scholarly journals Comparative Study on Different Modified Preparation Methods of Cellulose Nanocrystalline

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3417
Author(s):  
Xinhui Wang ◽  
Na Wang ◽  
Baoming Xu ◽  
Yili Wang ◽  
Jinyan Lang ◽  
...  
Keyword(s):  
Graft Polymerization ◽  
Surface Active Substance ◽  
Esterification Reaction ◽  
Hydrophobic Properties ◽  
Grafting Polymerization ◽  
Preparation Methods ◽  
Modification Process ◽  
Surface Active ◽  
Polymerization Method ◽  
Modified Cellulose

Different modification process routes are used to improve the modified cellulose nanocrystalline (MCNC) with higher fatty acid by esterification reaction and graft polymerization to obtain certain hydrophobic properties. Two preparation methods, product structure and surface activity, are compared and explored. Experimental results show that the modified product is still at the nanometer level and basically retains the crystal structure of the raw cellulose nanocrystalline (CNC). The energy consumption of the two preparation methods is low; however, the esterification method with co-reactant requires short reaction time, and the degree of substitution of the product is high. The modified product prepared by grafting polymerization method has a high HLB value and amphiphilicity, which can effectively reduce the surface tension of water. Therefore, it can be used as a green and environmentally friendly surface-active substance.

scholarly journals INFLUENCE OF SPEED, TIME OF HOMOGENIZATION, TYPE OF SURFACE ACTIVE SUBSTANCE ON THE SIZE OF PENTOXYPHILLINE NANOPARTICLES BASED ON POLY-DL-LAKTIDE-CO-GLICOLIDE

2017 ◽  
Vol 5 (2) ◽  
pp. 177-194 ◽  
Author(s):  
T. V. Timchenko ◽  
A. V. Blinov ◽  
A. V. Serov ◽  
L. I. Shcherbakova ◽  
V. A. Kompantsev ◽  
...  
Keyword(s):  
Active Substance ◽  
Surface Active Substance ◽  
Surface Active

scholarly journals THE ROLE OF WATER IN PROTOPLASMIC PERMEABILITY AND IN ANTAGONISM

1956 ◽  
Vol 39 (6) ◽  
pp. 963-976 ◽  
Author(s):  
W. J. V. Osterhout
Keyword(s):  
Surface Layer ◽  
Water Content ◽  
Active Substance ◽  
External Medium ◽  
Surface Active Substance ◽  
Potassium Ions ◽  
Protoplasmic Surface ◽  
Outer Protoplasmic Surface ◽  
Aqueous Surface ◽  
Surface Active

The behavior of the cell depends to a large extent on the permeability of the outer non-aqueous surface layer of the protoplasm. This layer is immiscible with water but may be quite permeable to it. It seems possible that a reversible increase or decrease in permeability may be due to a corresponding increase or decrease in the water content of the non-aqueous surface layer. Irreversible increase in permeability need not be due primarily to increase in the water content of the surface layer but may be caused chiefly by changes in the protoplasm on which the surface layer rests. It may include desiccation, precipitation, and other alterations. An artificial cell is described in which the outer protoplasmic surface layer is represented by a layer of guaiacol on one side of which is a solution of KOH + KCl representing the external medium and on the other side is a solution of CO2 representing the protoplasm. The K+ unites with guaiacol and diffuses across to the artificial protoplasm where its concentration becomes higher than in the external solution. The guaiacol molecule thus acts as a carrier molecule which transports K+ from the external medium across the protoplasmic surface. The outer part of the protoplasm may contain relatively few potassium ions so that the outwardly directed potential at the outer protoplasmic surface may be small but the inner part of the protoplasm may contain more potassium ions. This may happen when potassium enters in combination with carrier molecules which do not completely dissociate until they reach the vacuole. Injury and recovery from injury may be studied by measuring the movements of water into and out of the cell. Metabolism by producing CO2 and other acids may lower the pH and cause local shrinkage of the protoplasm which may lead to protoplasmic motion. Antagonism between Na+ and Ca++ appears to be due to the fact that in solutions of NaCl the surface layer takes up an excessive amount of water and this may be prevented by the addition of suitable amounts of CaCl2. In Nitella the outer non-aqueous surface layer may be rendered irreversibly permeable by sharply bending the cell without permanent damage to the inner non-aqueous surface layer surrounding the vacuole. The formation of contractile vacuoles may be imitated in non-living systems. An extract of the sperm of the marine worm Nereis which contains a highly surface-active substance can cause the egg to divide. It seems possible that this substance may affect the surface layer of the egg and cause it to take up water. A surface-active substance has been found in all the seminal fluids examined including those of trout, rooster, bull, and man. Duponol which is highly surface-active causes the protoplasm of Spirogyra to take up water and finally dissolve but it can be restored to the gel state by treatment with Lugol solution (KI + I). The transition from gel to sol and back again can be repeated many times in succession. The behavior of water in the surface layer of the protoplasm presents important problems which deserve careful examination.

Kinetics of the formation and structure of oligoperoxide nanolayers and grafted polymer brushes on glass plate surface

Open Physics ◽  
2008 ◽  
Vol 6 (3) ◽  
Author(s):  
Andriy Kostruba ◽  
Alexander Zaichenko ◽  
Natalya Mitina ◽  
Kateryna Rayevska ◽  
Kateryna Hertsyk
Keyword(s):  
Polymer Brushes ◽  
Graft Polymerization ◽  
Glass Plate ◽  
Flat Plates ◽  
Hydrophobic Properties ◽  
Surface Protection ◽  
Grafted Polymer ◽  
Coating Formation ◽  
Modified Surface ◽  
Kinetics Of

AbstractFunctional oligoperoxide surfactants and coordinating oligoperoxide metal complexes were studied as modifiers of glass flat plates to provide the localization of radical forming sites and other functional fragments in adsorbed polymeric layers of a nanoscale thickness. Both the kinetics of the coating formation and properties of the nanolayers witness the dependence of the packing density of oligoperoxide molecules in the coatings on the oligoperoxide natures, concentrations and conditions of the sorption modification. The availability of definite amount of peroxide groups in formed nanolayer provides the possibility of controlled radical graft polymerization initiated from modified surface leading to reliable surface protection, functionality and targeted surface hydrophilic-hydrophobic properties.

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