Ultrahigh yield synthesis of mesoporous carbon nanoparticles as a superior lubricant additive for polyethylene glycol

2020 ◽  
Vol 49 (16) ◽  
pp. 5283-5290 ◽  
Author(s):  
Zihao Mou ◽  
Baogang Wang ◽  
Zhiyu Huang ◽  
Hongsheng Lu

Mesoporous carbon nanoparticles (MCNPs) with an average particle size of 27.3 nm and a pore size of 3–5 nm were facilely synthesized in ultrahigh yield (91.7 wt%) and used as a high-performance lubricant additive for polyethylene glycol (PEG200).

2019 ◽  
Vol 19 (02) ◽  
pp. 1950014
Author(s):  
Sabereh Nazari ◽  
Sadegh Nazari ◽  
Fariba Mansourizadeh ◽  
Gholamreza Karimi

In this study, high purity gamma-alumina nanopowders with crystalline structures have been prepared via a sol–gel process by waste metal aluminum, HCl, NaOH, Polyethylene glycol (PEG) and polyvinyl alcohol (PVA). Polyethylene glycol and polyvinyl alcohol have been used as stabilizing agents. The characterization of the samples has been performed utilizing XRD, FTIR, SEM, N2 adsorption/desorption techniques. Prepared samples of gamma-alumina at 800∘C with PEG has an average crystallite size of 2.58[Formula: see text]nm, average particle size of 21[Formula: see text]nm, specific surface area (SSA) of 65.55[Formula: see text]m2/g, and pore volume of [Formula: see text]0.06[Formula: see text]cm3/g. The average crystallite size of 3.07[Formula: see text]nm, average particle size of 31[Formula: see text]nm, specific surface area of 131.25[Formula: see text]m2/g, and pore volume of [Formula: see text]0.14[Formula: see text]cm3/g, were obtained using PVA surfactant.


2020 ◽  
Vol 4 (5) ◽  
pp. 2220-2228 ◽  
Author(s):  
Xueying Dong ◽  
Yifu Zhang ◽  
Qiang Chen ◽  
Hanmei Jiang ◽  
Qiushi Wang ◽  
...  

Nanotailoring of active manganese silicate with an average particle size of about 20 nm is realized by an ammonia-etching-assisted route, delivering a 3.55-times higher faradaic capacity than the traditional yolk–shell counterpart in hybrid supercapacitors.


2013 ◽  
Vol 32 (5) ◽  
pp. 511-515 ◽  
Author(s):  
Xiao Guo Cao ◽  
Jia Wang ◽  
Qi Bai Wu ◽  
Hai Yan Zhang

AbstractYb:YAG transparent ceramic nano-powder was prepared by chemical co-precipitation method, with ammonium bicarbonate as the precipitant and polyethylene glycol as surfactant. The addition of polyethylene glycol can reduce the agglomeration and particle size of the prepared Yb:YAG powder. The morphology, thermal stability and phase structure of Yb:YAG nano-powder were charactered by scanning electron microscopy (SEM), thermogravimetry and differential thermal analysis (TG-DTA), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy. The results show that well-crystallized nano-powder was obtained by calcining the precursors at 900 °C for 3 h. The average particle size of Yb:YAG powder is about 100–200 nm. When the volume amount of polyethylene glycol is 2.0%, well-dispersed Yb:YAG powder with spherical particles of 100 nm diameter was obtained.


2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yanting Lou ◽  
Wei He ◽  
Zhengyao Song

With the increasing incidence and recurrence rate of urinary calculi, urinary calculi have become a serious health risk, and the research on urinary calculi has become the focus of public attention. At present, the research results on the formation mechanism of urinary calculi are not ideal, and there is no unified conclusion. In order to further study the influencing factors of the formation of urinary calculi and provide new ideas for the prevention and clinical treatment of urinary calculi, the influence of agglomeration of nanochemical microcrystals in urine on urinary calculi was studied in this paper. In this study, fresh morning urine was collected from 10 urological stone patients and 10 healthy controls without urological stone in the urology department of a hospital. After processing the experimental specimens, we first use flame atomic absorption spectrometry and alcian blue colorimetric method to detect the content of Ca2+ and citrate in the urine and then use the nanoparticle size analyzer to detect the microcrystals in the urine. Diameter, distribution, degree of aggregation and potential, and finally HRTEM observation to observe the morphology, chemical composition, and element composition of the nanocrystals. The results showed that the content of Ca2+ and lemon hydrochloric acid in the urine of the experimental group was lower than that of the control group. The particle size of the nanocrystals increased with the increase in the pore size of the membrane. The average particle size of the experimental group increased gradually from 163 ± 31 nm to 3219 ± 863 nm, while the average particle size of the control group increased from 183 ± 65 nm to 997 ± 522 nm. The mean value of the potential decreased with the increase in the pore size of the filter membrane. The change amplitude of the experimental group was 6.57 mV, while the change amplitude of the control group was only 1.75 mV. In the composition of nanocrystals, element O accounts for the most, accounting for 42.54% of all elements. This indicates that the aggregation of nanocrystals in urine will lead to the rapid increase in the size of nanocrystals, which will eventually lead to the formation of stones.


2004 ◽  
Vol 19 (4) ◽  
pp. 1087-1092 ◽  
Author(s):  
Naofumi Uekawa ◽  
Masayuki Ueta ◽  
Yong Jun Wu ◽  
Kazuyuki Kakegawa

Cerium oxide (CeO2) nanoparticles were obtained by heating a polyethylene glycol (PEG) solution of cerium nitrate hydrate [Ce(NO3)3 6H2O] at 383 K for 3 h. When the PEG, whose molecular weight was 20,000, was used for the preparation, the monodispersed CeO2, whose particle size was about 102 nm, was obtained. When the mixture of PEG20,000 and ethylene glycol (EG) was used to prepare the PEG solution of cerium nitrate hydrate, the average particle size increased from 102 nm to 660 nm with an increase in the EG content of the solution. The pore structure in the obtained CeO2 particles also depended on the weight ratio between EG and PEG20,000.


2014 ◽  
Vol 804 ◽  
pp. 209-212 ◽  
Author(s):  
Pusit Pookmanee ◽  
Isara Phiwchai ◽  
Sorachon Yoriya ◽  
Ratchadaporn Puntharod ◽  
Supaporn Sangsrichan ◽  
...  

Titanium dioxide (TiO2) nanopowder was prepared by the low temperature solvothermal route with starting chemicals containing titanium isopropoxide, ammonium hydroxide, nitric acid and ethanol in a PTFE–lined autoclave. The final pH of the mixed solution was 1 and treated at 100 °C for 2–6 h. The white precipitated was filtered and dried in an oven at 80 °C for 24 h. The phase transition was characterized by X–ray diffractometer (XRD). Single phase anatase structure was obtained without calcination step. The morphology and particle size of TiO2nanopowder was investigated by scanning electron microscope (SEM). The average of TiO2nanopowder size was 80–120 nm. The average particle size increased with temperature and time increased. The photocatalytic degradation of methomyl in natural water was studied by high performance liquid chromatograph (HPLC). The percentage of methomyl was decreased in the presence of 34, 23 and 24 over TiO2nanopowder prepared by the low temperature solvothermal route at 100 °C for 2, 4 and 6 h, respectively.


2021 ◽  
Author(s):  
Ralandinliu Kahmei ◽  
Papori Seal ◽  
Jyoti Prasad Borah

We report a high performance magnetic nanoparticle as hyperthermic agent under low applied field and frequency. CTAB (cetyltrimethylammonium bromide)-coated NixZn1-xFe2O4 nanoparticles of average particle size < 25 nm with various...


2021 ◽  
Vol 13 (8) ◽  
pp. 1557-1564
Author(s):  
Yayan Zhou ◽  
Minjie Fang ◽  
Dong Yang ◽  
Maosheng Yan ◽  
Long Gong ◽  
...  

This work aimed to analyze expression mechanism of micro ribonucleic acid (RNA)-10b (miR-10b) in cervical cancer (CC) based on Curcumin-monomethoxy polyethylene glycol-polylactic acid-drug-loaded nanoparticles (CUR-MPEG-PLA DLNPs). 36 Kunming mice were selected and randomly rolled into group A and group B, and 18 nude mice were deemed as controls. CUR-MPEG-PLA DLNPs were prepared for the treatment of 18 Kunming mice in group A. The CC tumor tissues of 36 Kunming mice were harvested, the miR-10b of CC cells was extracted, and the expression level of CC cells was detected by fluorescence quantitative polymerase chain reaction (qPCR). The results showed that the average particle size of CUR-MPEG-PLA DLNPs was 362.52±6.34 nm. The tumor inhibition rate of Kunming mice in group A against CC tumor strains 63.35±3.62% was considerably superior to those in group B (26.31 ±2.54%) (P < 0.05). In group A, expression rate of miR-10b (77.78%) was remarkably superior to controls (55.55%) (x2 = 2.364, P < 0.05). In 20 cases of CC tissues with positive expression of latent membrane protein 1 (LMP-1), expression of miR-10b in metastasis group was obviously higher relative to non-metastasis group (Z = −3.214, P < 0.05). In 16 cases of CC tissues with negative expression of LMP-1, expression of miR-10b in metastasis group was also considerably higher versus non-metastasis group (Z = −2.245, P < 0.05). In conclusion, the average particle size of CUR-MPEG-PLA DLNPs was 362.52 ±6.34 nm, the electromotive force was −9.23 mV, the dispersion coefficient was 0.064, the drug loading rate of nanoparticles was 8.54%, and the encapsulation rate was 72.36%. miR-10b has certain correlation with the metastasis of cervical cancer. LMP-1 gene has the function of promoting the metastasis of cervical cancer tumor cells, which may be dependent on miR-10b. CUR-MPEG-PLA DLNPs loading system can inhibit tumor growth obviously, and has excellent therapeutic effect in CC disease.


Author(s):  
SUTRIYO SUTRIYO ◽  
RADITYA ISWANDANA ◽  
FIRDA MARETHA IVARIANI

Objective: Gold nanoparticles (AuNPs) can be used as targeted drug delivery systems, however, AuNPs have high surface energy and easily aggregate,thus negatively impacting nanoparticle stability. Therefore, it is necessary to add a stabilizing agent to AuNPs. To synthesize AuNPs stabilized bypolyethylene glycol conjugated to folic acid (FA), thus creating a model drug (resveratrol [RSV]) carrier that targets FA receptors on cancer cells.Methods: AuNPs were synthesized using the Turkevich method and stabilized by adding FA conjugated to polyethylene glycol (PEG). After RSV wasloaded, the conjugate was physically characterized and subjected to stability tests.Results: The RSV-AuNP had an average particle size of 51.97 nm (polydispersity index [PDI] 0.694, zeta potential – 24.6 mV). The RSV-AuNP-PEG-FAconjugate (RSV-AuNP-PEG-FA) had an average particle size of 195.6 nm (PDI=0.233, zeta potential=−21.1 mV). Stability tests showed that RSV-AuNPPEG-FA was more stable than RSV-AuNP. Furthermore, RSV-AuNP-PEG-FA and RSV-AuNP were more stable in buffer pH 7.4 and bovine serum albumin2% than in buffer pH 4, cysteine 1%, and NaCl 0.9% solutions.Conclusion: PEG-FA conjugates can improve the stability of RSV-loaded AuNP.


1970 ◽  
Vol 26 (1) ◽  
pp. 16 ◽  
Author(s):  
S Balasubramanian ◽  
Rajkumar Rajkumar ◽  
K K Singh

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.  


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