Preparation and Characterization of Novel Acrylate Emulsiones with Ketone-Hydrazide Crosslinking Structure Based on Application of Reactive Emulsifier

2013 ◽  
Vol 833 ◽  
pp. 335-338
Author(s):  
Zhen Wu ◽  
Chong Zhe Zhong ◽  
Yu Song ◽  
Ying Qiang Zhang

Polyacrylate emulsions (PAs) with core-shell structure were prepared by semi-continuous emulsion polymerization with diacetone acrylamide (DAAM) and adipic dihydrazide (ADH) as crosslinkable monomers and compound emulsifier system of SDS/0P-21/MS-1, reactive emulsifier NRS-10 as emulsifier respectively. The polyacrylate emulsion with keto-hydrazide crosslinking was characterized by Fourier transform infrared spectroscopy (FTIR), FTIR analyses demonstrated that the keto-hydrazide crosslinking reaction occur in the emulsion. The properties of both emulsions and films were tested by size analysis, viscosity analysis and others. The results showed that the average particle size with reactive emulsifier system of around 93 nm, coagulation rate of around 0.81% and water absorption rate of around 6.7% and the quality of polyacrylate emulsion with reactive emulsifier system was excellent.

2013 ◽  
Vol 12 (1) ◽  
pp. 31-37
Author(s):  
Priya L

A ZnS nanoparticle doped with Mn2+ is synthesized in aqueous media and PVA using chemical co-precipitation method. This colloid was analyzed using uv-vis spectrophotometry. It is observed that the absorption peak blue shifts as compared to the bulk absorption of ZnS suggesting the nanoparticle formation. The energy gaps of these nanoparticles were calculated from the uv-vis spectra. The average particle size analysis is carried out using XRD. Photoluminescence of PVA/ ZnS:Mn2+ is studied. It is observed that the composite sample exhibits an orange emission peak as is reported for pure ZnS: Mn2+.


2011 ◽  
Vol 415-417 ◽  
pp. 617-620 ◽  
Author(s):  
Yan Su ◽  
Ying Yun Lin ◽  
Yu Li Fu ◽  
Fan Qian ◽  
Xiu Pei Yang ◽  
...  

Water-soluble gold nanoparticles (AuNPs) were prepared using 2-mercapto-4-methyl-5- thiazoleacetic acid (MMTA) as a stabilizing agent and sodium borohydride (NaBH4) as a reducing agent. The AuNPs product was analyzed by transmission electron microscopy (TEM), UV-vis absorption spectroscopy and Fourier transform infrared spectroscopy (FTIR). The TEM image shows that the particles were well-dispersed and their average particle size is about 5 nm. The UV-vis absorption and FTIR spectra confirm that the MMTA-AuNPs was stabilized by the carboxylate ions present on the surface of the AuNPs.


Author(s):  
Mohammed Sabar Al-lami ◽  
Malath H. Oudah ◽  
Firas A. Rahi

This study was carried out to prepare and characterize domperidone nanoparticles to enhance solubility and the release rate. Domperidone is practically insoluble in water and has low and an erratic bioavailability range from 13%-17%. The domperidone nanoparticles were prepared by solvent/antisolvent precipitation method at different polymer:drug ratios of 1:1 and 2:1 using different polymers and grades of poly vinyl pyrolidone, hydroxy propyl methyl cellulose and sodium carboxymethyl cellulose as stabilizers. The effect of polymer type, ratio of polymer:drug, solvent:antisolvent ratio, stirring rate and stirring time on the particle size, were investigated and found to have a significant (p? 0.05) effect on particle size. The best formula was obtained with lowest average particle size of 84.05. This formula was studied for compatibility by FTIR and DSC, surface morphology by FESEM and crystalline state by XRPD. Then domperidone nanoparticles were formulated into a simple capsule dosage form in order to study of the in vitro release of drug from nanoparticles in comparison raw drug and mixture of polymer:drug ratios of 2:1. The release of domperidone from best formula was highly improved with a significant (p? 0.05) increase.


2021 ◽  
Vol 10 ◽  
Author(s):  
Venkata Subbaiah Kotakadi ◽  
Bhulakshmi Kolapalli ◽  
Susmila Aparna Gaddam ◽  
Sai Gopal Divi Venkata Ramana

Background: There is an increasing commercial demand for nanoparticles due to their wide applicability in various areas such as chemistry, catalysis, energy and medicine. Metallic nanoparticles are traditionally synthesized by wet chemical techniques where the chemicals used are quite often toxic and flammable. Objective: In the present study, we described a simple, cost effective and environmentally-friendly technique for green synthesis of silver and iron nanoparticles by using the aqueous extract of leafy vegetable Amaranthus viridis as a reducing agent. Methods: The silver and Iron nanoparticles (Av-AgNPs, Av-IONPs) were characterized by different spectral methods. The surface Plasmon resonance spectrums of Av-AgNPs, Av-IONPs were recorded at 422nm and 261nm. The Scanning electron microscopy (SEM) analysis reveals that the Av-AgNPs, Av-IONPs are roughly spherical in shape. Energy dispersive absorption spectroscopy (EDAX) of biosynthesized Av-AgNPs, Av-IONPs indicates the reduction of silver ions to elemental silver and iron ions to elemental iron. Results: The particle size analysis of Av-AgNPs and Av-IONPs was carried out by Dynamic light scattering (DLS) method the results reveal that both Av-AgNPs and Av-IONPs were polydispered in nature. The average particle size of Av-AgNPs is 55.8 nm with a polydispered index (PI) of 0.297, similarly the average particle size of Av-IONPs is 80.6 nm with an polydispered index (PI) of 0.469. Zeta-potential of Av-AgNPs was detected at -24.6 mV and Av-IONPs were detected at 28.8 mV, the result reveals that they high stability due their high negative charge and positive charge respectively. The dual synthesized Av-AgNPs, Av-IONPs exhibits excellent antioxidant activity by DPPH, H2O2 and NO methods. DPPH was proven to be the best when compared with the other two methods. The biosynthesized Av-AgNPs, Av-IONPs proved to have very good antimicrobial activity against gram +ve and gram –ve bacteria. Conclusion: when compared with standard antibiotic. There were several reports on green synthesis of metal nanoparticles using various plant parts, but here edible leafy vegetable Amaranthus viridis was used for biosynthesis of both Av-AgNPs and Av-IONPs.


2010 ◽  
Vol 5 (3) ◽  
pp. 155892501000500 ◽  
Author(s):  
D.P. Chattopadhyay ◽  
B.H. Patel

This research deals with the synthesis of nanosized copper as colloidal solution and its application to cotton fabric. Copper nano colloids were prepared by chemical reduction of copper salt using sodium borohydride as reducing agent in presence of tri-sodium citrate. The size and size distribution of the particles were examined by particle size analyzer and the morphology of the synthesized particles was examined by SEM and AFM techniques. X-ray fluorescence spectroscopy detected the presence of copper in the treated fabric. The results of particle size analysis showed that the average particle size varied from 60 nm to 100 nm. The nano copper treated cotton was subjected to soil burial test for the assessment of its resistance towards microbial attack. SEM images of treated fabric indicate copper nano particles are well dispersed on the surface of the specimens. The treatments of nano copper colloidal solution on cotton not only improve its antimicrobial efficiency but also influenced the tensile strength of the fabric sample positively. The treatment was found to enhance the color depth and fastness properties of direct dyed cotton fabric samples.


2018 ◽  
Vol 10 (1) ◽  
pp. 338
Author(s):  
Rachmawati Ramadhana Mustofa ◽  
Iskandarsyah .

Objective: This study aimed to prepare and characterize anti-acne ethosomes using the cold- and thin-layer hydration methods.Methods: A sonication step was included during ethosome preparation to improve the quality of the cold method. Azelaic acid, Phospholipon 90G,ethanol, propylene glycol, and phosphate buffer (pH 7.4) were used in the procedures. Prepared ethosomal suspensions were characterized usingtransmission electron microscopy, particle-size analysis, and spectrophotometry.Results: Ethosomes prepared using the thin-layer hydration method (F1) had small unilamellar vesicles, while those prepared using the cold methodwith 15-min sonication (F4) showed spherical, elliptical, unilamellar, and multilamellar vesicles. F1 ethosomes had a Dmean volume of 648.57±231.26,whereas those prepared using the cold method with 5- (F2), 10- (F3), and 15-min (F4) sonication had Dmean volumes of 2734.04±231.49 nm,948.90±394.52 nm, and 931.69±471.84 nm, respectively. Polydispersity indices of F2, F3, and F4 ethosomes were 0.74±0.21, 0.86±0.05, and 0.91±0.03,respectively, with a poor particle-size distribution, compared to that of F1 (0.39±0.01). Zeta potentials of F1–F4 ethosomes were −38.27±1.72 mV,−23.53±1.04 mV, −31.4±1.04 mV, and −34.3±1.61 mV, respectively. Entrapment efficiencies of F1–F4 ethosomes were 90.71±0.11%, 53.84±3.16%,72.56±0.28%, and 75.11±1.42%, respectively.Conclusion: Anti-acne ethosomes produced using the thin-layer hydration method had superior properties than those produced using the coldmethod with 15-min sonication.


2014 ◽  
Vol 798-799 ◽  
pp. 355-359 ◽  
Author(s):  
Valter Bezerra Dantas ◽  
U.U. Gomes ◽  
A.B. Vital ◽  
G.S. Marinho ◽  
Ariadne de Souza Silva

This paper presents the results of tests for characterization of soil samples collected in Mossoró-RN, UFERSA-RN Campus (5 ° 12'34 .68 "South latitude, 37 ° 19 '5.74 "west longitude), for the purpose of producing soil-cement for the manufacture of pressed blocks. Objective of improving the quality of soil-cement, and provide conditions for the use of the soil making it ideal for the production of soil-cement block. Tests of compaction, particle size analysis, plastic limit, liquid limit and correct particle size, X-ray fluorescence and morphology by scanning electron microscopy (SEM). It was concluded that the soil needs correction particle size, due to the high clay content. The method combined grading, sieving, sedimentation and blooming X-ray as the fastest and most accurate in correcting soil particle size.


2011 ◽  
Vol 10 (03) ◽  
pp. 487-493 ◽  
Author(s):  
K. VIJAI ANAND ◽  
R. MOHAN ◽  
R. MOHAN KUMAR ◽  
M. KARL CHINNU ◽  
R. JAYAVEL

Cerium-doped ZnS nanoparticles have been synthesized through hydrothermal method. The nanoparticles were stabilized using hexamethylenetetramine (HMTA) as surfactant in aqueous solution. The average particle size of the prepared samples is about 2 nm. The structure of the as-prepared ZnS nanoparticles is cubic (zinc blende) as demonstrated by X-ray powder diffraction (XRD) and selected area electron diffraction (SAED) analysis. TEM results showed that the synthesized nanoparticles were uniformly dispersed in the HMTA matrix without aggregation. The UV–Vis absorption spectra of the prepared ZnS nanoparticles show a considerable blueshift in the absorption band edge compared to bulk ZnS indicating a strong quantum confinement effect. Formation of HMTA-capped ZnS nanoparticles was confirmed by FTIR studies. Photoluminescence studies showed that the relative emission intensity of Ce3+ -doped ZnS nanoparticles is higher than that of undoped ZnS nanoparticles, which is due to the enhancement of radiative recombination in the luminescence process. The PL spectra showed two emission peaks at around 420 nm and 442 nm, which may be attributed to deep-trap emission or defect-related emission of ZnS and presence of various surface states.


2017 ◽  
Vol 263 ◽  
pp. 165-169
Author(s):  
Silvia Chowdhury ◽  
Faridah Yusof ◽  
Nadzril Sulaiman ◽  
Mohammad Omer Faruck

In this article, we have studied the process of silver nanoparticles (AgNPs) aggregation and to stop aggregation 0.3% Polyvinylpyrrolidone (PVP) was used. Aggregation study carried out via UV-vis spectroscopy and it is reported that the absorption spectrum of spherical silver nanoparticles were found a maximum peak at 420 nm wavelength. Furthermore, Transmission Electron Microscopy (TEM) were used to characterized the size and shape of AgNPs, where the average particle size is around 10 to 25 nm in diameter and the AgNPs shape is spherical. Next, Dynamic Light Scattering (DLS) were used, owing to observed size distribution and self-correlation of AgNPs.


2016 ◽  
Vol 18 (2) ◽  
pp. 131-139
Author(s):  
Kinga Łuczka ◽  
Barbara Grzmil ◽  
Bogumił Kic ◽  
Krzysztof Kowalczyk

Abstract Synthesis and characterization of the aluminum phosphates modified with ammonium, calcium and molybdenum were conducted. The influence of process parameters (reactive pressure and molar ratios) in the reaction mixture were studied. The contents of the individual components in the products were in the range of: 10.97–17.31 wt% Al, 2.65–13.32 wt% Ca, 0.70–3.11 wt% Mo, 4.36–8.38 wt% NH3, and 35.12–50.54 wt% P2O5. The materials obtained in the experiments were characterized by various physicochemical parameters. The absorption oil number was in the range from 67 to 89 of oil/100 g of product, the surface area was within the range of 4–76 m2/g, whereas the average particle size of products reached 282–370 nm. The Tafel tests revealed comparable anticorrosive properties of aluminum phosphates modified with ammonium, calcium, molybdenum in comparison with commercial phosphate.


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