scholarly journals The Research of Crystalline Morphology and Breakdown Characteristics of Polymer/Micro-Nano-Composites

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1432 ◽  
Author(s):  
Yujia Cheng ◽  
Guang Yu ◽  
Xiaohong Zhang ◽  
Boyang Yu
Keyword(s):  
Performance Test ◽  
Breakdown Strength ◽  
Cell Structure ◽  
Crystallization Rate ◽  
Experimental Result ◽  
Inorganic Filler ◽  
Nano Zno ◽  
Shape Coefficient ◽  
Blending Method ◽  
Zno Particles

In this article, low-density polyethylene (LDPE) was used as a matrix polymer, the Micro-ZnO and Nano-ZnO particles were used as the inorganic filler. With the melt blending method, the Nano-ZnO/LDPE(Nano-ZnO particles doping into LDPE), Micro-ZnO/LDPE(Micro-ZnO particles doping into LDPE) and Micro-Nano-ZnO/LDPE (Nano-ZnO and Micro-ZnO particles doping into LDPE in the same time) composites were prepared. Then, the inorganic filler and the composites were dealt with structural characterizations and analysis by Fourier transform infrared (FTIR), Polarization microscope (PLM), and Differential scanning calorimeter (DSC). Besides, these samples were dealt with (alternating current) AC breakdown performance test. The micro-experimental results showed that the Micro-ZnO and Nano-ZnO particles doping reduced the crystal size and increased the crystallization rate. With the change of cell structure, the crystallinity of composites increased. The crystallinity order of different samples was as follows: LDPE < Micro-ZnO/LDPE < Nano-ZnO/LDPE < Micro-Nano-ZnO/LDPE. From the breakdown of the experimental result, with the same mass fraction of the different inorganic doping of particles, the breakdown strength of these composites was different. The Nano-ZnO particle doping could improve the breakdown strength of composites effectively. Among them, the breakdown strength of Nano-ZnO/LDPE and Micro-Nano-ZnO/LDPE were 11% higher and 1.3% lower than that of pure LDPE, respectively. Meanwhile, the breakdown strength of Micro-composite was the lowest but its Weibull shape coefficient was the highest. Therefore, the Micro-ZnO doping was helpful for the Nano-ZnO dispersing in the matrix, which produced the Micro-Nano-synergy effects better.

scholarly journals The Dielectric Properties Improvement of Cable Insulation Layer by Different Morphology Nanoparticles Doping into LDPE

Coatings ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 204 ◽  
Author(s):  
Guang Yu ◽  
Yujia Cheng ◽  
Xiaohong Zhang
Keyword(s):  
Dielectric Properties ◽  
Space Charge ◽  
Crystallization Rate ◽  
Crystal Habit ◽  
Breakdown Field ◽  
Interface Traps ◽  
Insulation Layer ◽  
Nano Zno ◽  
Cable Insulation ◽  
Zno Particles

Low density polyethylene (LDPE) doped with inorganic nano-MMT and nano-ZnO particles improved the dielectric properties of the cable insulation layer. In this article, nano-MMT/LDPE and nano-ZnO/LDPE composites were prepared by polymer intercalation and melt blending, respectively. The octadecyl quaternary ammonium salt and silane coupling agent were applied for surface modification in nano-MMT and nano-ZnO particles, and this then improved the compatibility of nanoparticles and polymeric matrix. These samples were characterized by FTIR, PLM, DSC and TSC, from which the effect of nanoparticles doping on polymer crystal habit and interface traps would be explored. In these experiments, the AC breakdown characteristics and space charge characteristic of different composites were studied. The experimental results showed that the interface bonding of nanoparticles and polymer was improved by coupling agents modifying. The dispersion of nanoparticles in matrix was better. When the mass fraction of nanoparticles doping was 3 wt.%, the crystallization rate and crystallinity of composites increased, and the crystalline structure was more complete. Besides, the amorphous regions in material decreased and the conducting channel was circuitous. At this time, the breakdown field strength of nano-MMT/LDPE and nano-ZnO/LDPE increased by 10.3% and 11.1%, compared to that of pure LDPE, respectively. Furthermore, the density and depth of interface traps in polymer increased with nanoparticles doping. Nano-MMT and nano-ZnO could both restrain the space charge accumulation, and the inhibiting effect of nano-ZnO was more visible.

scholarly journals Effect of Particles Size on Dielectric Properties of Nano-ZnO/LDPE Composites

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 5 ◽  
Author(s):  
YuJia Cheng ◽  
Liyang Bai ◽  
Guang Yu ◽  
Xiaohong Zhang
Keyword(s):  
Field Strength ◽  
Crystal Habit ◽  
Experimental Result ◽  
Breakdown Field ◽  
Specimen Thickness ◽  
Scanning Calorimetry ◽  
Nano Zno ◽  
Zno Particles ◽  
Ldpe Composites ◽  
Breakdown Field Strength

The melt blending was used to prepare 3 wt% ZnO/low density polyethylene (ZnO/LDPE) nanocomposites in this article. The effect of different inorganic ZnO particles doping on the dielectrical property and crystal habit of LDPE matrix was explored. The nanoparticles size was 9 nm, 30 nm, 100 nm, and 200 nm respectively. Scanning electron microscope (SEM) was used to characterize ZnO nanoparticles whereas differential scanning calorimetry (DSC) was used to make thermal characterization of the samples. Besides, the AC (alternating current), DC (direct current breakdown characteristics and electrical conductivity of the nanocomposites was studied in this article. The experimental results showed that nano-ZnO/LDPE composites had the advantages such as small crystal size, high crystallization rate and crystallinity owing to nano-ZnO particles doping, when doping nano-ZnO particles size was 30 nm, the ZnO/LDPE nanocomposite crystallinity crest value 39.77% appeared. At the mean time, the DC and AC breakdown field strength values of composites were 138.0 kV/mm and 340.4 kV/mm respectively. They were the maximal values which improved 8.24% and 13.85% than LDPE. The AC breakdown field strength of samples decreased with specimen thickness increase. The DC breakdown field strength of LDPE and ZnO/LDPE composites were greater than AC breakdown field strength. From the conductivity experimental result it could be seen that when the experimental temperature and electric field intensity rose, the current density and conductivity of ZnO/LDPE composites increased with the enlargement of ZnO particles size. But the values were less than which of LDPE.

scholarly journals Effect of Different Size ZnO Particle Doping on Dielectric Properties of Polyethylene Composites

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Yujia Cheng ◽  
Guang Yu ◽  
Zhuohua Duan
Keyword(s):  
Particle Size ◽  
Field Strength ◽  
Experimental Results ◽  
Dominant Factor ◽  
Breakdown Field ◽  
Inorganic Filler ◽  
Nano Zno ◽  
Zno Particles ◽  
The Matrix ◽  
Breakdown Field Strength

In this article, low density polyethylene was used as a matrix polymer. The ZnO particles with diameters of 30 nm and 1 μm were used as inorganic filler. The nano-ZnO particles after surface modification would disperse in the matrix uniformly. The nano-, micro-, and micro-/nano-ZnO/LDPE were prepared by melt blending. During the experiment, the microstructures of different composites were characterized and discussed by SEM and DSC. Besides, the micro- and nano-ZnO/LDPE underwent a breakdown test, conductance test, and dielectric spectrum test. The microscopic experimental results showed that the ZnO particles dispersed uniformly in the LDPE matrix. The crystallinity of composites was higher than that of pure LDPE. Among them, the maximum crystallinity was 39.77% when the nano-ZnO particle size was 30 nm. It was 16.1% higher than pure LDPE. The macroscopic experimental results showed that the effect of micro- and nano-ZnO particle doping on breakdown properties of polymers was different. Among them, the breakdown field strength of nano-ZnO/LDPE was the highest at 138.0 kV/mm, which was 8.24% higher than that of pure LDPE. The micro-/nano-ZnO/LDPE took second place, which was still higher than pure LDPE. As the thickness of samples increased, the thermal breakdown was the dominant factor in the breakdown test. The AC breakdown field strength of all composites tended to decrease, and the reduction of micro-ZnO/LDPE was lower than that of nano-ZnO/LDPE. Besides, the dispersion of the breakdown became better. Moreover, the micro- and nano-ZnO particle doping could improve the conductivity characteristic of polymer effectively. The dielectric constant and dielectric loss of composites increased with the increase of the particle size.

Comparative Characterization of Different Samples Containing Nano-ZnO Particles with Applicability in Topical Therapies

2019 ◽  
Vol 56 (3) ◽  
pp. 652-656
Author(s):  
Raul Chioibas ◽  
Florin Borcan ◽  
Ovidiu Mederle ◽  
Dana Stoian ◽  
Codruta Marinela Soica
Keyword(s):  
Synthesis Method ◽  
Pharmaceutical Preparations ◽  
Ultrasound Treatment ◽  
Heating Process ◽  
White Pigment ◽  
Nano Zno ◽  
Zno Particles ◽  
Repeated Freezing ◽  
Skin Healing

Zinc oxide (ZnO) is an inorganic compound used for its antiseptic and skin healing properties. It is an excellent protective filter against UV radiation and it can be used as white pigment in pharmaceutical preparations. In this study, nano-ZnO particles were obtained by ultrasound treatment, and respectively by repeated freezing/heating process. The influence of synthesis method and of ultrasound generator parameters on the particles size and stability was observed. The results reveal that were obtained samples with a very good stability and sizes between 15 and 96 nm. It was found that synthesis based on ultrasound treatment lead to the formation of nanoparticles with lower sizes.

Preparation and Co (II) Removal of ZnO/Poly-Piperazineamide Nanofiltration Membranes

2017 ◽  
Author(s):  
Xiaoguang Zhang ◽  
Xuexing Chen ◽  
Qingchun Chen ◽  
Zhaolong Deng ◽  
Yan Liu ◽  
...  
Keyword(s):  
Reaction Time ◽  
Monomer Concentration ◽  
Attenuated Total Reflection ◽  
Radioactive Nuclide ◽  
Separation Performance ◽  
Separation Mechanism ◽  
Nanofiltration Membranes ◽  
Terephthaloyl Chloride ◽  
Nano Zno ◽  
Zno Particles

A series of nanofiltration membranes were prepared by interfacial polymerization of piperazine and terephthaloyl chloride on the surface of polyacrylonitrile (PAN) ultrafiltration membranes. ZnO nanoparticles were incorporated in the active separation layer to modify the performances of the membranes. The preparation conditions as the monomer concentration, dosage of nano-ZnO particles and the reaction time on removal of a simulated radioactive nuclide Co (II) were investigated. Fourier transform infrared in attenuated total reflection mode verified the formation of polyamide on the PAN ultrafiltration membrane. The scanning electron microscope images showed that the nano-ZnO particles can homogeneously fixed on the membrane surface. The retention of Co (II) increased with increasing the dosage of nano-ZnO in the range of 0∼0.03 g. Further adding more nano-ZnO, the rejection rate of Co (II) first decreased and then increased. The concentration of piperazine and terephthaloyl chloride showed similar effect on removal of Co (II) ion. 5 minutes polymerization time was sufficient to form an active separation layer on the substrate membrane which changed the separation mechanism from ultrafiltration to nanofiltration. The separation performance of NF3 prepared by the following conditions was optimum: 0.03g nano-ZnO, 0.6 wt% piperazine, 0.5 wt% terephthaloyl chloride, and the reaction time was 15 min. The rejection rates of 1000 mg/L Na2SO4 and Co2+ in CoCl2 solution were 90% and 75% respectively. The Co (II) removal rate can be increased to nearly 90% by using ethylenediaminetetraacetic acid disodium salt. Increasing the operation pressure or the feeding concentration of Co (II) can also improve the performances of the membranes in this experiment.

scholarly journals Effects of zinc acetate and cucurbit[6]uril on PP composites: crystallization behavior, foaming performance and mechanical properties

e-Polymers ◽  
2018 ◽  
Vol 18 (6) ◽  
pp. 491-499 ◽  
Author(s):  
Yuhui Zhou ◽  
Li He ◽  
Wei Gong
Keyword(s):  
Impact Strength ◽  
Flexural Strength ◽  
Zinc Acetate ◽  
Crystallization Behavior ◽  
Cell Structure ◽  
Weight Ratio ◽  
Crystallization Rate ◽  
Sem Images ◽  
Improvement Effect ◽  
Lower Temperature

AbstractIn this study, polypropylene (PP) foams were prepared with 1.0 wt% of cucurbit[6]uril (Q[6]), zinc acetate (Zn(Ac)2), Zn@Q[6] (a supramolecular compound synthesized from Q[6] and Zn(Ac)2), or a mixture of Zn(Ac)2 and Q[6] (weight ratio of 1:1) through injection molding in the presence of a chemical blowing agent, azodicarbonamide. The effect of the additions on the crystallization behavior and foaming performance of PP and the mechanical characterizations of the foaming samples were determined. The results showed that the additions can change the crystallization type from homogeneous to heterogeneous, increase the crystallization rate and shrink the size but increase the density of spherulites. Among the additions, Q[6] most significantly altered the crystallization properties. Scanning electron microscopy (SEM) images revealed that the PP foaming performance can be improved by Zn(Ac)2 addition at a lower temperature (175°C); however, further increasing the temperature had an undesirable effect. Q[6] exhibited the optimum foaming improvement effect on PP in a wide temperature range (175–195°C). Adding nanoparticles also enhanced the tensile properties, flexural strength and impact strength of foaming PP at low temperatures. However, with increasing temperature, the poor cell structure demonstrated undesirable effects in terms of tensile strength, flexural strength and impact strength.

Sign in / Sign up

Export Citation Format

Share Document