Study of the Diffusion Behavior of Seawater Absorption in Multi-Walled Carbon Nanotubes/Halloysite Nanotubes Hybrid Nanofillers Modified Epoxy-Based Glass/Carbon Fiber Composites

In the maritime industry, cost-effective and lightweight Fiber Reinforced Polymer (FRP) composites offer excellent mechanical properties, design flexibility, and corrosion resistance. However, their reliability in harsh seawater conditions is a concern. Researchers address this by exploring three approaches: coating fiber surfaces, hybridizing fibers and matrices with or without nanofillers, and interply rearrangement. This study focuses on evaluating the synergistic effects of interply rearrangement of glass/carbon fibers and hybrid nanofillers, specifically Multi-walled carbon nanotubes (MWCNT) and Halloysite nanotubes (HNT). The aim is to enhance impact properties by minimizing moisture absorption. Hybrid nanocomposites with equal-weight proportions of two nanofillers: 0 wt.%, 1 wt.%, and 2 wt.% were exposed to seawater for 90 days. Experimental data was subjected to modelling through the application of Predictive Fick’s Law. The study found that the hybrid composite containing 2 wt.% hybrid nanofillers exhibited a 22.10% increase in impact performance compared to non-modified counterparts. After 90 days of seawater aging, the material exhibited enhanced resistance to moisture absorption (15.74%) and minimal reduction in impact strength (8.52%) compared to its dry strength, with lower diffusion coefficients.

静电纺丝HNTs/PBST复合纳米纤维膜的制备及其空气过滤性能研究

采用静电纺丝工艺,以可生物降解的聚丁二酸丁二醇-共-对苯二甲酸丁二醇酯(PBST)为原料,改性埃洛石纳米管(HNTs)为驻极体,制备了HNTs/PBST复合纳米纤维膜,探讨了HNTs对PBST纳米纤维膜的形貌、结构及空气过滤性能的影响。实验结果表明,改性HNTs添加量为10%(w)即可使PBST纳米纤维直径细化,协同增强了纳米纤维膜的物理筛分效应及静电吸引能力,显著提升了材料的综合过滤性能,HNTs/PBST复合纳米纤维膜对PM0.3的过滤效率高达96.67%,且过滤阻力仅为90.5 Pa。

GOx@Fe_(3)O_(4)-HNTs微囊反应器的构筑及多酶级联催化性能

细胞内或细胞间的微空间使得生物体内的各种酶促反应能够高效有序地进行.基于此,本文结合天然酶-纳米酶二者的优势,构筑了一种模拟体内酶促级联反应的微囊反应器.首先,以天然硅铝酸盐矿物埃洛石纳米管(HNTs)为载体,在其表面原位生成具有类辣根过氧化物酶活性的四氧化三铁(Fe3O4);随后,将其作为囊壁材料封装天然葡萄糖氧化酶(GOx),构筑GOx@Fe3O4-HNTs微囊反应器.当向体系中加入葡萄糖时,微囊反应器内的GOx先将葡萄糖转化为葡萄糖酸和过氧化氢(H_(2)O_(2)),之后H_(2)O_(2)继续被囊壁中的Fe_(3)O_(4)催化转化为羟基自由基,触发底物3,3',5,5'-四甲基联苯胺(TMB)显色.其中,Fe_(3)O_(4)-HNTs作为囊壁材料不仅使囊内GOx免受外界环境干扰,还可与GOx构建级联催化反应体系,这种酶-纳米酶微囊化级联体系具有比天然酶系统更优异的催化性能和反应稳定性.此外,因磁性Fe_(3)O_(4)的参与,材料还具有可回收性和重复使用性.这种酶-纳米酶复合微囊反应器为模拟生物体内限域环境下的多酶反应体系提供了新方法,同时为后续生物分析与仿生催化领域的进一步研究奠定了基础.

In-situ incorporation of halloysite nanotubes with 2D zeolitic imidazolate framework-L based membrane for dye/salt separation

Layered assembled membranes of 2D leaf-like zeolitic imidazolate frameworks(ZIF-L)nanosheets have received great attention in the field of water treatment due to the porous structure and excellent antibacterial ability,but the dense accumulation on the membrane surface and the low permeate flux greatly hinder their application.Herein,we synthesized m HNTs(modified halloysite nanotubes)/ZIF-L nanocomposites on modified m HNTs by in situ growth method.Interestingly,due to the different size of m HNTs and ZIF-L,m HNTs were packed in ZIF-L nanosheets.The hollow m HNTs provided additional transport channels for water molecules,and the accumulation of the ZIF-L nanosheets was decreased after assembling m HNTs/ZIF-L nanocomposites into membrane by filtration.The prepared m HNTs/ZIF-L membrane presented high permeate flux(59.6 L·m^(-2)·h^(-1)),which is 2-4 times of the ZIF-L membranes(14.8 L·m^(-2)·h^(-1)).Moreover,m HNTs/ZIF-L membranes are intrinsically antimicrobial,which exhibit extremely high bacterial resistance.We provide a controllable strategy to improve 2D ZIF-L assembles,and develops novel membranes using 2D package structure as building units.

CEOs/HNTs/PBAT复合薄膜的制备及其性能研究

为了延长食品的货架期和减少白色污染,利用埃洛石纳米管(HNTs)负载肉桂精油(CEOs)得到CEOs/HNTs纳米粒子。将其添加到聚己二酸/对苯二甲酸丁二醇酯(PBAT)树脂中,进行熔融共混挤出,制备出具有抗菌效果的复合薄膜。热重分析表明HNTs对CEOs的初始负载率约为10%;场发射扫描电子显微镜显示HNTs长度为500~1500 nm,直径为50~100 nm,CEOs/HNTs纳米粒子均匀地分散在PBAT薄膜中。与PBAT薄膜相比,CEOs/HNTs/PBAT复合薄膜的力学性能得到提高,透光和透水等物理性能在一定程度上得到改善。对金黄色葡萄球菌和大肠杆菌的抗菌效果可以达到93%和97%。同时在对草莓的保鲜试验中,取得了很好的保鲜效果。

EVA/MPE/DK-HNTs复合材料的制备及其性能

以9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)、硅烷偶联剂KH570为原料合成了DOPOKH570,并接枝于埃洛石纳米管表面,制备了端基含DOPO的埃洛石纳米管(DK-HNTs)。通过傅里叶变换红外光谱和X射线光电子能谱表征了DK-HNTs的化学组成及结构。采用熔融共混法制备了乙烯-乙酸乙烯酯共聚物/茂金属聚乙烯/DK-HNTs复合材料,考察了DK-HNTs用量对复合材料性能的影响。结果表明:少量DK-HNTs在复合材料中可以均匀分散;当DK-HNTs用量为5%(w)时,复合材料拉伸强度、拉伸断裂标称应变、残炭量分别为21.08 MPa,735%,4.20%(w)。此外,DK-HNTs的加入使复合材料的加工流动性略有下降。

Enhancement of thermal stability and UV resistance of halloysite nanotubes using zinc oxide functionalization via a solvent-free approach

The aim of this study was to synthesize and evaluate the thermal properties and ultraviolet(UV)resistance of zinc oxide-functionalized halloysite nanotubes(HNT–ZnO).The HNT–ZnO was synthesized using a facile solvent-free route.The properties of the HNT–ZnO nanofillers were characterized using zeta-potential measurement,X-ray diffraction(XRD),field-emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM),Fourier transform infrared spectroscopy(FTIR),and thermogravimetric analysis(TGA).The immobilization of ZnO nanoparticles onto HNT is feasible even at the lowest mass ratio of HNT/ZnO.The TGA results indicate that the thermal stability of the HNT–ZnO nanofillers is higher than that of the HNT.Furthermore,UV?Vis diffuse reflectance spectroscopy(UV-DRS)results show that the HNT–ZnO achieve a total reflectance as high as approximately 87.5%in the UV region,as compare with 66.9%for the HNT.In summary,the immobilization of ZnO onto HNT is a viable approach for increasing the thermal stability and improving the UV shielding of HNT.

Preparation of N-Doped TiO_2-Loaded Halloysite Nanotubes and Its Photocatalytic Activity under Solar-Light Irradiation

The N-doped TiO2-loaded halloysite nanotubes(N-Ti O2/HNTs) nanocomposites were prepared by using chemical vapor deposition method which was realized in autoclave. The photocatalytic activity of nanocomposites was evaluated by virtue of the decomposition of formaldehyde gas under solar-light irradiation. The XRD patterns verified that the anatase structured TiO2 was deposited on HNTs. The TEM images showed that the surface of HNTs was covered with nanosized TiO2 with a particle size of ca. 20 nm. The UV-vis spectra indicated that the N-Ti O2/HNTs presented a significant absorption band in the visible region between 400 nm and 600 nm. Under solar-light irradiation, the highest degradation rate of formaldehyde gas attained 90% after 100 min of solar-light irradiation. The combination of the photocatalytic property of TiO2 and the unique structure of halloysite would assert a promising perspective in degradation of organic pollutants.

Implementation of a Simulation Model of the Controlled Release of Molecular Species from Halloysite Nanotubes

In this work a three-dimensional, time-quantified Monte Carlo model that efficiently describes diffusion through and from nanotubes is implemented. Controlled delivery from Halloysite Nano-tubes (HNT) is modeled based on interactions between the HNT’s inner wall and the nanoparticles (NPs) and among NPs themselves. The model was validated using published experimental data. The validated model is then used to study the effect of multiples parameter like HNT diameter and length, particle charge, and ambient temperature on the release of encapsulated NPs. The results show that release profiles depend on the size distribution of the HNT batch used for the experiment, as delivery is sensitive to HNT lumen and length. A very good agreement with the experiment is observed when a weighted average release profile is compared to the experimental profile. Although the NP dynamics is temperature-dependent, the effect is minimum within the range of temperatures relevant to biomedical applications, but will be relevant for other applications at temperatures significantly different from room temperature. This model can be used to predict the best conditions for a particular delivery need.

Chemical Modification of Halloysite Nanotubes for the Preparation of Nanocomposites on Non Polar Matrix

In this study,we demonstrated the effects of chemical treatments for Halloysite nanotubes(HNTs)under acid and alkaline conditions using sulfuric acid and sodium hydroxide.XRD results indicate that alkaline treatment destroyed the crystalline structure and morphology for HNTs because the XRD spectrum shows the typical peaks for montmorillonite.For the acid treatment using H2SO4,XRD spectrum indicates an intensity reduction for the peak(001)showing a lower concentration of aluminium in the structure.Diffuse reflectance analysis shows a reduction of 40 and 15%for reflectance with H2SO4 and NaOH treatments respectively.A terephthalic acid adsorption test was realized with the HNTs,modified halloysites(HNT-H2SO4)and(HNT-NaOH)samples with a kinetic study and it was quantified with UV spectroscopy at 240 nm where results shown a lower adsorption for HNTs treated with H2SO4 in comparison with alkaline treatment and not treated HNT.A decrease of 58%±0.3was achieved with the sulfuric acid treatment with not crystalline structure modification using ICP technique to quantify the sample compositions.

Two-Dimensional Co_(2)(OH)1,4-Benzenedicarboxylate-Halloysite Nanotube Nanocomposite-Epoxy Coating with High Corrosion Resistance

Introducing inorganic nanomaterials into a polymer matrix greatly improves the anticorrosion performance of epoxy coatings(EP);however,poor compatibility between the materials can limit the improvement in properties.In this work,based on the high interface compatibility of two-dimensional(2D)Co_(2)(OH)_(2)BDC(BDC=1,4-benzenedicarboxylate)in the epoxy coating that we reported in previous work,we fabricated a 2D Co_(2)(OH)_(2)BDC-halloysite nanotube(HNT)nanocomposite have a structure consisting of alternating of nanosheets and nanotube by in situ synthesis.The nanocomposite was characterized by Fourier transform infrared spectroscopy,X-ray diffraction,and scanning electron microscopy.The mechanical and anticorrosion performance of the 2D Co_(2)(OH)_(2)BDC-HNT/EP coating was evaluated by mechanical tests and electrochemical impedance spectroscopy spectra.Compared with a conventional unreinforced epoxy coating,the 2D Co_(2)(OH)_(2)BDC-HNT/EP coating had higher mechanical strength and toughness,and the low-frequency impedance modulus of 2D Co_(2)(OH)_(2)BDC-HNT/EP coating was increased by three orders of magnitude,demonstrating the high corrosion resistance of our reinforced coating.

改性埃洛石纳米管在聚脲基防火涂料中的应用研究

为了提高聚脲基防火涂料的防火性能,探究埃洛石纳米管对聚脲基涂料防火性能的影响,通过表面改性的方法,用甲基三甲氧基硅烷改性埃洛石纳米管,并将改性埃洛石纳米管引入到聚脲膨胀型防火涂料中,采用锥形量热仪、红外光谱分析仪、导热系数仪、场发射扫描电镜、透射扫描电镜、防火性能测试装置等对其进行表征分析。研究发现:添加质量分数为5%的改性埃洛石纳米管的涂料样品的热释放峰值为95.89 kW/m^(2),相较未添加的样品降低了38.48%;总的热释放量为7.20 MJ/m^(2),相较未添加的样品降低了76.50%;总的烟释放值为4.32 m^(2),相较未添加的样品降低了40.98%;常温下导热系数为0.067 W/(m·K),相较未添加的样品降低了17.30%;燃烧后样品残留物表面更加致密,强度更高,对烟热的释放有更好的抑制作用,表现出了优异的防火性能。实验结果表明,改性埃洛石纳米管在降低复合材料导热系数和基体树脂催化成炭方面起到了双重作用,对聚脲基防火涂料防火性能的提高起到了重要作用。

负载型MoS_(2)基加氢催化剂活性相的限域构建及其加氢脱硫活性

基于对负载型NiMo加氢脱硫催化剂活性相的结构设计,以具有内径10~30 nm直通孔道的天然埃洛石纳米管(HNT)为载体,利用其“孔道空间限域效应”作为MoS_(2)活性相结构的控制基础,以硫代钼酸铵和硝酸镍为金属前驱物,采用等体积浸渍法一次浸渍工艺,通过改变金属负载量、Ni/Mo(原子比)等工艺条件制备系列双金属NiMo/HNT催化剂。通过X射线衍射(XRD)、比表面积(BET)、高分辨透射电子显微镜(HRTEM-EDS mapping)、X射线光电子能谱仪(XPS)等手段对所得催化剂的结构进行表征,以二苯并噻吩(DBT)为模型化合物对催化剂的脱硫活性进行评价。结果表明:HNT载体的使用可有效控制MoS_(2)活性相尺寸,催化剂中的Mo、Ni金属组分几乎全部集中于载体的孔道内部并呈原生的亲密接触状态,同时Ni、Mo组分具有更高的硫化程度,协同效果更好;NiMo/HNT催化剂的加氢脱硫活性和加氢选择性均显著优于使用氧化铝载体的参比催化剂,其中DBT转化率最高增幅41.6%,反应速率R最大可以提升92%,加氢选择性最大可提升60%。

杂化纳米HNTs-d-RGO/聚乳酸复合材料的制备及热性能

以埃洛石纳米管(HNTs)和氧化石墨烯(GO)为增强填料,聚乳酸(PLA)为基体,利用硅烷偶联剂KH550(APTES)将HNTs与GO杂化获得HNTs-d-RGO纳米粒子,再通过熔融挤出热拉-骤冷工艺制备了一系列纳米HNTs-d-RGO/PLA复合材料。分别采用透射电镜、红外光谱、扫描电镜、X射线衍射、差示扫描量热分析和维卡软化仪研究了纳米HNTs-d-RGO/PLA复合材料的微观形态、结晶性能与热性能。结果表明,与GO的结晶衍射峰相比,杂化HNTs-d-RGO相应的特征衍射峰强度明显减弱;与纯PLA相比,当HNTs-d-RGO含量达到5%时,其结晶度和耐热变形温度较纯PLA分别提高了19.3%和54.3℃,当HNTs-d-RGO含量达到7%后,纳米HNTs-d-RGO/PLA复合材料团聚现象明显,而相应的结晶度和耐热变形温度出现了一定程度的下降。

埃洛石纳米管对铜胁迫下小麦幼苗生长的影响

在水培条件下设置3个铜(Cu)处理[20 mg/L Cu^(2+)(20Cu)、50 mg/L Cu^(2+)(50Cu)和100 mg/L Cu^(2+)(100Cu)],研究外源添加50 mg/L埃洛石纳米管(HNTs)对Cu胁迫下小麦幼苗生长、气孔大小、叶绿体色素含量、根系氧化损伤、植株内Cu^(2+)含量的影响,以期为HNTs缓解重金属污染对作物生长的影响提供理论依据。结果表明,外源添加HNTs显著提高了Cu胁迫下小麦幼苗的株高、根长,20Cu+HNTs、50Cu+HNTs、100Cu+HNTs处理株高分别提高了13.10%、26.45%、28.30%,根长分别提高了62.87%、56.68%、92.34%;外源添加HNTs显著提高了Cu胁迫下小麦幼苗干、鲜质量,叶绿素、类胡萝卜素含量,根系活力,降低了根系氧化损伤程度,其中,叶绿素a含量分别提高了34.34%、18.09%、54.76%,叶绿素b含量分别提高了44.83%、25.93%、43.75%,根系活力分别提高了38.16%、339.48%、453.56%;与100Cu处理相比,100Cu+HNTs处理小麦幼苗根系、叶片中Cu^(2+)含量分别降低了19.18%、37.02%。综上,外源添加HNTs能够降低小麦幼苗中Cu^(2+)含量,缓解重金属Cu对小麦幼苗的毒性,促进其生长。

埃洛石纳米管在抗菌领域的应用进展

埃洛石纳米管(HNTs)是天然黏土矿物纳米材料,被广泛应用于生物医学领域。不加修饰的HNTs并不具有抗菌功效,而将HNTs经过一定修饰后可发挥显著的抗菌作用。目前研究主要集中于HNTs作为载体装载抗菌化合物产生的药物缓释作用、HNTs装载抗菌纳米颗粒对其分散性的改善、HNTs装载不同抗菌物质产生协同抗菌作用以及抗菌修饰的HNTs掺入聚合物基质对聚合物物化性能提升等方面。未来深入探究HNTs抗菌作用的原理,并降低HNTs应用于临床治疗的成本,可促进HNTs在抗菌领域的广泛应用。

水热纳米浇筑HNTs模板法制备碳纳米棒（英文）

以埃洛石纳米管(HNTs)为模板和聚乙烯醇(PVA)为碳源,采用水热纳米浇筑法成功制备出碳纳米棒。方法涉及3步,即在HNTs中浇筑PVA,碳化和模板移除。采用一系列表征手段如XRD、FT-IR、SEM、TEM、Raman、XPS、SAED和N2吸附-脱附等表征碳纳米棒的形成和结构。具有一维棒状结构的碳纳米棒具有高的比表面积(408 m^2·g^(-1))和典型的介孔特征。

g-C_3N_4/HNTs复合光催化剂的制备及其降解盐酸四环素研究

采用化学吸附法制备了类石墨相氮化碳负载埃洛石纳米管(g-C_3N_4/HNTs)的复合型光催化材料。利用扫描电镜、X射线衍射、Fourier变换红外光谱、紫外-可见漫反射光谱表征技术对合成材料的形貌和结构进行研究,利用可见光照射对降解盐酸四环素(TC)的光催化活性进一步考察。研究结果表明,HNTs负载于g-C_3N_4表面,二者表现出协同催化作用。当HNTs的质量含量为20%时,g-C_3N_4/HNTs复合材料在降解盐酸四环素溶液过程中催化活性最强。经过120min可见光照射,TC的降解率高达96.31%,证明该复合材料具有优良的光催化活性。

埃洛石纳米硅铝管(HNTs)的结构和物理性能

运用SAXS、XRD、TEM、BET、TGA、FT-IR和NH3-TPD表征手段深入研究了中国产的埃洛石纳米硅铝管（HNTs）的结构和物理性能。分别考察了焙烧温度和酸碱水热处理对HNTs纳米管结构的影响,研究了HNTs纳米管材料的质量损失和酸性位性质。结果表明,采用小角度散射表征（SAXS）计算的HNTs纳米管的孔径与TEM表征基本一致,孔径约为20~30nm;HNTs具有良好的热稳定性和较好的耐酸碱性;在400~550℃温度范围内,HNTs失去羟基缩合产生的化学水;HNTs既具有中强酸性位又具有强酸性位。

非对称双螺杆制备ABS/PUR-T/HNTs阻燃复合材料的性能

分别采用自主研制的新型同向非对称双螺杆挤出机以及传统双螺杆挤出机制备了丙烯腈–丁二烯–苯乙烯塑料(ABS)/膨胀型阻燃剂(IFR),ABS/热塑性聚氨酯弹性体(PUR-T)/IFR以及ABS/PUR-T/IFR/埃洛石纳米管(HNTs)等3种阻燃复合材料试样,表征了试样的冲击、拉伸和弯曲强度以及极限氧指数(LOI),同时测试了非对称双螺杆挤出机制备的试样的燃烧性能,分析了PUR-T和HNTs对试样性能的影响。结果表明,相比于传统双螺杆挤出机,自制非对称双螺杆挤出机由于具有更优异的混合性能,所制备的复合材料试样力学性能和LOI均有提高;针对非对称双螺杆制备的试样,加入质量分数为17.5%的PUR-T后,其冲击强度提高,而拉伸和弯曲强度降低,LOI由27%提升至40%,热释放速率峰值(PHRR)、平均热释放速率(MHRR)、总热释放量(THR)和生烟速率(SPR)降低,火灾性能指数(FPI)提高,阻燃效果显著增加;进一步加入2%的HNTs后,试样的冲击、拉伸和弯曲强度得到提高,LOI稍有下降,但仍为37%,MHRR和THR有所增大,但PHRR和SPR进一步降低,且FPI提高,有助于降低火灾危险性。