Mesoporous polystyrene-based microspheres with polar functional surface groups synthesized from double emulsion for selective isolation of acetoside

2021 ◽  
pp. 462720
Author(s):  
Yanyan Hao ◽  
Helin Xu ◽  
Xueqin Li ◽  
Zhong Wei ◽  
Yan Zhang
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Shahid Amin ◽  
Abaid Ur Rehman Virk ◽  
M.A. Rehman ◽  
Nehad Ali Shah

Dendrimers are highly branched, star-shaped macromolecules with nanometer-scale dimensions. Dendrimers are defined by three components: a central core, an interior dendritic structure (the branches), and an exterior surface with functional surface groups. Topological indices are numerical numbers that help us to understand the topology of different dendrimers and can be used to predict the properties without performing experiments in the wet lab. In the present paper, we computed the Sombor index and the reduced version of the Sombor index for the molecular graphs of phosphorus-containing dendrimers, porphyrin-cored dendrimers, PDI-cored dendrimers, triazine-based dendrimers, and aliphatic polyamide dendrimers. We also plotted our results by using Maple 2015 which help us to see the dependence of the Sombor index and reduced Sombor index on the involved parameters. Our results may help to develop better understanding about phosphorus-containing dendrimers, porphyrin-cored dendrimers, PDI-cored dendrimers, triazine-based dendrimers, and aliphatic polyamide dendrimers. Our results are also useful in the pharmaceutical industry and drug delivery.


2012 ◽  
Vol 50 (12) ◽  
pp. 852-862 ◽  
Author(s):  
Konstantin I. Popov ◽  
Rikkert J. Nap ◽  
Igal Szleifer ◽  
Monica Olvera de la Cruz

1997 ◽  
Vol 121-122 ◽  
pp. 372-377 ◽  
Author(s):  
E.I. Iiskola ◽  
S. Timonen ◽  
T.T. Pakkanen ◽  
O. Härkki ◽  
J.V. Seppälä

2006 ◽  
Vol 15 (03) ◽  
pp. 188-196
Author(s):  
S. Brosch ◽  
M. Shehata ◽  
G. Hofbauer ◽  
M. Peterlik ◽  
P. Pietschmann

2018 ◽  
Author(s):  
Pierre Marcasuzaa ◽  
Samuel Pearson ◽  
Karell Bosson ◽  
Laurence Pessoni ◽  
Jean-Charles Dupin ◽  
...  

A hierarchically structured platform was obtained from spontaneous self-assembly of a poly(styrene)-<i>b</i>-poly(vinylbenzylchloride) (PS-<i>b</i>-PVBC) block copolymer (BCP) during breath figure (BF) templating. The BF process using a water/ethanol atmosphere gave a unique double porosity in which hexagonally arranged micron-sized pores were encircled by a secondary population of smaller, nano-sized pores. A third level of structuration was simultaneously introduced between the pores by directed BCP self-assembly to form out-of-the-plane nano-cylinders, offering very rapid bottom-up access to a film with unprecedented triple structure which could be used as a reactive platform for introducing further surface functionality. The surface nano-domains of VBC were exploited as reactive nano-patterns for site-specific chemical functionalization by firstly substituting the exposed chlorine moiety with azide, then “clicking” an alkyne by copper (I) catalyzed azide-alkyne Huisgen cycloaddition (CuAAC). Successful chemical modification was verified by NMR spectroscopy, FTIR spectroscopy, and XPS, with retention of the micro- and nanostructuration confirmed by SEM and AFM respectively. Protonation of the cyclotriazole surface groups triggered a switch in macroscopic behavior from a Cassie-Baxter state to a Wenzel state, highlighting the possibility of producing responsive surfaces with hierarchical structure.


2018 ◽  
Vol 84 (11) ◽  
pp. 23-27
Author(s):  
M. I. Degtev ◽  
A. A. Yuminova ◽  
A. S. Maksimov ◽  
A. P. Medvedev

The possibility of using an aqueous stratified system of antipyrine — sulfosalicylic acid — water for the selective isolation of scandium macro- and microquantities for subsequent determination is studied. The proposed extraction system eliminates the usage of toxic organic solvents. The organic phase with a volume of 1.2 to 2.0 ml, resulting from delamination of the aqueous phase containing antipyrine and sulfosalicylic acid is analysed to assess the possibility of using such systems for metal ions extraction. Condition necessary for the formation of such a phase were specified: the ratio of the initial components, their concentration, presence of inorganic salting out agents. The optimum ratio of antipyrine to sulfosalicylic acid is 2:1 at concentrations of 0.6 and 0.3 mol/liter in a volume of the aqueous phase of 10 ml. The obtained phase which consists of antipyrinium sulfosalicylate, free antipyrine and water, quantitatively extracts macro- and microquantities of scandium at pH = 1.54. Macro- and microquantities of yttrium, terbium, lanthanum, ytterbium and gadolinium are not extracted under the aforementioned conditions thus providing selective isolation of scandium from the bases containing yttrium, ytterbium, terbium, lanthanum, and gadolinium.


2020 ◽  
pp. 179-181
Author(s):  
A.A. Abrashov A.A. ◽  
E.G. Vinokurov ◽  
M.A. Egupova ◽  
V.D. Skopintsev

The technological (deposition rate, coating composition) and functional (surface roughness, microhardness) characteristics of chemical composite coatings Ni—Cu—P—Cr2O3 obtained from weakly acidic and slightly alkaline solutions are compared. It is shown that coatings deposited from slightly alkaline solution contain slightly less phosphorus and chromium oxide than coatings deposited from weakly acid solution (2...3 % wt. phosphorus and up to 3.4 % wt. chromium oxide), formed at higher rate (24...25 microns per 1 hour of deposition at temperature of 80 °C), are characte rized by lower roughness and increased microhardness. The Vickers microhardness at 0.05 N load of composite coatings obtained from slightly alkaline solution and heat-treated at 400 °C for 1 hour is 13.5...15.2 GPa, which is higher than values for coatings deposited made of weakly acidic solution. The maximum microhardness of coatings is achieved at concentration 20 g/l of Cr2O3 particles. The technology of chemical deposition of Ni—Cu—P—Cr2O3 coatings formed in slightly alkaline solution is promising for obtaining of materials with increased hardness and wear resistance.


1984 ◽  
Vol 5 (2) ◽  
pp. 187-194 ◽  
Author(s):  
SATORU KANEKO ◽  
SHIGERU OSHIO ◽  
TOSHIFUMI KOBAYASHI ◽  
HIDEO MOHRI ◽  
RIHACHI IIZUKA

Author(s):  
M. A. Tit ◽  
S. N. Belyaev

This article considers the research results of the effect of stoichiometry on the properties of titanium nitride thin-film coatings of the float and electrostatic gyroscopes. It presents the results of tests of such mechanical and optical characteristics of titanium nitride thin-film structures as microhardness, resistance to wear and friction, and image contrast determined by the reflection coefficients of a titanium nitride base surface and a raster pattern formed by local laser oxidation. When making a rotor of a cryogenic gyroscope, the prospects of use and technological methods for the formation of functional surface structures of niobium carbide and nitride are considered. It is shown that during the formation of coatings of the required composition, the most important is the thermodynamic estimation of possible interactions. These interactions allow us to accomplish the structural-phase modification of the material, which is determined by the complex of possible topochemical reactions leading to the formation of compounds, including non-stoichiometric composition.


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