scholarly journals Evaluation of self-prepared absorbable hemostatic cellulose fibrils

2021 ◽  
Author(s):  
Lingshuang WANG ◽  
Jianxing TONG ◽  
Zhezhe ZHAO ◽  
Xiaochun YANG
Keyword(s):  
Cellulose Fibrils

Enzymatic Hydrolysis Combined with Mechanical Shearing and High-Pressure Homogenization for Nanoscale Cellulose Fibrils and Strong Gels

2007 ◽  
Vol 8 (6) ◽  
pp. 1934-1941 ◽  
Author(s):  
M. Pääkkö ◽  
M. Ankerfors ◽  
H. Kosonen ◽  
A. Nykänen ◽  
S. Ahola ◽  
...  
Keyword(s):  
High Pressure ◽  
Enzymatic Hydrolysis ◽  
High Pressure Homogenization ◽  
Cellulose Fibrils ◽  
Mechanical Shearing

scholarly journals Effect of Gluconacetobacter xylinus cultivation conditions on the selected properties of bacterial cellulose

2016 ◽  
Vol 18 (4) ◽  
pp. 117-123 ◽  
Author(s):  
Karol Fijałkowski ◽  
Anna Żywicka ◽  
Radosław Drozd ◽  
Marian Kordas ◽  
Rafał Rakoczy
Keyword(s):  
Bacterial Cellulose ◽  
Bacterial Strain ◽  
Point Of View ◽  
Synthesis Process ◽  
Cellulose Synthesis ◽  
Gluconacetobacter Xylinus ◽  
Water Release ◽  
Good Efficiency ◽  
Cellulose Fibrils ◽  
Culturing Conditions

Abstract The aim of the study was to analyze the changes in the parameters of bacterial cultures and bacterial cellulose (BC) synthesized by four reference strains of Gluconacetobacter xylinus during 31-day cultivation in stationary conditions. The study showed that the most visible changes in the analyzed parameters of BC, regardless of the bacterial strain used for their synthesis, were observed in the first 10–14 days of the experiment. It was also revealed, that among parameters showing dependence associated with the particular bacterial strain were the rate and period of BC synthesis, the growth rate of bacteria anchored to the cellulose fibrils, the capacity to absorb water and the water release rate. The results presented in this work may be useful in the selection of optimum culturing conditions and period from the point of view of good efficiency of the cellulose synthesis process.

The Structure of the Column in Stylidium

1989 ◽  
Vol 37 (1) ◽  
pp. 81 ◽  
Author(s):  
N Findlay ◽  
GP Findlay
Keyword(s):  
Internal Structure ◽  
Small Groups ◽  
Central Layer ◽  
Wide Range ◽  
Single Column ◽  
Cellulose Fibrils ◽  
Shape And Size ◽  
Fast Firing

In the genus Stylidium, the style and filaments of the flower are fused into a single column. In most species the column, when stimulated mechanically, undergoes a fast firing movement followed by a slow resetting movement. This movement is produced by changes in shape of a normally curved region of the column, the bend. In a wide range of species, the bend has a specialised anatomy and consists essentially of a longitudinal central layer of cells with two distinctive multi-celled layers of thick-walled cells on either side. The thick-walled cells are rich in cytoplasm with amyloplasts and vacuoles of varying sizes, and have non-lignified walls whose cellulose fibrils are arranged approximately transversely. Within the bend, the phloem occurs as discrete small groups of cells separated by some distance from the xylem. In species from the subgenus Centridium both the morphology and the internal structure of the bend differ somewhat from those in most species of Stylidium, and in two species of Stylidium with nonmoving columns, the characteristic cellular anatomy of the bend is entirely absent. The specialised anatomy of the cells and tissues in the bend are clearly associated with the movement of the column. Changes of shape and size of these cells are almost certainly responsible for the change in shape of the bend.

Effective Young’s Modulus of Bacterial and Microfibrillated Cellulose Fibrils in Fibrous Networks

2012 ◽  
Vol 13 (5) ◽  
pp. 1340-1349 ◽  
Author(s):  
Supachok Tanpichai ◽  
Franck Quero ◽  
Masaya Nogi ◽  
Hiroyuki Yano ◽  
Robert J. Young ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Microfibrillated Cellulose ◽  
Cellulose Fibrils

scholarly journals Flame Retardancy of High-Density Polyethylene Composites with P,N-Doped Cellulose Fibrils

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 336 ◽  
Author(s):  
Shuai Zhang ◽  
He Chen ◽  
Yin Zhang ◽  
Yi-meng Zhang ◽  
Weiyan Kan ◽  
...  
Keyword(s):  
Flame Retardancy ◽  
High Density Polyethylene ◽  
High Density ◽  
One Pot ◽  
Peak Heat Release Rate ◽  
Cellulose Fibrils ◽  
Acid Catalyzed ◽  
Lower Temperature ◽  
Cellulose Surface ◽  
Phosphate Groups

To derive P,N-doped cellulose fibrils, phosphoric acid and aqueous ammonia were placed in a one-pot reaction, and the phosphate groups and ammonium phosphates were successfully introduced into the cellulose surface. The obtained P,N-doped cellulose fibrils with high liberation were thereafter incorporated into a high-density polyethylene (HDPE) matrix to improve the flame retardancy of HDPE composites, and they had a significant improvement on flame retardancy of HDPE composites. In particular, 7 wt % P,N-doped cellulose fibrils considerably reduced the average and peak heat release rate (HRR) by 29.6% and 72.9%, respectively, and increased the limited oxygen index (LOI) by 30.5%. The presence of phosphate groups and ammonium phosphates within P,N-doped cellulose fibrils was found to promote the thermal degradation of HDPE composites at a lower temperature (i.e., 240 °C). The released acid catalyzed the dehydration of cellulose to form an aromatic carbonaceous structure with a higher crystalline orientation, which improves the flame retardancy of HDPE composites.

Probing the chemical and surface chemical modification of vessel cell walls during bleaching of eucalyptus pulp

Holzforschung ◽  
2012 ◽  
Vol 66 (8) ◽  
pp. 945-950 ◽  
Author(s):  
Elina Orblin ◽  
Nina Lindström ◽  
Pedro Fardim
Keyword(s):  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Wall Structure ◽  
Surface Chemical ◽  
Major Drawback ◽  
Elemental Chlorine ◽  
Eucalyptus Pulp ◽  
Vessel Elements ◽  
Cellulose Fibrils ◽  
Bulk Chemical

Abstract Eucalyptus pulp is increasingly used for the manufacture of printing papers. However, its major drawback, the vessel picking, is still waiting for a solution. The detailed features and the characteristic behaviour of vessel elements (VEs) in pulp and paper processes are poorly understood. This study focusses on the chemistry, surface chemistry and morphology of eucalyptus VEs. These properties were followed through the changes introduced by different stages of elemental chlorine-free (ECF) bleaching, by studying separated VEs. Microprobe X-ray photoelectron spectroscopy (μ-XPS) and field emission-scanning electron microscopy (FE-SEM) were applied to elucidate the surface chemical composition and morphological ultrastructure, respectively. The bulk chemical composition was investigated among others by Py-GC/MS. Lignin was detected in vessels still after completed bleaching sequence, whereas the fibres were lignin-free. The vessel lignin was mainly composed by syringyl-type units. Surface coverage by lignin and amount of surface anionic groups were practically unaffected by bleaching. The vessel cell wall structure was observed to be layered in a complex way with no particular orientation of cellulose fibrils, and the different layers seemed to be exfoliated during different bleaching stages.

Improved Resilience by Formation of Elastomers inside Cotton Fibers

1969 ◽  
Vol 39 (6) ◽  
pp. 560-567 ◽  
Author(s):  
D. Meimoun ◽  
A. Parisot
Keyword(s):  
Mechanical Properties ◽  
Elastic Recovery ◽  
Cotton Fabrics ◽  
Cotton Fibers ◽  
Reaction Parameters ◽  
Permanent Set ◽  
First Results ◽  
Cellulose Fibrils ◽  
Optimum Reaction

The introduction of elastomeric substances between the cellulose fibrils and/or histological elements of cotton fibers could lead to wrinkle-resistant cottons. Such substances, polyenes obtained by polymerization in situ after inclusion within the structure, are unable to penetrate the intermolecular structure, but are able to link together the elements of the fiber. This might result in a fiber with greater delayed elastic recovery and reduced permanent set, permitting wrinkle recovery of cotton fabrics to be increased. The study of optimum reaction parameters resulted in a reproducible process for including the polymer. The location of the polymer has been determined through the development of a new method for revealing the structure of cellulose. The desired mechanical properties of woven treated fabrics are improved, as indicated by various measurements. The first results concerning single fibers seem to corroborate the preceding.

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