scholarly journals Sub-micron sized saccharide fibres via electrospinning

2015 ◽  
Vol 1 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Pablo G. T. Lepe ◽  
Nick Tucker ◽  
Lyall Simmons ◽  
Andrew J. A. Watson ◽  
Antony J. Fairbanks ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Electrospinning Process ◽  
Supramolecular Polymers ◽  
Low Molecular Weight ◽  
Fibre Formation ◽  
Sugar Syrup ◽  
Glucose Syrup ◽  
Micron Diameter ◽  
Physical Entanglement

AbstractIn this work, the production of continuous submicron diameter saccharide fibres is shown to be possible using the electrospinning process. The mechanism for the formation of electrospun polymer fibres is usually attributed to the physical entanglement of long molecular chains. The ability to electrospin continuous fibre from a low molecular weight saccharides was an unexpected phenomenon. The formation of sub-micron diameter “sugar syrup” fibres was observed in situ using highspeed video. The trajectory of the electrospun saccharide fibre was observed to follow that typical of electrospun polymers. Based on initial food grade glucose syrup tests, various solutions based on combinations of syrup components, i.e. mono-, di- and tri-saccharides, were investigated to map out materials and electrospinning conditions thatwould lead to the formation of fibre. Thiswork demonstrated that sucrose exhibits the highest propensity for fibre formation during electrospinning amongst the various types of saccharide solutions studied. The possibility of electrospinning low molecular weight saccharides into sub-micron fibres has implications for the electrospinability of supramolecular polymers and other biomaterials.

scholarly journals Preparation of Porous Polymers by ”in Situ Precipitation” Using Low Molecular Weight Gelators

2002 ◽  
Vol 34 (6) ◽  
pp. 474-477 ◽  
Author(s):  
Masahiro Suzuki ◽  
Yasuhiko Sakakibara ◽  
Satoshi Kobayashi ◽  
Mutsumi Kimura ◽  
Hirofusa Shirai ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Porous Polymers ◽  
Low Molecular Weight ◽  
Low Molecular Weight Gelators

Instabilities in the System NMMO/Water/Cellulose (Lyocell Process) Caused by Polonowski Type Reactions

Holzforschung ◽  
2002 ◽  
Vol 56 (2) ◽  
pp. 199-208 ◽  
Author(s):  
Thomas Rosenau ◽  
Antje Potthast ◽  
Andreas Hofinger ◽  
Herbert Sixta ◽  
Paul Kosma
Keyword(s):  
Molecular Weight ◽  
Acetic Acid ◽  
Exchange Resin ◽  
Degradation Products ◽  
Ion Exchange Resin ◽  
Low Molecular Weight ◽  
Acid Component ◽  
Degradation Reactions ◽  
Polyglucuronic Acid

Summary Polonowski type degradation reactions are a major reason for the frequently observed instability of solutions of cellulose in N-methylmorpholine-N-oxide monohydrate (NMMO, 1). The degradation is induced by degradation products of cellulose and NMMO generated in situ in the Lyocell system. The presence of both an amine component, such as morpholine or N-methylmorpholine, and an acid component is required for the decomposition process to proceed. The latter might be a low-molecular-weight compound, such as formic acid, acetic acid or gluconic acid, or also a high-molecular-weight acid, such as polyglucuronic acid or ion exchange resin.

scholarly journals A simple method for the production of low molecular weight hyaluronan by in situ degradation in fermentation broth

e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 477-481
Author(s):  
Jianfeng Mei ◽  
Zhihong Dong ◽  
Yu Yi ◽  
Yanlu Zhang ◽  
Guoqing Ying
Keyword(s):  
Molecular Weight ◽  
Enzymatic Degradation ◽  
Fermentation Broth ◽  
Low Molecular Weight ◽  
Streptococcus Zooepidemicus ◽  
Medium Ph ◽  
Simple Method ◽  
Suitable Temperature ◽  
In Situ Degradation

AbstractFermentation of hyaluronan (HA) by Streptococcus zooepidemicus was carried out in a 10-L fermentor. When the medium pH was controlled at 7.0 and the temperature was maintained at 38°C for 12 h followed by 35°C for 8 h, the yield of HA was 4.83 g/L with a molecular weight of 1,890 kDa. After the cells were removed by centrifugation from the fermentation broth, HA was slowly degraded to low molecular weight HA by hyaluronidase at a suitable temperature without a decrease in HA concentration. If the time and temperature for enzymatic degradation were controlled, the desired low molecular weight HA could be obtained by in situ degradation in the fermentation broth. The method does not require the addition of exogenous hyaluronidase, and is a simple way to produce low molecular weight HA.

scholarly journals Multi Self-Healable UV Shielding Polyurethane/CeO2 Protective Coating: The Effect of Low-Molecular-Weight Polyols

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1947
Author(s):  
Mohammad Mizanur Rahman ◽  
Rami Suleiman ◽  
Md. Hasan Zahir ◽  
Aasif Helal ◽  
A. Madhan Kumar ◽  
...  
Keyword(s):  
Molecular Weight ◽  
In Situ Polymerization ◽  
Outdoor Exposure ◽  
Low Molecular Weight ◽  
Self Healing ◽  
Polydimethyl Siloxane ◽  
Molecular Weights ◽  
Uv Shielding ◽  
Ceo2 Coating

We prepared a series of polyurethane (PU) coatings with defined contents using poly(tetramethylene oxide)glycol (PTMG) with two different molecular weights (i.e., Mn = 2000 and 650), as well as polydimethyl siloxane (PDMS) with a molecular weight of Mn 550. For every coating, maximum adhesive strength and excellent self-healing character (three times) were found using 6.775 mol% mixed with low-molecular-weight-based polyols (PU-11-3-3). Defined 1.0 wt% CeO2 was also used for the PU-11-3-3 coating (i.e., PU-11-3-3-CeO2) to obtain UV shielding properties. Both the in situ polymerization and blending processes were separately applied during the preparation of the PU-11-3-3-CeO2 coating dispersion. The in situ polymerization-based coating (i.e., PU-11-3-3-CeO2-P) showed similar self-healing properties. The PU-11-3-3-CeO2-P coating also showed excellent UV shielding in real outdoor exposure conditions.

In situ formation of AuNPs using fatty N-acylamino hydrazide organogelators as templates

2019 ◽  
Vol 43 (1) ◽  
pp. 295-303 ◽  
Author(s):  
Renata Ongaratto ◽  
Naiane Conte ◽  
Caroline R. Montes D’Oca ◽  
Rafael C. Brinkerhoff ◽  
Caroline Pires Ruas ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gold Nanoparticles ◽  
Low Molecular Weight ◽  
In Situ Formation ◽  
First Time

This work reports, for the first time, the synthesis of new fatty N-acylamino hydrazides and demonstrates the activity of these compounds as low-molecular-weight organic gelators and templates for preparation of gold nanoparticles (AuNPs).

Nanolithography Using In-Situ Electron Beam Vaporization of Very Low Molecular Weight Resists

1981 ◽  
Vol 39 ◽  
pp. 372-373
Author(s):  
M. Isaacson ◽  
A. Muray
Keyword(s):  
Molecular Weight ◽  
Electron Beam ◽  
Nanometer Scale ◽  
Low Molecular Weight ◽  
Electron Sources ◽  
Incident Electron Beam ◽  
One Step ◽  
Beam Currents ◽  
Initial Pattern

We have begun a program of investigation of the suitability of very low molecular weiqht materials as electron beam resists for the development of structures on the nanometer scale. With the advent of reliable field emission source technology, electron sources can be produced that have brightnesses several orders of magnitude greater than existing thermionic sources. Thus, nanoamp beam currents are attainble in subnanometer diameter electron probes. This means that as little as a 10 μsec exposure is needed to deposit a dose of 1 C/cm2 in a sample. It therefore becomes reasonable to explore the ultimate limits of 1ithography, since different materials can be studied that are not necessarily as radiation sensitive as the standard high molecular weight resists (e.g., PMMA).Our explorations have centered on materials of molecular weight around 100 which could be readily vaporized under the action of the incident electron beam directly within an electron microscope ( 10-3 to 103 C/cm2). The initial pattern writing and development can then be done in one step.

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