scholarly journals Characterizations and Significantly Enhanced Dielectric Properties of PVDF Polymer Nanocomposites by Incorporating Gold Nanoparticles Deposited on BaTiO3 Nanoparticles

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4144
Author(s):  
Kaniknun Sreejivungsa ◽  
Nutthakritta Phromviyo ◽  
Ekaphan Swatsitang ◽  
Prasit Thongbai
Keyword(s):  
Particle Size ◽  
Dielectric Properties ◽  
Vinylidene Fluoride ◽  
Average Particle Size ◽  
Hybrid Nanoparticles ◽  
Average Particle ◽  
Potential Measurement ◽  
Poly Vinylidene Fluoride ◽  
Negative Surface ◽  
Batio3 Nanoparticles

Poly(vinylidene fluoride) (PVDF) nanocomposites were fabricated by incorporating BaTiO3 nanoparticles (particle size of ~100 nm, nBT), which were deposited by Au nanoparticles (nAu) with an average particle size of 17.8 ± 4.0 nm using a modified Turkevich method. Systematic characterizations on the synthesized nAu-nBT hybrid nanoparticles and nAu-nBT/PVDF nanocomposites with different contents of a filler were performed. The formation of nAu-nBT hybrid nanoparticles was confirmed with the calculated nAu:nBT ratio of 0.5:99.5 wt.%. The homogeneous dispersion of nAu and nBT in the PVDF polymer was obtained due to the interaction between the negative surface charge of the nAu-nBT filler (compared to that of the nBT) and polar β-PVDF phase, which was confirmed by the zeta potential measurement and Fourier-transform infrared spectroscopy, respectively. A significantly increased dielectric permittivity (ε′ ~ 120 at 103 Hz) with a slight temperature-dependent of <±15% ranging from −20 to 140 °C was obtained. Notably, a low loss tangent (tanδ < 0.08) was obtained even at a high temperature of 140 °C. Therefore, incorporating a PVDF polymer with nAu-nBT hybrid nanoparticles is an attractive method to improve the dielectric properties of a PVDF polymer for dielectrics applications.

Synthesis and characterization of Cu-phthalocyanine hybrid TiO2 sol

2009 ◽  
Vol 13 (07) ◽  
pp. 779-786 ◽  
Author(s):  
Byeong Uk Jang ◽  
Jae Hong Choi ◽  
Sung Jun Lee ◽  
Se Geun Lee
Keyword(s):  
Particle Size ◽  
Irradiation Time ◽  
Sol Gel ◽  
Average Particle Size ◽  
Hybrid Nanoparticles ◽  
Average Particle ◽  
Oxygen Generation ◽  
Singlet Oxygen Generation ◽  
Tio2 Sol

TiO2 sol was prepared by a sol-gel method. Sodium polymethacrylate (PMAA) was added to TiO2 sol, resulting in a stable TiO2-PMAA . The copper(II) phthalocyanine tetrasulfonate ( CuPcTs ) was used to sensitize nanocrystalline TiO2 photocatalyst. The hybrid nanoparticles had an average particle size of 35 nm and core-shell type morphology was observed using a TEM. For the preparation of TiO2-CuPcTs , TiO2 was directly complexed with CuPcTs , leading to a particle size of 100 nm by a sonication treatment. The photodegradation of the hybrid type photosensitizer was measured using AO7 as an indicator with He-Ne laser with wavelength 633 nm. The efficiency of singlet oxygen generation was also measured by the reduction ratio of concentration of trans-1-(2′-methoxyvinyl) pyrene (MVP) responding to the change of fluorescene emission at 420 nm, depending on the irradiation time.

Poly(vinylidene fluoride)–La0.5Sr0.5CoO3−δ composites: the influence of LSCO particle size on the structure and dielectric properties

2014 ◽  
Vol 16 (32) ◽  
pp. 17008-17017 ◽  
Author(s):  
K. S. Deepa ◽  
P. Shaiju ◽  
M. T. Sebastian ◽  
E. Bhoje Gowd ◽  
J. James
Keyword(s):  
Particle Size ◽  
Dielectric Properties ◽  
Vinylidene Fluoride ◽  
Polar Crystals ◽  
Poly Vinylidene Fluoride ◽  
Embedded Capacitor

The inclusion of LSCO into PVDF readily favours the formation of polar crystals (β and γ-phases), which makes the composite suitable for embedded capacitor applications.

Improvement in dielectric properties of poly(vinylidene fluoride) by incorporation of Au–BiFeO3 hybrid nanoparticles

2020 ◽  
Vol 46 (11) ◽  
pp. 17272-17279
Author(s):  
Pornsawan Kum-onsa ◽  
Narong Chanlek ◽  
Bundit Putasaeng ◽  
Prasit Thongbai
Keyword(s):  
Dielectric Properties ◽  
Vinylidene Fluoride ◽  
Hybrid Nanoparticles ◽  
Poly Vinylidene Fluoride

scholarly journals Significantly improved dielectric properties of multiwall carbon nanotube-BaTiO3/PVDF polymer composites by tuning the particle size of the ceramic filler

RSC Advances ◽  
2019 ◽  
Vol 9 (41) ◽  
pp. 23498-23507 ◽  
Author(s):  
Kanyapak Silakaew ◽  
Prasit Thongbai
Keyword(s):  
Particle Size ◽  
Carbon Nanotube ◽  
Dielectric Properties ◽  
Electrical Properties ◽  
Polymer Composites ◽  
Vinylidene Fluoride ◽  
Multiwall Carbon Nanotube ◽  
Ceramic Filler ◽  
Poly Vinylidene Fluoride ◽  
Multiwall Carbon

The effects of different BaTiO3 sizes (≈100 nm (nBT) and 0.5–1.0 μm (μBT)) on the dielectric and electrical properties of multiwall carbon nanotube (CNT)-BT/poly(vinylidene fluoride) (PVDF) composites are investigated.

Determination of grinding parameters of fenugreek seed

1970 ◽  
Vol 26 (1) ◽  
pp. 16 ◽  
Author(s):  
S Balasubramanian ◽  
Rajkumar Rajkumar ◽  
K K Singh
Keyword(s):  
Particle Size ◽  
Energy Consumption ◽  
Moisture Content ◽  
Specific Energy ◽  
Feed Rate ◽  
Average Particle Size ◽  
Specific Energy Consumption ◽  
Average Particle ◽  
Fenugreek Seeds ◽  
Fenugreek Seed

Experiment to identify ambient grinding conditions and energy consumed was conducted for fenugreek. Fenugreek seeds at three moisture content (5.1%, 11.5% and 17.3%, d.b.) were ground using a micro pulverizer hammer mill with different grinding screen openings (0.5, 1.0 and 1.5 mm) and feed rate (8, 16 and 24 kg h-1) at 3000 rpm. Physical properties of fenugreek seeds were also determined. Specific energy consumptions were found to decrease from 204.67 to 23.09 kJ kg-1 for increasing levels of feed rate and grinder screen openings. On the other hand specific energy consumption increased with increasing moisture content. The highest specific energy consumption was recorded for 17.3% moisture content and 8 kg h-1 feed rate with 0.5 mm screen opening. Average particle size decreased from 1.06 to 0.39 mm with increase of moisture content and grinder screen opening. It has been observed that the average particle size was minimum at 0.5 mm screen opening and 8 kg h-1 feed rate at lower moisture content. Bond’s work index and Kick’s constant were found to increase from 8.97 to 950.92 kWh kg-1 and 0.932 to 78.851 kWh kg-1 with the increase of moisture content, feed rate and grinder screen opening, respectively. Size reduction ratio and grinding effectiveness of fenugreek seed were found to decrease from 4.11 to 1.61 and 0.0118 to 0.0018 with the increase of moisture content, feed rate and grinder screen opening, respectively. The loose and compact bulk densities varied from 219.2 to 719.4 kg m-3 and 137.3 to 736.2 kg m-3, respectively.  

Formulating SLN and NLC as Innovative Drug Delivery Systems for Non-Invasive Routes of Drug Administration

2020 ◽  
Vol 27 (22) ◽  
pp. 3623-3656 ◽  
Author(s):  
Bruno Fonseca-Santos ◽  
Patrícia Bento Silva ◽  
Roberta Balansin Rigon ◽  
Mariana Rillo Sato ◽  
Marlus Chorilli
Keyword(s):  
Drug Delivery ◽  
Particle Size ◽  
Drug Release ◽  
Drug Loading ◽  
Average Particle Size ◽  
Delivery Systems ◽  
Average Particle ◽  
Minor Importance ◽  
Routes Of Administration ◽  
Non Invasive

Colloidal carriers diverge depending on their composition, ability to incorporate drugs and applicability, but the common feature is the small average particle size. Among the carriers with the potential nanostructured drug delivery application there are SLN and NLC. These nanostructured systems consist of complex lipids and highly purified mixtures of glycerides having varying particle size. Also, these systems have shown physical stability, protection capacity of unstable drugs, release control ability, excellent tolerability, possibility of vectorization, and no reported production problems related to large-scale. Several production procedures can be applied to achieve high association efficiency between the bioactive and the carrier, depending on the physicochemical properties of both, as well as on the production procedure applied. The whole set of unique advantages such as enhanced drug loading capacity, prevention of drug expulsion, leads to more flexibility for modulation of drug release and makes Lipid-based nanocarriers (LNCs) versatile delivery system for various routes of administration. The route of administration has a significant impact on the therapeutic outcome of a drug. Thus, the non-invasive routes, which were of minor importance as parts of drug delivery in the past, have assumed added importance drugs, proteins, peptides and biopharmaceuticals drug delivery and these include nasal, buccal, vaginal and transdermal routes. The objective of this paper is to present the state of the art concerning the application of the lipid nanocarriers designated for non-invasive routes of administration. In this manner, this review presents an innovative technological platform to develop nanostructured delivery systems with great versatility of application in non-invasive routes of administration and targeting drug release.

Azithromycin nanosuspension preparation using evaporative precipitation into aqueous solution (EPAS) method and its comparative dissolution study

2020 ◽  
Vol 17 ◽  
Author(s):  
Mohammad Hossain Shariare ◽  
Tonmoy Kumar Mondal ◽  
Hani Alothaid ◽  
Md. Didaruzzaman Sohel ◽  
MD Wadud ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Dissolution Rate ◽  
Average Particle Size ◽  
Scale Up ◽  
Average Particle ◽  
Total Drug ◽  
Residual Solvent ◽  
Dissolution Study ◽  
Drug Content

Aim: EPAS (evaporative precipitation into aqueous solution) was used in the current studies to prepare azithromycin nanosuspensions and investigate the physicochemical characteristics for the nanosuspension batches with the aim of enhancing the dissolution rate of the nanopreparation to improve bioavailability. Methods: EPAS method used in this study for preparing azithromycin nanosuspension was achieved through developing an in-house instrumentation method. Particle size distribution was measured using Zetasizer Nano S without sample dilution. Dissolved azithromycin nanosuspensions were also compared with raw azithromycin powder and commercially available products. Total drug content of nanosuspension batches were measured using an Ultra-Performance Liquid Chromatography (UPLC) system with Photodiode Array (PDA) detector while residual solvent was measured using gas chromatography (GC). Results: The average particle size of azithromycin nanosuspension was 447.2 nm and total drug content was measured to be 97.81% upon recovery. Dissolution study data showed significant increase in dissolution rate for nanosuspension batch when compared to raw azithromycin and commercial version (microsuspension). The residual solvent found for azithromycin nanosuspension is 0.000098023 mg/ mL or 98.023 ppb. Conclusion: EPAS was successfully used to prepare azithromycin nanoparticles that exhibited significantly enhanced dissolution rate. Further studies are required to scale up the process and determine long term stability of the nanoparticles.

scholarly journals Evaluation of the Effects of Filler Fineness on the Properties of an Epoxy Asphalt Mixture

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2003
Author(s):  
Wei Xu ◽  
Jintao Wei ◽  
Zhengxiong Chen ◽  
Feng Wang ◽  
Jian Zhao
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Asphalt Mixture ◽  
Average Particle ◽  
Fine Dust ◽  
Bonding Structure ◽  
Epoxy Asphalt ◽  
Mineral Powder ◽  
Marshall Stability ◽  
Mixture Sample

The type and fineness of a filler significantly affect the performance of an asphalt mixture. There is a lack of specific research on the effects of filler fineness and dust from aggregates on the properties of epoxy asphalt (EA) mixtures. The effects of aggregate dust and mineral powder on the properties of an EA mixture were evaluated. These filler were tested to determine their fineness, specific surface area and mineral composition. The effects of these fillers on the EA mastic sample and mixture were evaluated. The morphology of the EA mastic samples was analyzed using scanning electron microscopy (SEM). The effects of the fillers on the Marshall stability, tensile strength and fatigue performance of the EA mixture were evaluated. The dust from the aggregates exhibited an even particle size distribution, and its average particle size was approximately 20% of that of the mineral powder. The SEM microanalysis showed that the EA mastic sample containing relatively fine dust formed a tight and dense interfacial bonding structure with the aggregate. The EA mixture sample containing filler composed of dust from aggregate had a significantly higher strength and longer fatigue life than that of the EA sample containing filler composed of mineral powder.

scholarly journals Surface Activity of Humic Acid and Its Sub-Fractions from Forest Soil

2021 ◽  
Vol 13 (15) ◽  
pp. 8122
Author(s):  
Shijie Tian ◽  
Weiqiang Tan ◽  
Xinyuan Wang ◽  
Tingting Li ◽  
Fanhao Song ◽  
...  
Keyword(s):  
Surface Tension ◽  
Particle Size ◽  
Humic Acid ◽  
Forest Soil ◽  
Surface Activity ◽  
Self Assembly ◽  
Average Particle Size ◽  
Gaussian Model ◽  
Exponential Model ◽  
Average Particle

Surface activity of humic acid (HA) and its six sub-fractions isolated from forest soil were characterized by surface tension measurements, dynamic light scattering, and laser doppler electrophoresis. The surface tension of HA and its sub-fractions reduced from 72.4 mN·m−1 to 36.8 mN·m−1 in exponential model with the increasing concentration from 0 to 2000 mg·L−1. The critical micelle concentration (CMC) and Z-average particle size ranged from 216–1024 mg·L−1 and 108.2–186.9 nm for HA and its sub-fractions, respectively. The CMC have related with alkyl C, O-alkyl C, aromatic C, and carbonyl C (p < 0.05), respectively, and could be predicted with the multiple linear regression equation of CMC, CMC = 18896 − 6.9 × C-296 × alkyl C-331 × aromatic C-17019 × H/C + 4054 × HB/HI (p < 0.05). The maximum particle size was 5000 nm after filtered by a membrane with pore size of 450 nm, indicating HA and its sub-fractions could progressed self-assembly at pH 6.86. The aggregate sizes of number-base particle size distributions were mainly in six clusters including 2 ± 1 nm, 5 ± 2 nm, 10 ± 3 nm, 21 ± 8 nm, 40 ± 10 nm, and >50 nm analyzed by Gaussian model that maybe due to the inconsistency of the components and structures of the HA sub-fractions, requiring further study. It is significance to explore the surface activity of HA and its sub-fractions, which is helpful to clarify the environmental behavior of HA.

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