Unravelling the role of polyols with increasing carbon chain length and OH groups on the phase transition behavior of PNIPAM

2018 ◽  
Vol 42 (16) ◽  
pp. 13708-13717 ◽  
Author(s):  
Payal Narang ◽  
Pannuru Venkatesu
Keyword(s):  
Phase Transition ◽  
Biomedical Research ◽  
Carbon Chain ◽  
Conformational Transitions ◽  
Carbon Chain Length ◽  
Phase Transition Behavior ◽  
Thermoresponsive Polymers ◽  
Oh Groups ◽  
Advanced Applications

In advanced applications of pharmaceutical, agricultural and biomedical research, thermoresponsive polymers (TRPs) are potential candidates which show conformational transitions at given temperatures.

The role of π-bonding on the high temperature structure of the double perovskites Ba2CaUO6and BaSrCaUO6

2015 ◽  
Vol 44 (36) ◽  
pp. 16036-16044 ◽  
Author(s):  
Emily Reynolds ◽  
Gordon J. Thorogood ◽  
Maxim Avdeev ◽  
Helen E. A. Brand ◽  
Qinfen Gu ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
Neutron Diffraction ◽  
Temperature Structure ◽  
Double Perovskites ◽  
Phase Transition Behavior ◽  
X Ray ◽  
Progressive Loss ◽  
Octahedral Tilting

High temperature synchrotron X-ray and neutron diffraction powder diffraction studies of the uranium perovskites Ba2CaUO6and BaSrCaUO6reveal unusual phase transition behavior associated with the progressive loss of cooperative octahedral tilting.

The formation and destruction of pentenes during the combustion of pentane

1978 ◽  
Vol 364 (1716) ◽  
pp. 75-88 ◽  
Keyword(s):  
Chain Length ◽  
Sharp Decrease ◽  
Carbon Chain ◽  
Carbon Chain Length ◽  
Reactivity Ratios ◽  
Direct Products ◽  
Specific Activities ◽  
Kinetics Of ◽  
Quantitative Importance

Studies have been made of the quantitative rôle of pent-1-ene and pent-2-ene in the combustion of pentane at temperatures below 400°C. The present results show that, under these conditions, pentenes are initial and direct products of pentane combustion and pent-2-ene is the principal conjugate alkene formed [1- 14 C]Pent-1-ene and [2- 14 C]pent-2-ene have been synthesized and the combustion of pentane has also been investigated in the presence of small concentrations of these specifically labelled com­pounds; control experiments have shown that the pentenes, in the amounts added, do not interfere appreciably with the kinetics of pentane combustion. Measurements of the variation with time of the specific activities and concentrations of the pentenes enable the separate rates of formation and destruction of the conjugate alkenes to be determined. Hence it is possible to calculate the total quantities of these compounds formed at different stages of reaction and to show to what extent these are greater than the net amounts revealed by conventional analytical measurements; the differences are found to be most marked at small conversions. The reactivity ratios of pentane and the pentenes have also been determined. The rates of destruction of both pentenes are much greater than that of pentane; pent-2-ene is removed from the system roughly twice as fast as pent-1-ene. An important contrast between the behaviour of pentane and butane is that, between 300 and 400°C, but-1-ene is a much more abundant product than but-2-ene. However, with both alkanes, the relative amounts of the alk-1-enes formed become greater as the temperature is increased; indeed, the rate of formation of pent-1-ene considerably exceeds that of pent-2-ene at the instant of the passage of a strong cool flame. Comparison of the total amounts of conjugate alkenes formed from the two alkanes at 315°C shows that only ca . 30% of the pentane consumed is converted to pentenes, whereas nearly 75% of the butane which has reacted is converted to butenes. Thus there is clearly a sharp decrease in the quantitative importance of conjugate alkenes as the carbon chain length is increased from C 4 to C 5 . This suggests that the predominant reaction of pentyl radicals, under the conditions used, is to add on oxygen to form pentylperoxy radicals.

scholarly journals The Role of Hydrogen Bond Donor on the Extraction of Phenolic Compounds from Natural Matrices Using Deep Eutectic Systems

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2336
Author(s):  
Duarte Rente ◽  
Alexandre Paiva ◽  
Ana Rita Duarte
Keyword(s):  
Hydrogen Bond ◽  
Phenolic Compounds ◽  
Comprehensive Evaluation ◽  
Critical Role ◽  
Carbon Chain ◽  
Carbon Chain Length ◽  
Carbonyl Groups ◽  
Hydrogen Bond Donor ◽  
Eutectic Systems

Recently, deep eutectic systems (DESs) as extraction techniques for bioactive compounds have surfaced as a greener alternative to common organic solvents. In order to study the effect of these systems on the extraction of phenolic compounds from different natural sources, a comprehensive review of the state of the art was carried out. In a first approach, the addition of water to these systems and its effect on DES physicochemical properties such as polarity, viscosity, and acidity was investigated. This review studied the effect of the hydrogen bond donor (HBD) on the nature of the extracted phenolics. The effects of the nature of the HBD, namely carbon chain length as well as the number of hydroxyl, methyl, and carbonyl groups, have shown to play a critical role in the extraction of different phenolic compounds. This review highlights the differences between DES systems and systematizes the results published in the literature, so that a more comprehensive evaluation of the systems can be carried out before any experimental trial.

Role of Molecular Structure of Complexing/Chelating Agents in Copper CMP Slurries

2005 ◽  
Vol 867 ◽  
Author(s):  
Udaya B. Patri ◽  
S. Pandija ◽  
S.V. Babu
Keyword(s):  
Molecular Structure ◽  
Functional Groups ◽  
Chelating Agents ◽  
Carbon Chain ◽  
Carbon Chain Length ◽  
Removal Rates ◽  
Ph Values ◽  
Amino Butyric Acid ◽  
Acidic Conditions

AbstractThe role of the molecular structure - different functional groups, the length of the carbon chain and the relative positions of different functional groups – of several complexing/chelating agents (acetic acid, glycine, ethylene diamine, succinic acid, alanine and amino butyric acid (ABA)) in controlling copper (Cu) removal rates was investigated. The results are consistent with the known activity of –COOH groups at acidic conditions and that of –NH2 groups in an alkaline environment. In comparison with glycine, it was also observed that an increase in the carbon chain length increased the removal rates at acidic pH values and decreased the removal rates at alkaline pH values. Also, Cu removal rates decreased with an increase in the distance between the –NH2 and –COOH groups in an amino acid at all pH values except at 4.

The role of unique spatial structure in the volume phase transition behavior of poly(N-isopropylacrylamide)-based interpenetrating polymer network microgels including a thermosensitive poly(ionic liquid)

2018 ◽  
Vol 20 (12) ◽  
pp. 8077-8087 ◽  
Author(s):  
Lan Ma ◽  
Peiyi Wu
Keyword(s):  
Phase Transition ◽  
Ionic Liquid ◽  
Spatial Structure ◽  
Phase Behavior ◽  
Polymer Network ◽  
Interpenetrating Polymer Network ◽  
Volume Phase Transition ◽  
Phase Transition Behavior ◽  
Poly Ionic Liquid

By comparing with the linear homopolymer mixture, the influence of spatial structure on the phase behavior of thermosensitive interpenetrating polymer network (IPN) microgels was clarified.

scholarly journals Role of the charge, carbon chain length, and content of surfactant on the skin penetration of meloxicam-loaded liposomes

2014 ◽  
pp. 2005 ◽  
Author(s):  
Sureewan Duangjit ◽  
Praneet Opanasopit ◽  
Theerasak Rojanarata ◽  
Yasuko Obata ◽  
Kozo Takayama ◽  
...  
Keyword(s):  
Chain Length ◽  
Skin Penetration ◽  
Carbon Chain ◽  
Carbon Chain Length
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