Effect of imidization process on the performance of PI/nano-Al2O3 three layer composite film

2017 ◽  
Vol 46 (4) ◽  
pp. 327-331 ◽  
Author(s):  
Lizhu Liu ◽  
Hongju He ◽  
Ling Weng ◽  
Xiaorui Zhang
Keyword(s):  
Composite Film ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Composite Films ◽  
Inorganic Materials ◽  
Raw Material ◽  
Nanocomposite Films ◽  
Breakdown Field ◽  
Content Type ◽  
The Impact

Purpose The purpose of this paper was to comprehensively understand the effects of imidization process on the structure and properties of polyimide (PI) films through the preparation and characterization of a variety of PI/aluminium oxide (Al2O3) nanocomposite films by using several imidization-based strategies. Design/methodology/approach Poly(amic acid) (PAA) containing different amounts of inorganic materials (namely, 0 Wt.%, 4 Wt.%, 8 Wt.%, 12 Wt.% and 16 Wt.%) was synthesized by using pyromellitic dianhydride and 4,4-diaminodiphenyl ether as raw material and N,N-dimethylacetamide as solvent. Subsequently, the solution obtained was casted on a glass substrate and dried by the means of various curing processes. The micro-structure, Fourier transform–infrared spectral features, breakdown field strength, dielectric properties and the corona-resistant time parameters of films were achieved. Findings The imidization process influences substantially the properties of composite films. Therefore, as the imidization rate is increased, the corona-resistant time and the electrical breakdown strength of composite films are also improved, while the dielectric constant faces a+ decreasing. Research limitations/implications In this paper, the impact of imidization process on the performance of PI/nano-Al2O3 three-layered composite film is reported. However, there are multiple factors governing these systems (such as, interlayer thickness ratio and humidity), which are not discussed herein. Originality/value The current study expounds the relationship between imidization ratios as well as the effect of imidization ratio on the performance of the film.

Effects of interface bonding on the corona resistance of the polyimide/nano-Al2O3 three-layer composite films

2017 ◽  
Vol 30 (10) ◽  
pp. 1240-1246 ◽  
Author(s):  
Xinyu Ma ◽  
Lizhu Liu ◽  
Hongju He ◽  
Ling Weng
Keyword(s):  
Composite Film ◽  
Breakdown Strength ◽  
In Situ Polymerization ◽  
Electrical Breakdown ◽  
Layer Structure ◽  
Composite Films ◽  
Raw Material ◽  
Breakdown Field ◽  
Layer Composite ◽  
Corona Resistance

Polyimides (PIs) are widely used in many fields including aerospace and microelectronics. Due to their poor corona resistance, their practical applications were limited, especially in the field of variable frequency motors. In this study, we have achieved for the first time to increase the corona resistance by controlling the preparation process of the three-layered PI composite. A series of PI/nano-Al2O3 composite films with novel three-layer structure were prepared by in situ polymerization employing pyromellitic dianhydride and 4,4-diaminodiphenyl as raw material, N, N-dimethylacetamide as solvent, and doping of nano-Al2O3. The first layer of the PI/Al2O3 composite film was characterized by Fourier transform infrared spectroscopy, and the imidization rate under different processes was calculated. The interface structures and bonding conditions of the composite films were characterized by scanning electron microscope, and the surface morphologies of the composite films treated by different corona-resistance times were investigated. X-ray diffraction analysis was also used to study the effect of nano-Al2O3 on PIs with different imidization ratios. The corona-resistance time and breakdown field strength of the composite films prepared by different processes were also tested. The results indicated that the combination of the three-layer composite film and the corona-resistance abilities of the composite membrane surface was enhanced by increasing the imidization rate. Meanwhile, the corona-resistance time and the electrical breakdown strength of composite films were also improved by increasing the imidization rate.

The Effects of Coupling Agents on the Electrical Properties of Polyimide/TiO2 Hybrid Films

2014 ◽  
Vol 556-562 ◽  
pp. 371-374
Author(s):  
Kai Yan ◽  
Xiao Xu Liu
Keyword(s):  
Composite Film ◽  
Breakdown Strength ◽  
In Situ Polymerization ◽  
Composite Films ◽  
Electric Breakdown ◽  
Future Application ◽  
Breakdown Field ◽  
Coupling Agents ◽  
Hybrid Films ◽  
Simple Method

Polyamides (PI)-matrix composite films with inorganic nanoTiO2 have been fabricated by employing in situ polymerization. Before addition, TiO2 particles were firstly modified with coupling agents (KH550). The electric breakdown strength and micromorphology of hybrid films were characterized and investigated. Results indicated that nanoTiO2 particles were homogeneously dispersed in the PI matrix for the addition of coupling agents and the electric breakdown strength of PI/TiO2 composite films with KH550 were better than unmodified PI composite film. The breakdown field strength and tensile modulus of PI composite film with the inorganic content of 5 wt% were 200.1 (KV/mm). So the using coupling agent can effectively improve the compatibility and the homogenous dispersion of nanoTiO2 particles in PI matrix. Meanwhile, the procedure described here offers an effective and simple method to produce PI/TiO2 with excellent electrical needed for future application in electrical engineering field.

Fabrication, Morphology and Properties of Polyimide/Al2O3 Nanocomposite Films via Surface Modification and Ion-Exchange Technique

2018 ◽  
Vol 921 ◽  
pp. 91-98
Author(s):  
Ming Yu Zhang ◽  
Li Zhu Liu ◽  
K.S. Hui
Keyword(s):  
Ion Exchange ◽  
Composite Film ◽  
Original Film ◽  
Treatment Time ◽  
Breakdown Strength ◽  
Composite Films ◽  
Nanocomposite Films ◽  
Polyimide Films ◽  
Force Microscopy ◽  
Corona Resistance

Polyimide films with Al2O3composite layers were prepared by KOH solution surface hydrolysis, ion exchange and heat treatment. Scanning electron microscope (SEM), atomic force microscopy (AFM), X-ray diffractometry (XRD), thermo gravimetric analyzer (TGA), breakdown voltage tester, high frequency pulse voltage machine were performed to characterize the micromorphology, thermal stability, mechanical properties, electric breakdown strength, and corona resistance time of composite films. Results indicated that the thermal properties of the composite film are better than the original film. The corona resistance time of the composite film was longer than that of the pristine film. The composite film had the longest corona resistance time and reached 101.2min while the KOH treatment time was 90min.

Preparation and Dielectric Property of Al2O3 Surface Coating Modified BaTiO3/Polyimide Composite Film

2014 ◽  
Vol 908 ◽  
pp. 63-66
Author(s):  
Ya Jun Wang ◽  
Xiao Juan Wu ◽  
Chang Gen Feng
Keyword(s):  
Dielectric Constant ◽  
Barium Titanate ◽  
Composite Film ◽  
Breakdown Strength ◽  
In Situ Polymerization ◽  
Chemical Properties ◽  
Dielectric Strength ◽  
Xrd Analysis ◽  
Nanocomposite Films ◽  
The Matrix

Polyimide (PI) was chosen as the matrix of the composite, barium titanate/polyimide (BT/PI) nanocomposite films were prepared by in situ polymerization. In order to improve the dispersion and the physical-chemical properties of BT surface, barium titanate was modified by Al2O3coating and modified BT/PI nanocomposite films were prepared. The prepared modified BT was characterized by X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM), and the dielectric properties of the composites were characterized in detail. It was shown that surface modification with Al2O3is the chemical process and there were new substances forming. When BT was modified by 10 wt% Al2O3, the dielectric constant of the composite film was 18.96 (103Hz), the loss tangent 0.005, breakdown strength 70 MV·m-1, energy storage density 0.41 J·cm-3. The dielectric constant of BT modified by Al2O3is decreased while the dielectric strength of the modified BT/PI composite film is increased.

Eco product development combining eco design and life cycle assessment

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ana Jamile Damasceno Barbosa ◽  
Vitor Hugo de Paiva Santos ◽  
Priscilla Cavalcante de Araújo ◽  
Felipe Lucas de Medeiros ◽  
Letícia Yasmin da Silva Otaviano
Keyword(s):  
Life Cycle ◽  
Comparative Analysis ◽  
Environmental Impact ◽  
Product Life Cycle ◽  
Raw Material ◽  
Real Problem ◽  
Cotton Swab ◽  
Content Type ◽  
Original Product ◽  
The Impact

PurposeThe paper aims to propose the development of an eco product to replace the traditional cotton swab that meets the expected needs, besides having a bias based on sustainability and economic viability.Design/methodology/approachThe applied nature article opted for an exploratory and descriptive study, with the objective of seeking a solution to a real problem: to reduce the environmental impact in the disposal of cotton swabs. To test this hypothesis, the exploratory stage evaluated the literature on the principles of eco design and environmental marketing to understand market viability and environmental impacts. The descriptive phase presented a comparative analysis between the original product and the proposed one, in terms of production processes and impacts of the product life cycle. Thus, an alternative product was conceived and validated applying the life cycle analysis (LCA).FindingsThe paper provides a comparative analysis between the eco product and the traditional product in order to validate the hypothesis that the new proposal reduces the environmental impact. It was found that both productive processes have similar impacts; however, the raw material of the proposed eco product demonstrated a significant reduction in the impact caused on the environment, considering cradle to cradle analysis.Originality/valueThis paper conceives an eco product as an alternative to traditional cotton swab, presenting an innovative potential in line with worldwide sustainability trends.

Fabrication and characterization of polyimide/Al2O3 composite films via surface modification and ion exchange technique

2016 ◽  
Vol 45 (1) ◽  
pp. 30-37 ◽  
Author(s):  
M.Y. Zhang ◽  
L.Z. Liu ◽  
L. Weng ◽  
W.W. Cui ◽  
K.S. Hui
Keyword(s):  
Surface Modification ◽  
Ion Exchange ◽  
Breakdown Strength ◽  
Composite Films ◽  
Annealing Treatment ◽  
Ambient Air ◽  
Ammonia Solution ◽  
Excellent Thermal Stability ◽  
Content Type ◽  
General Importance

Purpose – The aim of this study was to fabricate polyimide (PI)/Al2O3 composite films via surface modification and ion exchange techniques, and examine their properties. Design/methodology/approach – The method involves hydrolyzing the PI film double surface layers in an aqueous potassium hydroxide (KOH) solution and incorporating aluminium ions (Al3+) into the hydrolyzed layers of the PI film via subsequent ion exchange, followed by a treatment of the Al3+-loaded PI films with an aqueous ammonia solution, which leads to the formation of Al(OH)3 in the surface-modified layers. After a final thermal annealing treatment in ambient air, the Al(OH)3 decomposes to Al2O3, and forms composite layers on both surfaces of the re-imidized PI film. Findings – The PI/Al2O3 composite film obtained with a 6 hours of KOH treatment exhibited excellent thermal stability, good mechanical properties and better electric breakdown strength and corona-resistance properties than the pristine PI film. Practical implications – The method for obtaining the composite films in this paper is worth consideration, but additional research will be needed. Furthermore, this method is of general importance for the fabrication of composite PI films with tailored properties. Originality/value – This study showed that surface modification and ion-exchange techniques are powerful methodologies for the fabrication of PI/Al2O3 composite films.

An investigation on the impact of industrial symbiosis implementation on organizational performance using analytical hierarchical approach

2019 ◽  
Vol 27 (2) ◽  
pp. 886-911 ◽  
Author(s):  
Vimal K.E.K. ◽  
Jayakrishna K. ◽  
Thaha Ameen ◽  
Syed Shoaib Afridhi ◽  
Varadharajan Vasudevan ◽  
...  
Keyword(s):  
Organizational Performance ◽  
Conceptual Model ◽  
Raw Material ◽  
Relationship Matrix ◽  
Industrial Symbiosis ◽  
Priority Score ◽  
Content Type ◽  
Global Priority ◽  
The Impact ◽  
The Relationship

Purpose Industrial symbiosis (IS) is basically a synergistic association between two or more industries or businesses wherein the waste or by-product of one industry becomes the raw material or immediate material of another industry. IS is believed to bring in significant benefits to the organizations. Thus, the purpose of this paper is to evaluate the competitiveness attained through IS. Design/methodology/approach Analytic hierarchy process was adopted to analyze the various organizational competitiveness of IS implementation. The conceptual model was developed to understand the interrelationship between 14 outcomes and 5 organizational competitiveness which are identified from the literature review. The attainment of these five organizational competitiveness was evaluated by computing the global priority score of the outcomes. Findings The global priority score suggests that the organizational collaboration (0.19) is the important output. Further, collective learning and growth (44 percent) have been identified as the important competitiveness attained through the implementation of IS. Practical implications The relationship matrix developed can be used by the practicing managers/researchers to understand the various interactions. Thus, systematic decision making and guidance for future implementation studies will be ensured. Originality/value In the past, few authors discussed the conceptualization of IS; however, the impact of IS on the organizational performance was not extensively studied. Therefore, a conceptual model was proposed to analyze the attainment of various competitiveness through the participation of industrial symbiosis network. Further, based on the computed scores, the relationship matrix developed between outcomes and organizational competitiveness is one of the significant contributions of this work.

Characteristics of Nanocomposite ZrO2/Al2O3 Films Deposited by Plasma-Enhanced Atomic Layer Deposition

2007 ◽  
Vol 7 (11) ◽  
pp. 4180-4184
Author(s):  
Sun Jin Yun ◽  
Jung Wook Lim ◽  
Hyun-Tak Kim
Keyword(s):  
Atomic Layer Deposition ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Composite Films ◽  
Atomic Layer ◽  
Nano Composite ◽  
Layer Deposition ◽  
Electrical Breakdown Strength ◽  
Film Characteristics ◽  
Al2o3 Films

Nanocomposite ZrO2/Al2O3 (ZAO) films were deposited on Si by plasma-enhanced atomic layer deposition and the film characteristics including interfacial oxide formation, dielectric constant (k), and electrical breakdown strength were investigated without post-annealing process. In both the mixed and nano-laminated ZAO films, the thickness of the interfacial oxide layer (TIL) was considerably reduced compared to ZrO2 and Al2O3 films. The TIL was 0.8 nm in nano-composite films prepared at a mixing ratio (ZrO2:Al2O3) of 1:1. The breakdown strength and the leakage current level were greatly improved by adding Al2O3 as little as 7.9% compared to that of ZrO2 and were enhanced more with increasing content of Al2O3. The k of ZrO2 and mixed ZAO (Al2O3 7.9%) films were 20.0 and 16.5, respectively. These results indicate that the addition of Al2O3 to ZrO2 greatly improves the electrical properties with less cost of k compared to the addition of SiO2.

scholarly journals Carrier Transport and Molecular Displacement Modulated dc Electrical Breakdown of Polypropylene Nanocomposites

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1207 ◽  
Author(s):  
Daomin Min ◽  
Chenyu Yan ◽  
Rui Mi ◽  
Chao Ma ◽  
Yin Huang ◽  
...  
Keyword(s):  
Energy Storage ◽  
Charge Transport ◽  
Carrier Mobility ◽  
Breakdown Strength ◽  
Electrical Breakdown ◽  
Dielectric Materials ◽  
Breakdown Field ◽  
Smart Power ◽  
Electrical Breakdown Strength ◽  
Effective Carrier

Dielectric energy storage capacitors have advantages such as ultra-high power density, extremely fast charge and discharge speed, long service lifespan and are significant for pulsed power system, smart power grid, and power electronics. Polypropylene (PP) is one of the most widely used dielectric materials for dielectric energy storage capacitors. It is of interest to investigate how to improve its electrical breakdown strength by nanodoping and the influencing mechanism of nanodoping on the electrical breakdown properties of polymer nanocomposites. PP/Al2O3 nanocomposite dielectric materials with various weight fraction of nanoparticles are fabricated by melt-blending and hot-pressing methods. Thermally stimulated current, surface potential decay, and dc electrical breakdown experiments show that deep trap properties and associated molecular chain motion are changed by incorporating nanofillers into polymer matrix, resulting in the variations in conductivity and dc electrical breakdown field of nanocomposite dielectrics. Then, a charge transport and molecular displacement modulated electrical breakdown model is utilized to simulate the dc electrical breakdown behavior. It is found that isolated interfacial regions formed in nanocomposite dielectrics at relatively low loadings reduce the effective carrier mobility and strengthen the interaction between molecular chains, hindering the transport of charges and the displacement of molecular chains with occupied deep traps. Accordingly, the electrical breakdown strength is enhanced at relatively low loadings. Interfacial regions may overlap in nanocomposite dielectrics at relatively high loadings so that the effective carrier mobility decreases and the interaction between molecular chains may be weakened. Consequently, the molecular motion is accelerated by electric force, leading to the decrease in electrical breakdown strength. The experiments and simulations reveals that the influence of nanodoping on dc electrical breakdown properties may origin from the changes in the charge transport and molecular displacement characteristics caused by interfacial regions in nanocomposite dielectrics.

scholarly journals Effect of Ce Doping on RGO-TiO2Nanocomposite for High Photoelectrocatalytic Behavior

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Md. Rakibul Hasan ◽  
Chin Wei Lai ◽  
Sharifah Bee Abd Hamid ◽  
Wan Jeffrey Basirun
Keyword(s):  
Composite Film ◽  
Sol Gel ◽  
Composite Films ◽  
Visible Region ◽  
Rutile Phase ◽  
Nanocomposite Films ◽  
Tetrabutyl Titanate ◽  
Photoelectrochemical Performance ◽  
Solar Simulator ◽  
Fourier Transformed Infrared Spectroscopy

Ce doped RGO-TiO2composite films on ITO substrates were prepared by sol-gel process using tetrabutyl titanate and reduced graphene oxide (RGO) as the starting materials. The sample was designed for the photoelectrocatalytic applications. The obtained samples were characterized by X-ray diffraction, UV-vis absorption spectroscopy, scanning electron microscopy, and Fourier transformed infrared spectroscopy. The results showed that doping of Ce on RGO-TiO2composite film inhibited the TiO2anatase-rutile phase transformation. In this case, Ce atoms could serve as dispersion oxide and suppress the recombination of photoinduced electron-hole pairs. Besides, the change in absorbance from UV to visible region was observed in Ce doped RGO-TiO2nanocomposite films. The Ce doped RGO-TiO2composite film showed higher photoelectrochemical performance than that of RGO-TiO2composite and pure TiO2under solar simulator irradiation. The main reason might be attributed to the optimum content of Ce that could act as electrons acceptor to hinder the recombination loss and facilitate the better transportation for photoinduced charge carriers.

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