse events were also recorded in detail.RESULTS A total of 166 patients were included in the final analysis.There was no significant difference in the baseline data between the two groups.Intention-to-treat(ITT)analysis demonstrated that the rates at which endoscopic characteristics improved were 33.72%in the experimental group and 20.00%in the conventional group(P=0.007);and the rates at which biopsy pathology improved were 19.77%and 8.75%,respectively(P=0.011).Additional vinegar consumption had a statistically protective effect on the rate at which endoscopic characteristics improved[hazard ratio(HR)_(ITT)=2.183,95%CI:1.183-4.028;HR_(per-protocol(PP))=2.307,95%CI:1.202-4.426]and biopsy pathology improved(HR_(ITT)=2.931,95%CI:1.212-7.089;HR_(PP)=3.320,95%CI:1.295-8.507).No statistically significant effect of increased vinegar consumption on preventing high-grade intraepithelial neoplasia or early cancer was observed(HR_(ITT)=0.382,95%CI:0.079-1.846;HRPP=0.382,95%CI:0.079-1.846).The subgroup analyses indicated that the overall therapeutic improvement of endoscopic characteristics and biopsy pathology seemed more obvious in older(age>60)male patients with small lesions(lesion size≤0.5 cm).Three patients in the experimental group reported acid regurgitation and heartburn.No adverse event during gastroscopy were recorded during follow-up.CONCLUSION A moderately increased ingestion of vinegar could not directly reduce the risk of esophageal cancer in the mucosa dysplasia population,but it improved the endoscopic characteristics and ameliorated the biopsy pathology to a certain extent.Further research is needed to verify the effect of nutritional intervention on precancerous esophageal lesions.

Improving the Compatibility of Biodegradable Poly (Lactic Acid) Toughening with Thermoplastic Polyurethane (TPU) and Compatibilized Meltblown Nonwoven

Poly (Lactic Acid) (PLA) is a biodegradable polymer which originates from natural resources such as corn and starch, offering excellent strength, biodegradability, nevertheless its inherent brittleness and low impact resistance properties have limited its application. On the other hand, Thermoplastic Polyurethane (TPU) has high toughness, durability and flexibility, which is one of the most potential alternatives for enhancing the flexibility and mechanical strength of Poly (Lactic Acid) (PLA) by blending it with a compatibilizer. With the aim to improve the mechanical and thermal properties of Poly (Lactic Acid) (PLA) meltblown nonwovens, The Thermoplastic Polyurethane (TPU) was melt blended with Poly (Lactic Acid) (PLA) at the different corresponding proportions for toughening the Poly (Lactic Acid) and the corresponding PLA/TPU MBs (meltblown nonwovens) were also manufactured. Joncryl ADR 4400 is mixed into the PLA matrix during processing. It was found that Joncryl had a much higher chain extension that substantially increased the molecular weight of the PLA matrix. SEM study revealed that Joncryl ADR 4400 is a good compatibilizer. Moreover, in this study, the crystallization, thermal and rheological behaviors of the corresponding PLA and TPU blends were also investigated. PLA/TPU MBs were also characterized by morphology and mechanical properties. The rheological property of the PLA/TPU meltblown nonwoven revealed that the viscosity is increasing as the amount of TPU is increasing in the blend, PLA/TPU meltblown nonwovens exhibited excellent mechanical properties;they are soft, elastic, and have certain tensile strength. New materials have potential applications in the medical and agricultural fields. Joncryl ADR 4400 compatibilized blends showed higher strength than simple PLA/TPU blends at the same PLA/TPU ratio.

Preparation and promising optoelectronic applications of lead halide perovskite patterned structures:A review

Lead halide perovskites have received considerable attention from researchers over the past several years due to their superior optical and optoelectronic properties,because of which they can be a versatile platform for fundamental science research and applications.Patterned structures based on lead halide perovskites have much more novel properties compared with their more commonly seen bulk-,micro-,and nano-crystals,such as improvement in antireflection,light-scattering effects,and light absorption,as a result of their adjustability of spatial distributions.However,there are many challenges yet to be resolved in this field,such as insufficient patterned resolution,imperfect crystal quality,complicated preparation process,and so on.To pave the way to solve these problems,we provide a systematic presentation of current methods for fabricating lead halide perovskite patterned structures,including thermal imprint,use of etching films,two-step vapor-phase growth,template-confined solution growth,and seed-assisted growth.Furthermore,the advantages and disadvantages of these methods are elaborated in detail.In addition,thanks to the extraordinary properties of lead halide perovskite patterned structures,a variety of potential applications in optics and optoelectronics of these structures are described.Lastly,we put forward existing challenges and prospects in this exciting field.

Self-Supporting Nanoporous Copper Film with High Porosity and Broadband Light Absorption for Efficient Solar Steam Generation

Solar steam generation(SSG)is a potential technology for freshwater production,which is expected to address the global water shortage problem.Some noble metals with good photothermal conversion performance have received wide concerns in SSG,while high cost limits their practical applications for water purification.Herein,a self-supporting nanoporous copper(NP-Cu)film was fabricated by one-step dealloying of a specially designed Al_(98)Cu_(2)precursor with a dilute solid solution structure.In-situ and ex-situ characterizations were performed to reveal the phase and microstructure evolutions during dealloying.The NP-Cu film shows a unique three-dimensional bicontinuous ligament-channel structure with high porosity(94.8%),multi scale-channels and nanoscale ligaments(24.2±4.4nm),leading to its strong broadband absorption over the 200–2500 nm wavelength More importantly,the NP-Cu film exhibits excellent SSG performance with high evaporation rate,superior efficiency and good stability.The strong desalination ability of NP-Cu also manifests its potential applications in seawater desalination.The related mechanism has been rationalized based upon the nanoporous network,localized surface plasmon resonance effect and hydrophilicity.

利用酵母双杂交系统筛选与柑橘黄化脉明病毒CP互作的寄主因子

【目的】柑橘黄化脉明病毒(citrus yellow vein clearing virus,CYVCV)是威胁我国柑橘产业稳定发展的主要病毒,但其在柑橘上的侵染和致病机制尚不清楚。本文以CYVCV的外壳蛋白(coat protein,CP)为诱饵筛选尤力克柠檬(Citrus limon Burm.f.)c DNA文库,利用生物信息学方法分析与其互作的寄主因子在病毒侵染和致病过程中可能发挥的作用。【方法】Trizol法提取尤力克柠檬叶片总RNA,用SMART法反转录合成First-Strand c DNA,以其为模板通过Long-Distance PCR获得ds c DNA,均一化处理后与线性化p GADT7质粒重组链接构建尤力克柠檬初级c DNA文库,重组质粒转化大肠杆菌DH10B获得尤力克柠檬大肠杆菌c DNA文库并对文库质量进行鉴定;PCR扩增CYVCV的CP序列并构建到载体p GBKT7上,鉴定诱饵质粒对酵母细胞的毒性以及CP蛋白对酵母报告基因的自激活性。将尤力克柠檬c DNA文库质粒转化含有诱饵质粒p GBKT7-CP的Y2H Gold酵母菌株,共转化子依次涂布SD/-Leu-Trp、SD/-Leu-Trp-His/X-α-Gal和SD/-Leu-Trp-His-Ade/X-α-Gal平板,最终筛选蓝色且长势较好的阳性菌落,提取酵母质粒并测序比对获得候选基因,利用Uniprot在线网站的gene ontology(GO)注释候选基因,分析候选互作蛋白的生物学功能。根据分析结果,选取可能参与寄主抗病或症状发展的候选因子,扩增其CDS全长序列并构建到靶标载体p GADT7后分别与p GBKT7-CP共转化酵母细胞进行点对点酵母双杂交互作验证。【结果】尤力克柠檬大肠杆菌c DNA文库滴度为1.02×10^(8)cfu/m L,库容符合试验标准;成功构建酵母双杂交诱饵载体p GBKT7-CP,该载体没有自激活性且对酵母菌没有毒性;在SD/-Leu-Trp-His-Ade/X-α-Gal平板上筛选得到41个酵母阳性克隆,经序列相似性比对,去除重复,共筛得32个候选寄主因子;GO通路注释结果表明这些寄主因子参与多个叶绿体相关的生物过程,包括碳水化合物代谢、光合作用、光刺激反应、代谢分解和生物合成等过程;这32个寄主因子的分子功能多样,包括催化活性、水解酶活性、转移酶活性、蛋白质结合、转录因子活性和翻译因子活性等,其细胞组分涉及叶绿体、类囊体、膜、细胞质、细胞核和高尔基体等。从候选寄主因子中选取14个重要的蛋白与CP的一对一酵母双杂交验证结果表明,CP与这14个蛋白均发生互作。【结论】成功构建了尤力克柠檬c DNA文库,筛选出32个与CYVCV CP互作的尤力克柠檬寄主因子,分析重要的寄主蛋白功能,推测CYVCV CP通过与光系统Ⅱ放氧强化复合物组分蛋白(Psb P)、光系统I叶绿素结合蛋白(Lhca3)和1,5-二磷酸核酮糖羧化酶小亚基(Rbc S)等多个叶绿体相关蛋白的互作,影响光系统稳定、类囊体结构和叶绿素合成,从而导致光合作用降低以及叶绿体形态和功能受损,酵母点对点验证了CP与这些叶绿体相关因子的互作,这为揭示CYVCV CP参与病毒致病的分子机制提供了理论依据。

Artificial nerve graft constructed by coculture of activated Schwann cells and human hair keratin for repair of peripheral nerve defects

Studies have shown that human hair keratin(HHK) has no antigenicity and excellent mechanical properties. Schwann cells, as unique glial cells in the peripheral nervous system, can be induced by interleukin-1β to secrete nerve growth factor, which promotes neural regeneration. Therefore, HHK with Schwann cells may be a more effective approach to repair nerve defects than HHK without Schwann cells. In this study, we established an artificial nerve graft by loading an HHK skeleton with activated Schwann cells. We found that the longitudinal HHK microfilament structure provided adhesion medium, space and direction for Schwann cells, and promoted Schwann cell growth and nerve fiber regeneration. In addition, interleukin-1β not only activates Schwann cells, but also strengthens their activity and increases the expression of nerve growth factors. Activated Schwann cells activate macrophages, and activated macrophages secrete interleukin-1β, which maintains the activity of Schwann cells. Thus, a beneficial cycle forms and promotes nerve repair. Furthermore, our studies have found that the newly constructed artificial nerve graft promotes the improvements in nerve conduction function and motor function in rats with sciatic nerve injury, and increases the expression of nerve injury repair factors fibroblast growth factor 2 and human transforming growth factor B receptor 2. These findings suggest that this artificial nerve graft effectively repairs peripheral nerve injury.

Configuration Design and Kinematic Performance Analysis of a Novel 4-DOF Parallel Ankle Rehabilitation Mechanism with Two Virtual Motion Centers

Aiming at the problem that the existing ankle rehabilitation robot is difficult to fully fit the complex motion of human ankle joint and has poor human-machine motion compatibility,an equivalent series mechanism model that is highly matched with the actual bone structure of the human ankle joint is proposed and mapped into a parallel rehabilita-tion mechanism.The parallel rehabilitation mechanism has two virtual motion centers(VMCs),which can simulate the complex motion of the ankle joint,adapt to the individual differences of various patients,and can meet the reha-bilitation needs of both left and right feet of patients.Firstly,based on the motion properties and physiological structure of the human ankle joint,the mapping relationship between the rehabilitation mechanism and ankle joint is determined,and the series equivalent model of the ankle joint is established.According to the kinematic and con-straint properties of the ankle equivalent model,the configuration design of the parallel ankle rehabilitation robot is carried out.Secondly,according to the intersecting motion planes theory,the full-cycle mobility of the mechanism is proved,and the continuous axis of the mechanism is judged based on the constraint power and its derivative.Then,the kinematics of the parallel ankle rehabilitation robot is analyzed.Finally,based on the OpenSim biomechanical soft-ware,a human-machine coupling rehabilitation simulation model is established to evaluate the rehabilitation effect,which lays the foundation for the formulation of a rehabilitation strategy for the later prototype.

Corrigendum to“GB7 acetate,a galbulimima alkaloid from Galbulimima belgraveana,possesses anticancer effects in colorectal cancer cells”[J.Pharm.Anal.12(2022)339e349]

Original statement in Section 3.5:3.5.GB7 acetate reduced the mobility and invasion of HCT 116 cells The wound healing assay showed that GB7 acetate significantly decreased the migration area of HCT 116 cells when compared with the control group(P<0.05)(Figs.5A and B).Wound healing of 34%e43%was observed after 24 h and 48 h in untreated cancer cells,whereas 10%e21%were seen in the 100 and 150 mg/mL GB7 acetate groups.

SOFFLFM:Super-resolution optical fluctuation Fourierlight-field microscopy

Fourier light-field microscopy(FLFM)uses a microlens aray(MLA)to segment the Fourierplane of the microscopic objective lens to generate multiple two-dimensional perspective views,thereby reconstructing the threedimensional(3D)structure of the sample using 3D deconvo-lution calculation without scanning.However,the resolution of FLFM is stil limited by dif-fraction,and furthermore,it is dependent on the aperture division.In order to improve itsresolution,a super-resolution opticai fuctuation Fourier light-field microscopy(SOFFLFM)wasproposed here,in which the super-resolution optical fluctuation imaging(SOFI)with the abilityof super-resolution was introduced into FLFM.SOFFLFM uses higher-order cumulants statis-tical analysis on an image sequence collected by FLFM,and then carries out 3D deconvolutioncalculation to reconstruct the 3D structure of the sample.The theoretical basis of SOFFLFM onimproving resolution was explained and then verified with the simulations.Simulation resultsdemonstrated that SOFFLFM improved the lateral and axial resolution by more than V2 and 2times in the second-and fourth-order accumulations,compared with that of FLFM.

Global pattern and determinants of coronavirus disease 2019(COVID-19)vaccine coverage and progression:a global ecological study

Background:Understanding and minimizing existing global coronavirus disease 2019(COVID-19)vaccination disparities is critical to global population health and eliminating health inequities.The study aims to investigate the disparities of vaccination coverage and progression and the associated economic and educational determinants to inform global COVID-19 vaccination strategies.Methods:COVID-19 vaccination coverage data from 206 countries used in the study were derived from“Our World in Data”website.After obtaining the vaccination coverage indicators,we fitted the progression indicators for vaccination.Correlation and multiple linear regression analysis were used to examine the effects of gross domestic product(GDP)per capita,Gini index,education,and their interactions on the coverage and progression of the COVID-19 vaccination.Results:The coverage of COVID-19 vaccination ranged from less than 30 doses to more than 150 doses per hun­dred people,from less than 15%to more than 75%for proportion of people vaccinated,from less than 15%to more than 60%for proportion of people fully vaccinated.Similarly,the progression of vaccination ranged from less than 0.1 to more than 0.6 for progression of total number of doses,from less than 0.1 to more than 0.3 for progression of proportion of people vaccinated,and from less than 0.1 to more than 0.4 for progression of propor­tion of people fully vaccinated.GDP per capita and education were positively associated with the coverage and progression,while Gini index was negatively associated with the coverage and progression.Negative interaction between GDP per capita and education was also observed for coverage(0=-0.012 to-0.011,P<0.05)and progression(0=-0.012 to-0.011,P<0.05).Conclusions:Substantial geographic disparities existed for the coverage and progression of COVID-19 vaccination.

“化学在抗击新冠肺炎疫情中扮演的重要角色”专题教学

结合当前新冠病毒肺炎疫情防控工作,挖掘并凝练化学消毒剂、临床治疗或试验的典型药物、医用防护用品的加工材料等教学素材,开展了"化学在抗击新冠肺炎疫情中扮演的重要角色"专题教学,实现了专题教学与思政教育有机融合。通过专题教学,使学生深刻领略到化学学科的魅力,激发学生学习化学的兴趣,充分调动学生的学习积极性和主动性,增强学生战胜困难的信心和勇气,培养学生的学科素养、职业素养和科学素养,激发学生热爱祖国、热爱人民、热爱中国共产党的思想情感。

An Energy Efficiency Assessment Method for Distribution Network Containing DG

Energy efficiency assessment of distribution network containing distributed generation is one of the core contents of power grid construction. Aiming at the lack of a quantitative evaluation method for energy efficiency of distribution network containing distributed generation, a novel energy efficiency assessment method based on the super-efficiency model is proposed. Starting from the basic elements and operational requirements of the distribution network containing distributed generation, the energy efficiency assessment metric set is constructed. On this basis, the concept of generalized energy efficiency function is defined, and the super-efficiency model is used to assess the energy efficiency of the distribution network containing distributed generation. Finally, an example is given to evaluate and analyze energy efficiency. The results confirm the validity of the proposed method.

氧化石墨烯的表面改性及对尼龙6纤维的力学增强作用

为了提高尼龙6(PA6)纤维的力学性能,利用十二烷基胺(DA)对氧化石墨烯(GO)表面改性得到氨基化的氧化石墨烯(A-GO),将A-GO与PA6熔融共混纺丝制得A-GO/PA6复合纤维。通过对A-GO及A-GO/PA6复合纤维的结构表征,结果表明DA成功接枝于GO,相较于未改性的GO,A-GO的层间距增大了0.37nm,改性的A-GO与基体PA6具有良好的界面相互作用,可以实现较为均匀的分散;A-GO在PA6纤维中起异相成核作用,促进了尼龙6纤维的结晶,并诱导PA6由α晶型向γ晶型转变;A-GO/PA6复合纤维较纯PA6纤维的5%热失重温度提高了6.1~8.9℃,表现出更高的热稳定性;当A-GO的含量仅为0.1%时,复合纤维的拉伸强度是纯PA6纤维的1.4倍。

自黏性锆基金属有机框架材料在重铬酸根离子吸附中的应用

为解决金属有机框架材料(MOFs)粉体在处理重金属离子水体时易团聚、难回收、易二次污染的问题,文中提出将自黏性MOFs负载于非织造布上制备复合材料。利用聚氨酯低聚物对锆基MOFs(UiO-66-NH_(2))进行接枝改性,获得自黏性锆基有机框架材料(Adh-UiO-66-NH_(2)),分析改性前后MOFs的晶型和形貌变化;经浸轧-焙烘将Adh-UiO-66-NH_(2)负载于PET非织造布上得到Adh-UiO-66-NH_(2)@PET非织造布复合材料,观测复合材料的形貌、亲疏水性和水通量,探究其对重铬酸根离子(Cr_(2)O_(7)^(2-))的吸附性能。结果表明:聚氨酯低聚物与UiO-66-NH_(2)以共价键方式结合制得Adh-UiO-66-NH_(2),但其仍保留原有的晶型,MOFs粒子均匀分散于聚氨酯基体中;经后整理后,Adh-UiO-66-NH_(2)以成膜的形式将非织造布纤维包裹,复合材料的亲水性相较纯PET非织造布亲水性增强且水通量增大;K 2Cr 2O 7水溶液经复合材料过滤后,颜色由淡黄色变至透明,Cr_(2)O_(7)^(2-)的紫外吸收峰明显变弱,且复合材料具有良好的可重复利用性,经5次连续的吸附-解吸-吸附工序,仍对Cr_(2)O_(7)^(2-)表现出良好的吸附性。

ZIF-8@PAN纳米纤维膜基多孔碳材料的制备及对镉离子的吸附性能

主要将通过磁控溅射技术制备所得的氧化锌@聚丙烯腈(ZnO@PAN)静电纺丝纳米纤维膜材料,利用溶剂热反应合成金属有机框架材料ZIF-8@聚丙烯腈(ZIF-8@PAN)纳米纤维膜材料,后经过900℃高温煅烧工序制备ZIF-8@PAN纳米纤维膜基多孔碳材料,并将其应用于水体中重金属离子镉的吸附。X射线衍射、红外光谱、扫描电镜分析表征结果表明,ZIF-8成功地在PAN纳米纤维膜上原位生长,经过高温煅烧,ZIF-8的结构并未明显改变。ZIF-8@PAN纳米纤维膜基多孔碳材料在水溶液中对镉离子具有良好的吸附效果。探究证明,吸附过程中,在溶液为中性条件下,且水浴加热35℃时,镉离子吸附效果最好,吸附效率最高可达到88%左右。