Effect of ultraviolet irradiation on the stability and antifriction properties of polymeric materials

1974 ◽  
Vol 8 (6) ◽  
pp. 705-707
Author(s):  
I. Ya. Al'shits ◽  
L. M. Semenova
Keyword(s):  
Ultraviolet Irradiation ◽  
Polymeric Materials ◽  
Antifriction Properties ◽  
The Stability

scholarly journals Evaluation of the Stability of Polymeric Materials Exposed to Palm Biodiesel and Biodiesel–Organic Acid Blends

Polymers ◽  
2018 ◽  
Vol 10 (5) ◽  
pp. 511 ◽  
Author(s):  
Libia Baena ◽  
Ernesto Zuleta ◽  
Jorge Calderón
Keyword(s):  
Organic Acid ◽  
Polymeric Materials ◽  
The Stability

scholarly journals Cellulose Acetate Fabrics Loaded with Rhodamine B Hydrazide for Optical Detection of Cu(II)

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3751
Author(s):  
Rania E. Morsi ◽  
Moataz Elsawy ◽  
Ilse Manet ◽  
Barbara Ventura
Keyword(s):  
Porous Structure ◽  
Cellulose Acetate ◽  
Rhodamine B ◽  
Polymeric Materials ◽  
Emission Analysis ◽  
Absorption And Emission ◽  
Sensing Applications ◽  
Phase Inversion Technique ◽  
The Stability ◽  
Rhodamine B Hydrazide

In this work, different materials were fabricated from cellulose acetate, loaded with rhodamine B hydrazide and tested as Cu(II) optical sensor. We prepared membranes displaying a sub-micron porous structure using the phase inversion technique, clusters of fibers with varying diameter depending on the preparation procedure using electrospinning, and casted films presenting a smooth non porous structure. Loading of rhodamine B hydrazide on the fabrics after their production was found to be the best procedure to ensure the stability of the dye in the polymeric materials. Absorption and emission analysis of the solid substrates revealed the presence of the dye on the porous fabrics and allowed to choose the most suited materials and loading conditions to test their response towards Cu(II) ions. Reaction of the loaded rhodamine B hydrazide with Cu(II) was confirmed by absorption and emission spectroscopies and by confocal fluorescence imaging, through detection of the product rhodamine B. The results point to promising sensing applications of the prepared composite materials.

scholarly journals STUDIES OF MOUSE POLYOMA VIRUS INFECTION

1959 ◽  
Vol 109 (5) ◽  
pp. 439-447 ◽  
Author(s):  
Isadore Brodsky ◽  
Wallace P. Rowe ◽  
Janet W. Hartley ◽  
William T. Lane
Keyword(s):  
Tissue Culture ◽  
Ethyl Alcohol ◽  
Ultraviolet Irradiation ◽  
Horse Serum ◽  
Virus Titer ◽  
Basal Medium ◽  
Culture Fluid ◽  
Polyoma Virus ◽  
The Stability ◽  
Infectivity Titer

Mouse polyoma virus was stored at 4° and –60°C. for 8 weeks without any loss in hemagglutination or infectivity titer; storage at 37° for 8 weeks reduced infectivity titer by approximately 2.5 log10 units. Repeated freezing and thawing of infectious tissue culture fluid had no effect on virus titer. The stability of the virus to storage for 1 week at 4°C. was unaffected by suspension of infected tissue culture fluid in saline, demineralized distilled water, or 5 per cent horse serum in Eagle's basal medium. Heating the virus for 30 minutes at 60°C. had no effect on infectivity and hemagglutination titers. Heating at 65°C. for 30 minutes produced a 3 log unit loss of infectivity and a 4-fold decline in HA titer, and heating at 70°C. for 30 minutes usually produced complete inactivation of infectivity and HA. The virus was resistant to ultraviolet irradiation; ultraviolet irradiation for 2 hours caused a 4 log unit decrease in infectivity titer without affecting the HA titer. The virus was resistant to exposure to 2 per cent phenol and 50 per cent ethyl alcohol but was inactivated by 100 per cent ethyl alcohol, and ethyl alcohol-iodine mixtures. Lyophilization had no effect on the stability of the virus.

scholarly journals Application of Complex Chitosan Hydrogels Added With Canola Oil in Partial Substitution of Cocoa Butter in Dark Chocolate

2020 ◽  
Vol 4 ◽  
Author(s):  
Andres Silvestre Gallegos Soto ◽  
Renata Santos Rabelo ◽  
Eliana Marcela Vélez-Erazo ◽  
Paulo Túlio de Souza Silveira ◽  
Priscilla Efraim ◽  
...  
Keyword(s):  
Cocoa Butter ◽  
Canola Oil ◽  
Polymer Concentration ◽  
Saturated Fat ◽  
Polymeric Materials ◽  
Fat Content ◽  
Dark Chocolate ◽  
Partial Substitution ◽  
Retention Capacity ◽  
The Stability

The complexation of polymeric materials can be an alternative to trapping oil in a physical network for formulating foods with reduced saturated fat content. In this research, we have evaluated the use of different polymer ratios of Sodium Alginate (ALG), Carrageenan predominance iota (CR1) and Carrageenan predominance kappa (CR2) complexed with Chitosan (CHI) at a fixed polymer concentration (2% w/v) to formulate complex hydrogels and assess their oil holding capacity. The objective was to determine the polymer ratios of CHI to anionic polysaccharides (75:25, 50:50, and 25:75), determining the oil retention capacity in different ratios, and how this can affect the stability, microstructure and rheology of to produce low saturated chocolate with trapped canola oil. The stability of the hydrogels was characterized, considering the water retention and retention of canola oil in polysaccharides complexes. The more stable system was the hydrogel CHI:CR2 in a polymer ratio of 25:75. This formulation, when added of 20% of canola oil presented an apparent viscosity of 0.631 Pa.s at 300 s−1, and its use as replacer of saturated fat allowed the production of dark chocolate with 16% reduction in fat content and 80% of added cocoa butter. Stability studies showed that polysaccharides complexes network can retain the edible oil in chocolate formulation for 60 days. It has been proven that polysaccharides complexes can be incorporated to partially replace the fatty phase in chocolates without considerable changes in relevant characteristics as consumer acceptance evaluated by sensory tests and rheological properties.

REACTIONS OF ORGANOTIN COMPOUNDS: I. THE STABILITY OF DIMETHYLTIN DIHYDRIDE, AND ADDITIONS TO SOME FLUORO-OLEFINS

1963 ◽  
Vol 41 (11) ◽  
pp. 2889-2897 ◽  
Author(s):  
H. C. Clark ◽  
Sharon G. Furnival ◽  
J. T. Kwon
Keyword(s):  
Ultraviolet Light ◽  
Ultraviolet Irradiation ◽  
Chemical Properties ◽  
Addition Product ◽  
Organotin Compounds ◽  
Physical And Chemical Properties ◽  
Decomposition Products ◽  
The Stability ◽  
Physical And Chemical ◽  
And Chemical Properties

The effect of heat and ultraviolet irradiation on dimethyltin dihydride is reported. At 120°, the major decomposition products are (CH3)3SnH, Sn, and H2, with a small amount of (CH3)6Sn2. At 130° under ultraviolet light, decomposition is much more rapid giving (CH3)3SnH, Sn, and H2, and an appreciable quantity of (CH3) 4Sn. If the dihydride is maintained under these conditions for a longer period (40 hours), (CH3)6Sn2 is formed in place of (CH3)3SnH, and other products are (CH3)4Sn, Sn, and H2. Negligible decomposition occurs at 25° even under irradiation.The ready addition of C2F4 to (CH3)2SnH2 gives the first reported mono-addition product of an organotin dihydride, (CH3)2SnH(C2F4H), as well as (CH3)2Sn(C2F4H)2. Physical and chemical properties of these compounds are described. The additions of (CH3)2SnH2 to CF2CFH, CF2CH2, and CF2CFBr are reported and the results interpreted in terms of the formation of unstable mono-addition products, (CH3)2SnH(C2FnXmHp). Surprisingly, these species decompose through the exchange of halogen and hydrogen between (CH3)2SnH2 and the olefin. Thus, usual products from the reaction of (CH3)2SnH2 with CF2CFBr are (CH3)2SnBr2 and CF2CFH, with some (CH3)3SnBr.

Reactions of organotin compounds. IX. The reactions of tin hydrides with perfluorovinyl germanium and tin compounds

1968 ◽  
Vol 46 (12) ◽  
pp. 2165-2173 ◽  
Author(s):  
M. Akhtar ◽  
H. C. Clark
Keyword(s):  
Free Radical ◽  
Ultraviolet Irradiation ◽  
Spectroscopic Data ◽  
Addition Product ◽  
Tin Compounds ◽  
Radical Process ◽  
Organogermanium Compounds ◽  
The Stability ◽  
Derivatives Of ◽  
Free Radical Process

The formation of addition products (CH3)3MCFHCF2Sn(CH3)3 and (CH3)3MCF[Sn(CH3)3]CF2H where M = Ge or Sn has been observed in reactions involving the ultraviolet irradiation of (CH3)3MCF=CF2 with trimethyltin hydride. The former type of addition product is more stable than the latter, and the stability of both types decreases in the order M = Si, Ge, or Sn. Evidence is presented that decomposition occurs in all cases by a β-fiuorine elimination with the formation of fluorovinyl derivatives of M and trimethyltin fluoride. Similar reactions occur between (CH3)3GeCF=CF2 and dimethyltin dihydride and between (CH3)2Ge(CF=CF2)2 and dimethyltin dihydride or trimethyltin hydride. The evidence indicates that a free radical process is involved. Spectroscopic data are presented for new organogermanium compounds.

Sign in / Sign up

Export Citation Format

Share Document