scholarly journals A finger-jointing model for describing nanostructures of cellulose microfibrils

2021 ◽  
Author(s):  
Bunshi Fugetsu ◽  
Adavan Kiliyankil Vipin ◽  
Shoichi Takiguchi ◽  
Ichiro Sakata ◽  
Morinobu Endo
Keyword(s):  
Water Vapor ◽  
Sustainable Development Goals ◽  
Cellulose Nanofibers ◽  
Cellulose Microfibrils ◽  
Cellulose Nanowhiskers ◽  
Saturated Water Vapor ◽  
Native Cellulose ◽  
Saturated Water ◽  
Development Goals ◽  
Finger Jointing

Abstract We propose a finger-jointing model to describe the possible nanostructures of native cellulose microfibrils based on new observations obtained through thermal decomposition of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidized cellulose nanofibers (CNFs) in saturated water vapor. We heated the micrometers-long TEMPO-CNFs in saturated water vapor (≥ 120 °C, ≥ 0.2 MPa) for ≤ 8 h. The long TEMPO-CNFs unzipped into short (100 s of nanometers long) cellulose nanowhiskers (CNWs). We characterized the CNWs using Raman spectroscopy and Fourier transform infrared spectroscopy, observing similar spectra as TEMPO-CNFs. Thus, the native cellulose microfibrils are not seamlessly long structures, but serial “jointed structures” of CNWs. The finger-jointing model implies a “working and resting rhythm” in the biosynthesis of cellulose. CNWs are highly dispersible in water and polar organic solvents, and are much easier to combine with other classes of polymers at nano-levels. The findings can enhance the feasibility and applicability of native cellulose to achieve sustainable development goals.

scholarly journals A finger-jointing model for describing ultrastructures of cellulose microfibrils

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bunshi Fugetsu ◽  
Vipin Adavan Kiliyankil ◽  
Shoichi Takiguchi ◽  
Ichiro Sakata ◽  
Morinobu Endo
Keyword(s):  
Water Vapor ◽  
Cellulose Nanofibrils ◽  
Cellulose Microfibrils ◽  
Saturated Water Vapor ◽  
X Ray Diffraction ◽  
Saturated Water ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Long Fibers ◽  
Finger Jointing

AbstractIn this paper, we propose a finger-jointing model to describe the possible ultrastructures of cellulose microfibrils based on new observations obtained through heating of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidized cellulose nanofibrils (CNFs) in saturated water vapor. We heated the micrometers-long TEMPO-CNFs in saturated water vapor (≥ 120 °C, ≥ 0.2 MPa) and observed a surprising fact that the long TEMPO-CNFs unzipped into short (100 s of nanometers long) fibers. We characterized the heated TEMPO-CNFs using X-ray diffraction (XRD) and observed the XRD patterns were in consistent with Iβ. We observed also jointed ultrastructures on the heated TEMPO-CNFs via high-resolution transmission electron microscopy (HR-TEM). Thus we concluded that cellulose microfibrils are not seamlessly long structures, but serial jointed structures of shorter blocks. Polysaccharide chains of the short blocks organized in Iβ. The jointed region can be either Iα or amorphous, depending on positions and distances among the chains jointed in proximity. Under heating, Iα was not converted into Iβ but was simply destroyed. The jointed structure implies a “working and resting rhythm” in the biosynthesis of cellulose.

Generation of aerosol and droplets in binary mixtures of saturated water vapor with air and molecular gases

2016 ◽  
Vol 29 (2) ◽  
pp. 127-134 ◽  
Author(s):  
A. V. Klimkin ◽  
A. N. Kuryak ◽  
Yu. N. Ponomarev ◽  
A. S. Kozlov ◽  
S. B. Malyshkin ◽  
...  
Keyword(s):  
Water Vapor ◽  
Binary Mixtures ◽  
Saturated Water Vapor ◽  
Molecular Gases ◽  
Saturated Water

Pyrolytic Deposition of MnO2 Layers in Saturated Water Vapor Atmospheres

1980 ◽  
Vol 127 (10) ◽  
pp. 2180-2181 ◽  
Author(s):  
J. M. Albella ◽  
L. Fernández‐Navarrete ◽  
J. M. Martínez‐Duart
Keyword(s):  
Water Vapor ◽  
Saturated Water Vapor ◽  
Saturated Water

scholarly journals New technological and technical solutions in dietary pear compote production

2020 ◽  
Vol 161 ◽  
pp. 01056
Author(s):  
Magomed Akhmetov ◽  
Amiiat Demirova ◽  
Vladimir Piniaskin ◽  
R.A. Rakhmanova
Keyword(s):  
Water Vapor ◽  
Traditional Method ◽  
Raw Materials ◽  
Hot Water ◽  
Saturated Water Vapor ◽  
High Quality ◽  
Saturated Water ◽  
Preliminary Preparation ◽  
Physical And Chemical

Perfection of technological processes, both in preliminary preparation of raw materials and during the final mandatory step of pasteurization, plays a key role in ensuring the quality of finished products, which is important in the production of canned dietary products. The aim of the research was to develop a more efficient way of blanching raw materials with its hardware and soft pasteurization modes, which will allow the production of high quality and competitive compotes for functional nutrition. We have developed and proposed a method of pulse-steam blanching of raw materials directly in glass jars with saturated water vapor, instead of the traditional method using hot water. The essence of the method is as follows. Fruits stacked in jars are pulse heated for 100–160 seconds (depending on the volume of the container) with saturated water vapor with temperature of 105–110 °C, and then fed into jars with cycles of 10 and 10 seconds respectively. The use of pulsed supply of saturated water vapor contributes to achieving more even heating of the fruit, which are characterized by a relatively large internal thermal resistance, causing overheating of the surface layers, and also provides an increase in the temperature of the product, which allows to pour into the jars syrup at relatively high temperature (97–98 °C), while the traditional technology accounts for the temperature of only 80–85 °C. Implementation of this method ensures the temperature level of the product entering the pasteurization stage being 78–80 °C, as opposed to the traditional method, where the temperature of the product is 45–48 °C. After that, the jars will be filled with syrup with a temperature of 97–98 °C, sealed and sent for pasteurization on accelerated modes. To implement the new method of blanching, the design of the device for pulse-steam blanching of fruits in glass jars has been developed. New thermal sterilization regimes have been developed, taking into account the increased temperature of the product after sealing and improved technology for the production of pear compote. The results of physical and chemical testing confirm the high quality of the finished product.

Heat capacity and cluster structure of saturated water vapor

2014 ◽  
Vol 88 (9) ◽  
pp. 1450-1455 ◽  
Author(s):  
N. P. Malomuzh ◽  
P. V. Makhlaichuk ◽  
S. V. Khrapatyi
Keyword(s):  
Heat Capacity ◽  
Water Vapor ◽  
Cluster Structure ◽  
Saturated Water Vapor ◽  
Saturated Water

scholarly journals Raman Spectra from Saturated Water Vapor to the Supercritical Fluid

2001 ◽  
Vol 105 (29) ◽  
pp. 7155-7156 ◽  
Author(s):  
G. E. Walrafen ◽  
W.-H. Yang ◽  
Y. C. Chu
Keyword(s):  
Water Vapor ◽  
Raman Spectra ◽  
Supercritical Fluid ◽  
Saturated Water Vapor ◽  
Saturated Water
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