Fungal community structure analysis of peanut pod rot in soil in Hebei Province,China

In recent years,peanut yield and quality are more seriously affected by pod rot disease in China.However,managing this disease has proven challenging due to the wide host range of its pathogens.In this study,four soil samples were collected from fields with pod rot disease in Hebei Province,and 454 pyrosequencing was used to analyze the fungal communities structure within them.All 38490 ITS high-quality sequences were grouped into 1203 operational taxonomic units,the fungal community diversity of four soil samples was evaluated and compared using Shannon index and Simpson index.The results showed that members of Ascomycota were dominant,followed by Basidiomycota.According to the BLAST results at the species level,Guehomyces had the highest abundance,accounting for about 7.27%,followed by Alternaria,Fusarium,and Davidiella.The relative abundance of Fusarium oxysporum isolated from rotting peanuts in soil with peanut rot was higher than that in the control,indicating that Fusarium oxysporum might be one of the main pathogenic fungus of peanut rot in this area.This study delved into the broader fungal community associated with peanut pod rot,providing a theoretical foundation for preventing and treating this disease in agriculture.

溴掺杂石墨相碳化氮对Cr(Ⅵ)光催化还原性能的提高

半导体光催化技术不仅可将太阳能转化为化学能,还能直接降解和矿化有机污染物,在解决能源短缺和治理环境污染等方面具有广阔的应用前景.然而传统的TiO2光催化剂具有较大的禁带宽度(3.2 eV),使得材料只能吸收紫外光(仅占太阳光的4%)且量子产率较低.因此,研究和开发新型的本身具有可见光响应的光催化材料在实际应用中具有重要的指导意义.g-C3N4作为一种非金属有机聚合物n型半导体,因具有合适的禁带宽度、独特的电子结构和良好的化学稳定性,迅速成为光催化领域的研究热点.但是,由于g-C3N4本身存在比表面积小、可见光响应范围狭窄和光生电子-空穴对分离效率低等缺陷,极大限制了其光催化实际应用.为了解决该问题,人们进行了很多尝试来改善石墨相氮化碳光催化材料的光催化活性.研究表明,非金属元素掺杂是一种有效且常用的提高g-C3N4光催化性能的方法.例如,通过高温煅烧三聚氰胺和氧化硼混合物可制备掺B的g-C3N4,g-C3N4结构中的H元素被B取代, B的掺杂大大提高了g-C3N4的光催化活性;利用氟化铵和三聚氰胺合成F掺杂的g-C3N4, F原子与g-C3N4中心或边缘的C键合,将部分sp2杂化的碳原子转化为sp3杂化,降低了材料的平面性,从而使材料的析氢性能和催化苯氧化生成苯酚的能力有了明显提高;使用氯化铵和双氰胺作为前驱体制备Cl掺杂的g-C3N4, Cl元素的引入使g-C3N4晶格变形,带隙变窄,电荷迁移效率提高,光催化效率显著改善.基于上述结果,并考虑到原子的电负性和大小等因素的影响,我们采用简单的一步法合成了系列Br掺杂的g-C3N4光催化剂CN–BrX.通过X射线衍射(XRD)、红外光谱(FTIR)和电子显微镜(SEM、TEM)等手段对材料的结构进行了表征,并结合元素分析(EA)和光电子能谱(XPS)研究了其形成机理.采用光催化还原Cr(VI)效率、光催化产双氧水浓度以及光催化氧化NO能力评价了CN–BrX的光催化活性,并进行了光催化反应过程动力学拟合和循环实验.通过理论计算(DFT)、紫外-可见漫反射光谱(UV-vis DRS)、荧光光谱(PL)、光电流(PC)和比表面积(BET)等测试分析了材料的光催化活性增强机理,并通过活性物种捕获实验深入探究了其光催化还原Cr(VI)的反应机理.结果表明, CN–BrX(CN–Br30除外)保留了g-C3N4的基本骨架,其中Br元素以取代碳氮杂环中N原子的形式均匀分布于g-C3N4结构中.引入的Br元素可以明显降低材料的禁带宽度,拓宽其可见光响应范围,加快光生载流子的分离效率,并增大其比表面积,从而使得改性材料具有更高的光催化氧化还原活性.此外,在Cr(VI)光催化还原过程中,光生e-,·OH和H2O2均起着重要作用.

水质采样专用多旋翼无人机及其控制系统

针对环境保护部门等用户对水质采样专用无人机的需求和具体要求,本文设计了水质采样专用四旋翼无人机,分别从无人机的部件、采水装置、电路模块等硬件设备,以及控制算法、采样流程等软件方面进行介绍.本文在四旋翼无人机动力学模型基础上,加入对水流冲击力的分析,设计四旋翼无人机的飞行采样模式,并对其有效性与实用性进行仿真测试与实践验证,完成了水质采样专用四旋翼无人机的手动采样与自动采样过程.

基于非均匀连续时间马尔可夫原理的海上浮式风机齿轮箱最优维修策略研究（英文）

Gearbox in offshore wind turbines is a component with the highest failure rates during operation. Analysis of gearbox repair policy that includes economic considerations is important for the effective operation of offshore wind farms. From their initial perfect working states, gearboxes degrade with time, which leads to decreased working efficiency. Thus, offshore wind turbine gearboxes can be considered to be multi-state systems with the various levels of productivity for different working states. To efficiently compute the time-dependent distribution of this multi-state system and analyze its reliability, application of the nonhomogeneous continuous-time Markov process(NHCTMP) is appropriate for this type of object. To determine the relationship between operation time and maintenance cost, many factors must be taken into account, including maintenance processes and vessel requirements. Finally, an optimal repair policy can be formulated based on this relationship.

Toxic Effects of Nano-CuO, Micro-CuO and Cu²⁺on <i>Chlorella</i>sp.

The 96 h acute toxic effects of nano-CuO (N-CuO), micro-CuO (M-CuO) and 2+ on Chlorella sp. were investigated in this paper. The results showed that toxicities decreased in an order of Cu2+>N-CuO>M-CuO. The 96 h EC50 of Cu2+ on Chlorella sp. was 1.06 mg /L, and of N-CuO it was 74.61 mg /L, while no pronounced toxicity was observed when the concentration of M-CuO was lower than 160 mg/L. Further experiments were carried out in order to study the toxicity mechanism of nano-CuO on Chlorella sp.. The results of Cu2+ release from N-CuO showed less than 0.2 mg/L Cu2+ were released, so the release of Cu2+ was not responsible for the toxicity. Further experiments showed N-CuO inhibited formation of Chlorophyll A. Content of Chlorophyll A in the control group was 4.75 mg/108 cells, while it declined to 2.89 mg/108 cells for 160 mg/L N-CuO after 96 h, which indicated that N-CuO could inhibit photosynthesis of Chlorella sp.. Moreover, N-CuO condensed with algal cells. It affected the activity of SOD and POD, indicating that N-CuO could cause oxidant stress to Chlorella sp.. These may be the toxicity mechanism.

Impact of mTOR gene polymorphisms and gene-tea interaction on susceptibility to tuberculosis

BACKGROUND mTOR gene is a key component of the PI3K/Akt/mTOR signaling pathway,and its dysregulation is associated with various diseases.Several studies have demonstrated that tea drinking is a protective factor against tuberculosis(TB).This study was designed to explore five single nucleotide polymorphisms(SNPs)of mTOR in the Han population of China to determine how their interactions with tea drinking affect susceptibility to TB.AIM To investigate if the polymorphisms of mTOR gene and the gene-tea interaction are associated with susceptibility to TB.METHODS In this case-control study,503 patients with TB and 494 healthy controls were enrolled by a stratified sampling method.The cases were newly registered TB patients from the county-level centers for disease control and prevention,and the healthy controls were permanent residents from Xin'ansi Community,Changsha city.Demographic data and environmental exposure information including tea drinking were obtained from the study participants.We genotyped five potentially functional SNP sites(rs2295080,rs2024627,rs1057079,rs12137958,and rs7525957)of mTOR gene and assessed their associations with the risk of TB using logistic regression analysis,and marginal structural linear odds models were used to estimate the gene-environment interactions.RESULTS The frequencies of four SNPs(rs2295080,rs2024627,rs1057079,and rs7525957)were found to be associated with susceptibility to TB(P<0.05).Genotypes GT(OR 1.334),GG(OR 2.224),and GT+GG(OR 1.403)at rs2295080;genotypes CT(OR 1.562)and CT+TT(OR 1.578)at rs2024627,genotypes CT(OR 1.597),CC(OR 2.858),and CT+CC(OR 1.682)at rs1057079;and genotypes CT(OR 1.559)and CT+CC(OR 1.568)at rs7525957 of mTOR gene were significantly more prevalent in TB patients than in healthy controls.The relative excess risk of interaction between the four SNPs(rs2295080,rs2024627,rs1057079,and rs7525957)of mTOR genes and tea drinking were found to be-1.5187(95%CI:-1.9826,-1.0547,P<0.05),-1.8270(95%CI:-2.3587,-1.2952,P<0.05),-2.3246(95%CI:-2.9417,-1.7076,P<0.05)and-0.4235(95%CI:-0.7756,-0.0714,P<0.05),respectively,which suggest negative interactions.CONCLUSION The polymorphisms of mTOR(rs2295080,rs2024627,rs1057079,and rs7525957)are associated with susceptibility to TB,and there is a negative interaction between each of the four SNPs and tea drinking.

Numerical investigations of fully nonlinear water waves generated by moving bottom topography

This paper is concerned with propagation of water waves induced by moving bodies with uniformvelocity on the bottom of a channel, a simple model for prescribed underwater landslides. Thefluid is assumed to be inviscid and incompressible, and the flow, irrotational. We apply this modelto a variety of test problems, and particular attention is paid to long-time dynamics of wavesinduced by two landslide bodies moving with the same speed. We focus on the transcritical regimewhere the linear theory fails to depict the wave phenomena even in the qualitative sense since itpredicts an infinite growth in amplitude. In order to resolve this problem, weakly nonlinear theoryor direct numerical simulations for the fully nonlinear equations is required. Comparing results ofthe linear full-dispersion theory, the linear shallow water equations, the forced Korteweg-de Vriesmodel, and the full Euler equations, we show that water waves generated by prescribedunderwater landslides are characterized by the Froude number, sizes of landslide bodies anddistance between them. Particularly, in the transcritical regime, the second body plays a key role incontrolling the criticality for equal landslide bodies, while for unequal body heights, the higher onecontrols the criticality. The results obtained in the current paper complement numerical studiesbased on the forced Korteweg-de Vries equation and the nonlinear shallow water equations byGrimshaw and Maleewong (J. Fluid Mech. 2015, 2016).

In vitro 3D malignant melanoma model for the evaluation of hypericin-loaded oil-in-water microemulsion in photodynamic therapy

Advances in biomimetic three-dimensional(3D) melanoma models have brought new prospects of drug screening and disease modeling, since their physiological relevancy for recapitulating in vivo tumor architectures is more accurate than traditional two-dimensional(2D) cell culture. Gelatin methacryloyl(GelMA) is widely used as a tissue-engineered scaffold hydrogel for 3D cell culture. In the present study, an in vitro 3D malignant melanoma model based on Gel MA was fabricated to evaluate the efficiency of hypericin(Hy)-loaded microemulsion(ME) in photodynamic therapy against melanoma. The ME was produced by the spontaneous emulsification method to enhance the bioavailability of Hy at tumor sites. Hy-loaded MEs were applied to a 3D malignant melanoma model made using 6% Gel MA and the co-culture of B16F10 and Balb/c 3T3 cells,followed by crosslinking using violet light(403 nm). The observation revealed excellent cell viability and the presence of F-actin cytoskeleton network. Hy-loaded MEs exhibited higher phototoxicity and cell accumulation(about threefold) than free Hy, and the cells cultured in the 3D system displayed lower susceptibility(about 2.5-fold) than those in 2D culture.These findings indicate that the developed MEs are potential delivery carriers for Hy;furthermore, Gel MA hydrogel-based modeling in polydimethylsiloxane(PDMS) molds is a user-friendly and cost-effective in vitro platform to investigate drug penetration and provide a basis for evaluating nanocarrier efficiency for skin cancer and other skin-related diseases.

Evaluation of SRAP markers efficiency in genetic diversity of Aspergillus flavus from peanut-cropped soils in China

In order to evaluation the efficiency of SRAP markers on genetic diversity of Aspergillus flavus,we screened out 17sets of primer pairs which could produce clear and reproducible SRAP bands from 150 SRAP primer pairs.The size of SRAP fragments ranged from 120 to 2100 bp.Primer pair Me10/Em9 produced the maximum number of polymorphic bands(12 bands),while Me8/Em13 produced the fewest number of polymorphic bands(only 1).Through analysis genetic diversity ability of different sets of primer pairs,the set of 12 primer pairs was selected for SRAP genetic marker of A.flavus.Cluster analysis was performed based on the genetic similarity coefficients,which ranged from 0.53 to 0.89.A dendrogram assembled using the unweighted pair-group method with arithmetic averages grouped A.flavus samples into 5 main clusters.The results suggested that SRAP marker is a useful molecular technology for the diversity of A.flavus from peanut soils in China.

基于3D受限自组装构筑中空介孔氧化硅/碳复合微球

发展简单、高效、可控的方法来制备中空介孔微球是介孔材料领域的研究热点.本工作结合嵌段共聚物的三维受限自组装(3D-CSA)和自模板碳化策略,建立了一种构筑中空介孔微球的新方法.首先,采用乳液-溶剂挥发法实现嵌段共聚物与全氟辛烷(PFO)在3D受限空间的分级组装,获得了核-壳结构微球,其中壳层由微相分离的嵌段共聚物构成.然后,在壳层的连续相选择性地复合氧化硅,既实现了无机框架的负载,又实现了对连续相聚合物链选择性交联.对复合微球进行煅烧处理后,实现了壳层连续相聚合物的选择性碳化,获得了中空介孔氧化硅/碳复合微球.本研究系统地阐述了核-壳型分级结构微球的形成机理和必备条件,研究了氧化硅前驱体添加量和嵌段共聚物分子量对中空介孔氧化硅/碳复合微球形貌的影响,为制备中空介孔微球材料提供了一种简便、可控的方法.

Dispersion-less Kerr solitons in spectrally confined optical cavities

Solitons are self-reinforcing localized wave packets that manifest in the major areas of nonlinear science,from optics to biology and Bose-Einstein condensates.Recently,optically driven dissipative solitons have attracted great attention for the implementation of the chip-scale frequency combs that are decisive for communications,spectroscopy,neural computing,and quantum information processing.In the current understanding,the generation of temporal solitons involves the chromatic dispersion as a key enabling physical effect,acting either globally or locally on the cavity dynamics in a decisive way.Here,we report on a novel class of solitons,both theoretically and experimentally,which builds up in spectrally confined optical cavities when dispersion is practically absent,both globally and locally.Precisely,the interplay between the Kerr nonlinearity and spectral filtering results in an infiinite hierarchy of eigenfunctions which,combined with optical gain,allow for the generation of stable dispersion-less dissipative solitons in a previously unexplored regime.When the filter order tends to infinity,we find an unexpected link between dissipative and conservative solitons,in the form of Nyquist-pulse-like solitons endowed with an ultra-flat spectrum.In contrast to the conventional dispersion-enabled nonlinear Schr?dinger solitons,these dispersion-less Nyquist solitons build on a fully confined spectrum and their energy scaling is not constrained by the pulse duration.Dispersion-less soliton molecules and their deterministic transitioning to single solitons are also evidenced.These findings broaden the fundamental scope of the dissipative soliton paradigm and open new avenues for generating soliton pulses and frequency combs endowed with unprecedented temporal and spectral features.

High-density lipoprotein regulates angiogenesis by long non-coding RNA HDRACA

Normal high-density lipoprotein(nHDL)can induce angiogenesis in healthy individuals.However,HDL from patients with coronary artery disease undergoes various modifications,becomes dysfunctional(dHDL),and loses its ability to promote angiogenesis.Here,we identified a long non-coding RNA,HDRACA,that is involved in the regulation of angiogenesis by HDL.In this study,we showed that nHDL downregulates the expression of HDRACA in endothelial cells by activating WW domain-containing E3 ubiquitin protein ligase 2,which catalyzes the ubiquitination and subsequent degradation of its transcription factor,Kruppel-like factor 5,via sphingosine 1-phosphate(S1P)receptor 1.In contrast,dHDL with lower levels of S1P than nHDL were much less effective in decreasing the expression of HDRACA.HDRACA was able to bind to Ras-interacting protein 1(RAIN)to hinder the interaction between RAIN and vigilin,which led to an increase in the binding between the vigilin protein and proliferating cell nuclear antigen(PCNA)mRNA,resulting in a decrease in the expression of PCNA and inhibition of angiogenesis.The expression of human HDRACA in a hindlimb ischemia mouse model inhibited the recovery of angiogenesis.Taken together,these findings suggest that HDRACA is involved in the HDL regulation of angiogenesis,which nHDL inhibits the expression of HDRACA to induce angiogenesis,and that dHDL is much less effective in inhibiting HDRACA expression,which provides an explanation for the decreased ability of dHDL to stimulate angiogenesis.

Asymmetric Mesoporous Carbon Microparticles by 3D-Confined Self-Assembly of Block Copolymer/Homopolymer Blends and Selective Carbonization

Shape control of mesoporous carbon microparticles(MCMPs)is of critical importance;in particular,asymmetric shapes that can yield unique properties have attracted significant attention.However,the tailored synthesis of asymmetric MCMPs with ordered structures remains challenging.Herein,we report a facile route to prepare asymmetric MCMPs by dynamic neutral interface-guided 3D-confined self-assembly(3D-CSA)of block copolymer/homopolymer(BCP/hP)blends,followed by a self-templated selective direct carbonization strategy.BCP/h P Janus microparticles with ordered hierarchical mesostructures were prepared with emulsion solvent evaporation-induced 3D-CSA.The continuous phase of BCP domains was then crosslinked.Composite asymmetric MCMPs are successfully generated after selective carbonization of the crosslinked continuous phase.This method allows tuning the shape of MCMPs easily by varying the blending ratio of BCP/h P.The composite asymmetric MCMPs combine the advantages of asymmetric shape,ordered structure,high specific surface area,chemical inertness and thermal stability and could provide great possibilities for applications in catalysis,drug delivery,energy conversion and storage.

Advances in coastal ocean boundary layer detection technology and equipment in China

Accurate and comprehensive knowledge of the atmospheric environment and its evolution within the coastal ocean boundary layer are necessary for understanding the sources,chemical mechanisms,and transport processes of air pollution in land,sea,and atmosphere.We present an overview of coastal ocean boundary layer detection technology and equipment in China and summarize the progress and main achievements in recent years.China has developed a series of coastal ocean boundary layer detection technologies,including Light Detection and Ranging(LIDAR),turbulent exchange analyzer,air-sea flux analyzer,stereoscopic remote sensing of air pollutants,and oceanic aerosol detection equipment to address the technical bottleneck caused by harsh environmental conditions in coastal ocean regions.Advances in these technologies and equipment have provided scientific assistance for addressing air pollution issues and understanding land-sea-atmosphere interactions over coastal ocean regions in China.In the future,routine atmospheric observations should cover the coastal ocean boundary layer of China.

Wastewater surveillance provides 10-days forecasting of COVID-19 hospitalizations superior to cases and test positivity:A prediction study

Background:The public health response to COVID-19 has shifted to reducing deaths and hospitalizations to prevent overwhelming health systems.The amount of SARS-CoV-2 RNA fragments in wastewater are known to correlate with clinical data including cases and hospital admissions for COVID-19.We developed and tested a predictive model for incident COVID-19 hospital admissions in New York State using wastewater data.Methods:Using county-level COVID-19 hospital admissions and wastewater surveillance covering 13.8 million people across 56 counties,we fit a generalized linear mixed model predicting new hospital admissions from wastewater concentrations of SARS-CoV-2 RNA from April 29,2020 to June 30,2022.We included covariates such as COVID-19 vaccine coverage in the county,comorbidities,demographic variables,and holiday gatherings.Findings:Wastewater concentrations of SARS-CoV-2 RNA correlated with new hospital admissions per 100,000 up to ten days prior to admission.Models that included wastewater had higher predictive power than models that included clinical cases only,increasing the accuracy of the model by 15%.Predicted hospital admissions correlated highly with observed admissions(r¼0.77)with an average difference of 0.013 hospitalizations per 100,000(95%CI¼[0.002,0.025])Interpretation:Using wastewater to predict future hospital admissions from COVID-19 is accurate and effective with superior results to using case data alone.The lead time of ten days could alert the public to take precautions and improve resource allocation for seasonal surges.

Kinetically Controlled Supramolecular Block Copolymer Self-Assembly:Multicolor Photonic Crystal Patterns from a Single Formulation

Photonic crystal(PC)patterns with tunable and changeable nonvolatile structural colors printed from a single ink are of great interest for optical products but have rarely been reported because most inks can only output one respective structural color.Herein,we propose a facile yet effective kinetically controlled self-assembly strategy to address this challenge.An ink formulation containing supramolecular block copolymers(SBCPs)is developed.SBCP patterns were printed by direct-ink-writing followed by solvent annealing to generate different structural colors by simply controlling the annealing time.The self-assembly kinetic regime suggests that different colors result from various kinetically trapped metastable states.In turn,the variation in structural color enables“visualization”of the self-assembly dynamics.Furthermore,we demonstrate that these kinetically trapped structures exhibit different responsive color-change behaviors.In addition,this kinetic control strategy can be synergistic with thermodynamic control to extend the color range.This study provides a facile yet effective solution for well-designed PC patterns with tunable,responsive,and unfading colors printed from the simplest single-nozzle printer with a single colorless ink,presenting great potential in broad applications,including information storage,encryption,and anti-fake.

Digital light processing (DLP)-based (bio)printing strategies for tissue modeling and regeneration

Digital light processing(DLP)-based bioprinting technology has recently aroused considerable concerns as a strategy to deliver biomedical materials and/or specific cells to create sophisticated structures for various tissue modeling and regeneration.In this review,we display a concise introduction of DLP bioprinting,and a further discussion on the design and manufacture of DLP(bio)printer with varied bioinks and their biomedical applications toward drug screening,disease modeling,tissue repair,and regenerative medicine.Finally,the advantages,challenges,and perspectives of the DLP printing platforms are detailed.It is believed that DLP bioprinting will play a decisive role in the field of tissue model and regenerative medicine,mainly due to its time-efficient,higher resolution,and amenability to automation for various tissue needs.

Frequency domain based DC fault analysis for bipolar HVDC grids

This paper proposes a frequency domain based methodology to analyse the influence of High Voltage Direct Current(HVDC) configurations and system parameters on the travelling wave behaviour during a DC fault. The method allows us to gain deeper understanding of these influencing parameters. In the literature, the majority of DC protection algorithms essentially use thefirst travelling waves initiated by a DC fault for fault discrimination due to the stringent time constraint in DC grid protection. However, most protection algorithms up to now have been designed based on extensive time domain simulations using one specific test system. Therefore, general applicability or adaptability to different configurations and system changes is not by default ensured, and it is difficult to gain in-depth understanding of the influencing parameters through time domain simulations. In order to analyse the first travelling wave for meshed HVDC grids, voltage and current wave transfer functions with respect to the incident voltage wave are derived adopting Laplace domain based component models. The step responses obtained from the voltage transfer functions are validated by comparison against simulations using a detailed model implemented in PSCADTM. Then, the influences of system parameters such as the number of parallel branches, HVDC grid configurations and groundings on the first travelling wave are investigated by analysing the voltage and current transfer functions.

节段性小肠移植手术中采用自体髂内血管进行血管重建

背景:本研究旨在评估自体髂内动静脉可否用于异体及自体节段性小肠移植手术的血管重建。方法:2011年1月至2019年1月间34例小肠移植患者纳入研究,其中19例为亲属活体移植,15例为自体移植。收集患者临床资料、血管重建类型及术后并发症进行分析。结果:全组男性20例,女性14例,中位年龄35岁。在34例小肠移植中,22例(64.7%,其中异体移植和自体移植各11例)采用自体髂内动脉脉进行血管重建,12例(35.3%)直接行血管吻合。血管重建耗时(21˘6)min。与直接吻合组相比,血管重建组患者手术总时长(530˘226 vs 440˘116 min,P=0.208)和冷缺血时间(159˘49 vs 125˘66 min,P=0.097)均有延长的趋势,但差异并未达到统计学意义。直接吻合组术后血栓形成发生率较血管重建组有增高的趋势(16.7%vs 0%,P=0.118)。中位随访36.9个月,无一例出现静脉狭窄或假性动脉瘤。19例异体移植患者中,4例(21.1%)发生急性排斥反应,1例(5.2%)出现慢性排斥反应。结论:本组数据显示,采用自体髂内动静脉进行血管重建可有力促进小肠移植的开展,同时有望降低术后血管并发症的风险。

Preparation of polyacrylamide/silica composite capsules by inverse Pickering emulsion polymerization

Polyacrylamide/silica （PAM/SiO2） composite capsules were synthesized by inverse Pickering emulsion polymerization. Silica nanoparticles modified with methacryloxypropyltrimethoxysilane （MPS） were used as a stabilizer. Transmission electron microscopy （TEM）, scanning electron microscopy （SEM）. Fourier transform infrared （FTIR） spectroscopy, and thermal gravimetric analysis （TGA） were used to characterize the morphology and composition of the composite capsules. SEM and TEM images showed that capsules consisted of a particle shell and a polymer inner layer. The capsule size depends on the nanoparticle concentration in the continuous phase. The composite rigidity largely depends on the acrylamide concentration. FTIR and TGA results indicated the existence of polyacrylamide and SiO2 in the composite particles. Aqueous Hg（ll） removal testing by the PAM/SiO2 composite capsules indicated promising potential for removing heavy metal ions from wastewater.