IET Nanodielectrics最新文献

{"title":"Patch-Based Class-Conditioned Diffusion Augmentation of TEM Images: Effects of Training Patch Size on Dispersion-Relevant Morphology in Epoxy Nanocomposites","authors":"Takahiro Umemoto,&nbsp;Takahiro Imai,&nbsp;Toshikatsu Tanaka","doi":"10.1049/nde2.70038","DOIUrl":"https://doi.org/10.1049/nde2.70038","url":null,"abstract":"<p>Transmission electron microscopy (TEM) is widely used to evaluate nanoparticle dispersion in polymer nanocomposites, which strongly influences their dielectric and insulation performance. However, the limited availability of TEM images restricts data-driven analysis. In our previous work, we established a framework to extract dispersion-related descriptors from TEM images and relate them to three-dimensional dispersion states. This study investigates the feasibility of augmenting limited TEM datasets using a patch-based, class-conditioned diffusion model and clarifies the effect of training patch size on reconstruction fidelity. Three TEM images (640 × 640 pixels) with different filler sizes and dispersion states were used. Training datasets were generated by cropping patches of various sizes (16–512 pixels), followed by rotation and flipping. A class-conditioned denoising diffusion probabilistic model with a U-Net backbone was employed to generate synthetic images. Quantitative evaluation was conducted using particle area fraction, Feret diameter distribution and Delaunay-based interparticle distance. An integrated error metric revealed a nonmonotonic dependence on patch size for all three samples, with the largest errors at the smallest patch size and an interior minimum in every case. The error varied only slowly near the minimum in each case, so that the result is better described as a range of comparable patch sizes than as a single optimum; for the samples examined here the position of this range was larger for the sample with the larger modal Feret diameter of the segmented features. These results provide an initial, empirically derived basis for selecting the patch size in diffusion-based augmentation of TEM images, subject to the limited number of source images used here.</p>","PeriodicalId":36855,"journal":{"name":"IET Nanodielectrics","volume":"9 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/nde2.70038","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149206205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flexible Interfacial Anchoring via Titanate Coupling Agent Enables Enhanced Dielectric and Electromechanical Actuation Performance in BaTiO3/TPU Nanocomposites","authors":"Zhaobei Chen,&nbsp;Huiyi Hu,&nbsp;Xin Teng,&nbsp;Congzhou Zeng,&nbsp;Xuanbing Jin,&nbsp;Lingzhi Nie,&nbsp;Zhimin Dang,&nbsp;Qixin Zhuang,&nbsp;Peiyuan Zuo","doi":"10.1049/nde2.70037","DOIUrl":"https://doi.org/10.1049/nde2.70037","url":null,"abstract":"<p>Incorporating high-permittivity ceramic nanofillers is an effective strategy to enhance the dielectric constant via interfacial polarisation, thereby boosting the electromechanical sensitivity of dielectric elastomer actuators (DEAs). However, filler agglomeration due to surface energy mismatch deteriorates material properties and weakens actuation capabilities. To address this challenge, we propose a ‘flexible interfacial anchoring’ strategy distinct from conventional rigid modification. KR38S coupling agents are covalently anchored onto BaTiO₃ nanoparticles via condensation reaction. Unlike hyperbranched modification requiring a thick polymer coating and topological interlocking, the long dioctyl chains of KR38S achieve a dual function: hydrophobic alkyl segments form an isolation layer that mitigates interfacial voids and charge traps, while flexible chains entangle with TPU polyether soft segments, creating a compliant cushion layer dynamically interconnected with the matrix. Benefiting from improved dispersibility and compatibility, the dielectric properties of the composites were substantially enhanced. The breakdown strength increased from 154.5 kV/mm for pristine TPU to 213.2 kV/mm for 5 wt% mBT/TPU, and the 10 wt% composite achieved an actuation displacement of 3.03 mm at 46.2 kV/mm, compared to 0.69 mm for pristine TPU at 29.2 kV/mm. This study provides a facile route to high-performance DEAs for soft robotics, flexible electronics, and intelligent wearables.</p>","PeriodicalId":36855,"journal":{"name":"IET Nanodielectrics","volume":"9 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2026-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/nde2.70037","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149145775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Calculation and Verification of the Thermal Time Constant of a Circular Element of a DC-Link Capacitor","authors":"Zuo Qianglin,&nbsp;Lei Qiaoshu,&nbsp;Zhang Maoshan,&nbsp;Zhang Jihong","doi":"10.1049/nde2.70034","DOIUrl":"https://doi.org/10.1049/nde2.70034","url":null,"abstract":"<p>Based on the principle of thermoelectric duality and the definition of thermal resistance and the thermal time constant (TTC) of elements, the calculation method of the TTC corresponding to different diameters of elements is derived in this paper. According to the laws of heating and cooling of elements, the measurement and calculation method of the TTC of elements is designed. The heat dissipation coefficient of the element surface to air during heating and cooling is determined by the laws of heating and cooling of the element surface. The calculation methods of the thermal resistance and the TTC of the element are obtained from the temperature rise of the platinum resistance embedded in element with different diameters during the specified time. The experimental data show that the calculation method of the TTC derived from the thermoelectric duality principle is basically correct and can be used in engineering practice. The TTC test method of a dry-type DC-link capacitor designed in this paper is correct and has good repeatability, which has value for popularisation and application. In this paper, the surface heat dissipation coefficient of the cylindrical element of a dry-type DC-link capacitor is measured and calculated by temperature rise and time. The experimental results show that the closer the position is to the centre of the element, the greater the corresponding TTC is. The TTC of cooling is 1.5 times that of heating. This is very important for improving the quality of DC-link capacitor elements and evaluating the operating temperature of capacitors.</p>","PeriodicalId":36855,"journal":{"name":"IET Nanodielectrics","volume":"9 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/nde2.70034","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149145703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermo-Oxidative Ageing of Degradable Resins Based on Different Transesterification Catalysts","authors":"Wu Fa-Yuan,&nbsp;Li Xiang-qing,&nbsp;Luo Yi-Chen,&nbsp;Chen Shuo,&nbsp;Liu He-Chen","doi":"10.1049/nde2.70035","DOIUrl":"https://doi.org/10.1049/nde2.70035","url":null,"abstract":"<p>This study investigates the influence of different transesterification catalysts on the performance evolution of degradable epoxy resins under thermal-oxidative ageing. Three resin systems were prepared using triethanolamine (TEOA), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), and zinc acetylacetonate as catalysts, followed by ageing tests at 220°C. The effects of ageing time and catalyst type on the electrical, thermal, mechanical properties and degradation behaviour of the resins were systematically analysed. Results reveal that prolonged ageing causes certain performance degradation, yet the resins still maintain favourable overall properties at the late ageing stage. The V-TEOA system shows the best performance retention after 42 days of ageing, with key indicators as follows: breakdown strength 36.7 kV/mm, dielectric loss factor 0.46%, leakage current 65.34 μA, flexural strength 67.32 MPa and temperature index 170.99°C. Meanwhile, thermal-oxidative ageing markedly weakens the degradation efficiency of the resins, and a distinct core–shell structure is found in the degraded V-TBD system. This work deepens the understanding of ageing behaviours of such resins and supports their practical application in the engineering.</p>","PeriodicalId":36855,"journal":{"name":"IET Nanodielectrics","volume":"9 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/nde2.70035","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149048455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative Performance of Uniform and Surface Functionally Graded BaTiO3-Sputtered Composite Insulators With and Without Defects","authors":"Payal Pramanik,&nbsp;Gopichand Naik M,&nbsp;Rajendra Prasad S,&nbsp;Mohamad Abed","doi":"10.1049/nde2.70036","DOIUrl":"https://doi.org/10.1049/nde2.70036","url":null,"abstract":"<p>Surface functional grading of gas-insulated switchgear (GIS) insulators using <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mtext>BaTiO</mtext>\u0000 <mn>3</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${text{BaTiO}}_{3}$</annotation>\u0000 </semantics></math> coatings has shown potential for improving electric field distribution under defect-free conditions; however, their performance on hybrid composite substrates and under realistic internal defect conditions remains insufficiently investigated. This study addresses these gaps through finite element analysis using COMSOL Multiphysics, chosen for its capability to model spatially varying dielectric properties and complex defect geometries under AC excitation. Representative GIS insulation defects; including gap voids (G-type), conductor protrusions (N-type) and free metallic particles (P-type) were modelled along with defect-free conditions. Five simultaneous performance metrics were evaluated: normalised electric field, tangential electric field, current density, leakage current and dielectric loss. Simulation results indicate that d-SFGM configurations consistently outperform d-uniform configurations across all evaluated metrics, with G-type defects yielding the largest field reductions (up to 44%–49%) and P-type defects exhibiting the highest instability. The hybrid epoxy/CF/SiC substrate demonstrated lower values across all evaluated performance metrics compared with epoxy/Al₂<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>O</mi>\u0000 <mn>3</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${mathrm{O}}_{3}$</annotation>\u0000 </semantics></math>. These findings provide simulation-based guidance for selecting coating configurations in GIS insulator design and may contribute to improving the reliability of compact urban substations.</p>","PeriodicalId":36855,"journal":{"name":"IET Nanodielectrics","volume":"9 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2026-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/nde2.70036","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149048056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interface Modification of Quantum Dots Altering Electrical Characteristics of PP-Composites for HVDC Cable Insulation","authors":"Heyu Wang,&nbsp;Zhonglei Li,&nbsp;Zechao Yang,&nbsp;Boxue Du","doi":"10.1049/nde2.70033","DOIUrl":"https://doi.org/10.1049/nde2.70033","url":null,"abstract":"<p>Polypropylene (PP) insulation for HVDC cables faces critical challenges under combined high-temperature and high-field conditions, including elevated conductivity and electric field distortion. To elucidate the role of interfacial structure engineering in governing carrier confinement mechanisms, three PP composites were developed, incorporating bare CdSe quantum dots (QDs), silane-modified CdSe@KH570 QDs and CdSe@ZnS core–shell QDs, each at 0.10 wt% loading. At 90°C, PP/CdSe@ZnS achieves a characteristic breakdown strength of 284.9 kV/mm with 44.8% enhancement and exhibits an 87.5% reduction in conductivity, significantly outperforming other modifications. Thermally stimulated depolarisation current measurements reveal that core–shell quantum dots introduce deep trap levels at 1.06 eV compared to 1.02 eV for bare CdSe composites. Interfacial potential barrier and carrier probability distribution analysis demonstrate that the inorganic ZnS shell creates high-barrier double confinement for both electrons and holes with spatial separation that minimises recombination. In contrast, the valence band energy of the organic KH570 coating closely matches that of CdSe, resulting in hole wavefunction extension into the organic layer and substantial electron–hole overlap that increases recombination probability. These findings demonstrate that interfacial engineering through inorganic core–shell architectures provides optimal carrier confinement for next-generation HVDC cable insulation operating under demanding electrothermal conditions.</p>","PeriodicalId":36855,"journal":{"name":"IET Nanodielectrics","volume":"9 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/nde2.70033","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148784367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advanced Hybridised Dielectric Elastomers With Large Actuation Strain Under Low Electric Field via Crosslinker Molecular Weight","authors":"Yu Zhao,&nbsp;Yi-Le Zhu,&nbsp;San-Ni Zhao,&nbsp;Li-Juan Yin,&nbsp;Zi-Li Zhang,&nbsp;Zhi-Min Dang","doi":"10.1049/nde2.70029","DOIUrl":"https://doi.org/10.1049/nde2.70029","url":null,"abstract":"<p>Dielectric elastomer (DE) can transfer electrical energy into mechanical energy, who demonstrates significant application potentiality in flexible actuation, sensing, and power generation. However, DE faces the technical bottleneck of high driving electric fields, limiting its practical applications. In this work, an advanced hybridised DE with silicone oil and acrylate was designed to reduce modulus and increase dielectric constant, and realize the characteristic of high driving strain under low electric field. The polysiloxane crosslinking agent with different molecular weight was prepared through the addition reaction between isocyanate and hydroxyl groups, in which dihydroxy-terminated silicone oil acted as the matrix, 4,4′-diphenylmethane diisocyanate acted as a chain extender and isocyanoethyl methacrylate acted as a capping agent. In combination with butyl acrylate (BA) to fabricate the new hybridised DE. As a result, the molecular weight of the crosslinker markedly impacts on the hybridised DE's modulus. The introduction of BA enhances the dielectric constant and reduces the modulus. The as-fabricated PM₂I-BA₁ achieves a high actuation sensitivity factor (<i>β</i>) of 34.2 and exhibits an actuation strain of 23% under an electric field of 22.5 kV/mm. The linear actuator obtains an output force of 96.3 mN (11 times its own weight) under 12.5 kV/mm.</p>","PeriodicalId":36855,"journal":{"name":"IET Nanodielectrics","volume":"9 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2026-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/nde2.70029","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148381170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Effect of Annealing on the Breakdown Strength of BOPP Dielectric Films","authors":"Xin Zhang,&nbsp;Meng Sun,&nbsp;Xueting Xia,&nbsp;Fushan Wang,&nbsp;Shouke Yan,&nbsp;Xiaoli Sun","doi":"10.1049/nde2.70027","DOIUrl":"https://doi.org/10.1049/nde2.70027","url":null,"abstract":"<p>The advancement of high-energy-density capacitors necessitates dielectric films with superior breakdown strength. Although enhancing crystallinity is a common strategy to improve dielectric breakdown performance, it is not the sole determinant of breakdown strength. This work systematically investigates the effect of annealing (60°C–140°C) on the microstructure and electrical breakdown behaviour of biaxially oriented polypropylene (BOPP) films. Annealing above 110°C is found to not only increase crystallinity and lamellar thickness but also promotes a rearrangement of the amorphous phase. A combination of in situ fourier transform infrared spectroscopy (FTIR), low-field solid-state nuclear magnetic resonance (LF-SSNMR), and Positron annihilation lifetime spectroscopy (PALS) reveals that annealing reduces free volume and significantly suppresses molecular chain mobility in the amorphous phase, as the annealing temperature raise to 140°C, the fractional free volume decreased from 0.15% to 0.09%, and the segment mobility was significantly suppressed. Consequently, the energy storage density has increased from 1.27 J/cm³ to 2.7 J/cm³, and the charge-discharge efficiency of the 140°C-annealed film still reached as high as 94.4%, meanwhile, the breakdown filed strength of the metallised 140°C-annealed film has also increased by 12.6% (≈67 MV/m). These findings demonstrate that amorphous phase mobility including mobility of functional groups, in addition to crystallinity, is a dominant factor governing breakdown behaviour. The constrained chain mobility impedes charge carrier transport and limits energy accumulation, thereby suppressing the initiation of electron avalanche breakdown. This study establishes a new structure–property relationship centred on the mobility of amorphous chains, identifying it as a key descriptor for design of high-performance dielectric polymers via annealing.</p>","PeriodicalId":36855,"journal":{"name":"IET Nanodielectrics","volume":"9 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/nde2.70027","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148166964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"","authors":"","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":36855,"journal":{"name":"IET Nanodielectrics","volume":"9 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148079739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"","authors":"","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":36855,"journal":{"name":"IET Nanodielectrics","volume":"9 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148085581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}