Effect of Molecular Weight on Morphological Structure of Electrospun PVA Nanofibre

2015 ◽  
Vol 1134 ◽  
pp. 203-208
Author(s):  
Nur Athirah Abdullah@Shukry ◽  
Khairunnadim Ahmad Sekak ◽  
Mohd Rozi Ahmad
Keyword(s):  
Molecular Weight ◽  
Polyvinyl Alcohol ◽  
Feed Rate ◽  
Fibre Diameter ◽  
Morphological Structure ◽  
Electrospinning Process ◽  
Molecular Weights ◽  
Microscopy Technique ◽  
Average Fibre Diameter ◽  
Average Fibre

This work focuses on the preparation of electrospun Polyvinyl Alcohol (PVA) nanofibres of three different molecular weights. The electrospinning process parameters were varied in terms of the voltage and feed rate. Scanning Electron Microscopy technique was used to characterize the morphological structure of the electrospun PVA nanofibre. The results show that the average fibre diameter increased as the molecular weight of the polymer increased. The formation of beads occurs from the lowest molecular weight sample of 89K However, long, continuous and beaded-free fibres were obtained from the 125K and 205K polymer weight PVA. The results also suggest that higher spinning voltage and feed rate produce larger fibre diameter, respectively.Keywords : Polyvinyl Alcohol, nanofibres, molecular weight, electrospinningCorresponding Author:Khairunnadim Ahmad Sekak, Faculty of Applied Sciences, Universiti Teknologi MARA (UiTM), Shah Alam, 40450 Selangor Darul Ehsan.Email: [email protected]

scholarly journals Experimental Validation of Upward Electrospinning Process

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Faissal Abdel-Hady ◽  
Abdulrahim Alzahrany ◽  
Mostafa Hamed
Keyword(s):  
Gravitational Force ◽  
Vacuum Chamber ◽  
Fibre Diameter ◽  
Solution Concentration ◽  
Electrospinning Process ◽  
Needle Size ◽  
Average Fibre Diameter ◽  
Jet Stability ◽  
Average Fibre

An experimental investigation has been carried out to validate the concept of a new upward electrospinning process in producing polymer nanofibres. The role of gravitational force in this concept is reversed from the conventional downward electrospinning. This inversion results in more stretching of the fibre, less bead formation, and jet stability. An experimental setup is built inside a vacuum chamber in order to eliminate the ambient effects. The effect of various parameters such as applied voltage, needle-collector distance, solution concentration, flow rate, and needle size, on average fibre diameter and beads formation, was investigated using scanning electron microscopy (SEM).

Some wool characteristics of Karadi sheep in northern Iraq

1974 ◽  
Vol 83 (1) ◽  
pp. 171-174 ◽  
Author(s):  
K. E. Ghoneim ◽  
N. T. Kazzal ◽  
R. Kh. Abdallah
Keyword(s):  
Fibre Diameter ◽  
Fibre Length ◽  
Fibre Strength ◽  
Northern Iraq ◽  
Phenotypic Correlations ◽  
Average Fibre Diameter ◽  
Average Fibre

SUMMARYOne hundred and sixty-eight wool samples were collected from commercial flocks of Karadi sheep raised in the five provinces of northern Iraq. The wool characteristics dealt with were staple and fibre length, crimps, fibre diameter, medullation, fibre strength and elongation.The results showed that the Karadi wool is a long type of carpet fleece with average staple and fibre lengths of 19·3 and 23·5 cm, respectively. It had an average fibre diameter of 48·1 μ and contained 19·45 % medullated fibres. The number of crimps per 2 cm was 2·4. Average fibre strength and elongation were 24·8 g/5 cm and 31·8 % respectively. Phenotypic correlations between wool traits were studied.

Studies on Western Australian Merino sheep. 1. Stud, strain and environmental effects on hogget performance

1992 ◽  
Vol 43 (6) ◽  
pp. 1381 ◽  
Author(s):  
RP Lewer ◽  
RR Woolaston ◽  
RR Howe
Keyword(s):  
Fibre Diameter ◽  
Strain Differences ◽  
Average Fibre Diameter ◽  
Weaning Age ◽  
Average Fibre ◽  
Males And Females ◽  
Wool Yield ◽  
Fleece Weight ◽  
Western Australian ◽  
Australian Merino

A 6 year study is reported of Merino studs and strains (Peppin, Collinsville and Bungaree) in Western Australia. Wool and body traits of males and females were measured, with additional subjective traits assessed on females. The effects of strain, stud (within strain), birth year, dam age, birth rearing rank, weaning age and their interactions were estimated using least squares procedures. When tested against studs, strain differences were significant for fibre diameter (both sexes), clean wool yield and about half of the subjective traits (females) but for none of the liveweights. Stud and year effects were significant for all traits, as was their interaction for most traits. Some studs were more stable between years than others in both clean fleece weight and average fibre diameter. Of the remaining effects, birth rearing rank influenced the greatest number of traits, while dam age only affected yield in ewes and some early liveweights. Peppins produced wool 2.0-2.3 microns finer than Bungarees, but not significantly different from Collinsvilles. Peppins also had the best subjective wool scores, but had the highest wrinkle scores and scored poorly on other subjective body traits. Twin-born hoggets produced 0.05-0.15 kg less clean wool than their single-born contemporaries, and their fleeces were about 0.4 microns coarser with poorer subjective qualities. Twins were also lighter from birth (by 23%) up to 17 months (by 5%) in females. Late-born lambs had higher birth weights, but lower subsequent weights, persisting until 12 months in females.

scholarly journals Chromosomal segments underlying quantitative trait loci for mohair production in Angora goats

2009 ◽  
Vol 45 ◽  
pp. 107-112 ◽  
Author(s):  
E.M. Cano ◽  
S. Debenedetti ◽  
M. Abad ◽  
D. Allain ◽  
H.R. Taddeo ◽  
...  
Keyword(s):  
Molecular Markers ◽  
Quantitative Trait Loci ◽  
Quantitative Trait ◽  
Fibre Diameter ◽  
Average Fibre Diameter ◽  
A Genome ◽  
Argentinean Patagonia ◽  
Trait Loci ◽  
Average Fibre ◽  
Angora Goats

SummaryThis study reports the results obtained in the search of chromosomal regions affecting fleece traits in a population of Angora goats in the Argentinean Patagonia. Six hundred thirty-four offspring from 14 parental half-sib families were used. Nine phenotypic fleece traits were recorded at 4 and 11 months of age. A genome examination using 85 informative molecular markers was conducted. A linkage analysis was performed using a regression interval analysis. Our study identified 10 genomic regions affecting the average fibre diameter, coefficient of variation of the average fibre diameter, percentage of fibres with diameters over 30 µm, greasy fleece weight, staple length, average curvature of fibres, percentage of continuous medullated fibres and percentage of kemp fibres located on five goat chromosomes (1, 2, 5, 13 and 19). These results show that the average size of the quantitative trait loci effect was 1.6 phenotypic standard deviations for different traits and families. The aims of quantitative trait loci detection is the potential use of these molecular markers to increase accuracy in predicting the genetic merit of breeding and its implementation in animal breeding schemes through marker-assisted selection.

The use of thyroxine to reduce average fibre diameter in fleece wool when feed intake is increased

2001 ◽  
Vol 41 (5) ◽  
pp. 611 ◽  
Author(s):  
G. J. Lee ◽  
K. J. Thornberry ◽  
A. J. Williams
Keyword(s):  
Saline Solution ◽  
Daily Intake ◽  
Fibre Diameter ◽  
Fibre Length ◽  
Treatment Groups ◽  
Average Fibre Diameter ◽  
Wool Growth ◽  
Average Fibre ◽  
Ad Libitum ◽  
The Difference

An experiment was conducted to determine whether thyroxine injections would control the increases in fibre diameter when the wool growth of Merino wethers is stimulated by an increased supply of feed. Fifty-seven sheep were allocated to 1 of 5 levels of daily intake, ranging from 0.75 maintenance to ad libitum, and injected every third day with 3 mg of L-thyroxine or a saline solution (control). Sheep treated with thyroxine had elevated plasma tri-iodothyronine (T3) levels, which were highest in sheep fed the least (P<0.01). Ad libitum intakes of sheep treated with thyroxine tended to be higher than that of control sheep, particularly in the fifth to seventh weeks of the experiment, and liveweight gain over the initial 4 weeks was significantly (P<0.001) less. Wool growth was increased by thyroxine treatment, although the difference was small in the second half of the experiment at the highest intake levels. Fibre diameter of sheep treated with thyroxine was greater at low intakes, although the difference diminished as intake increased. Fibre length in the second half of the experiment was positively related to intake, but there were no effects of thyroxine. Although the relationships of fibre diameter and length with wool growth did not differ between the treatment groups, length accounted for more of the variation in wool growth in the second half of the experiment in treated wethers than in control wethers (0.376 v. 0.182 of the variation, respectively). Thyroxine did not appreciably reduce the extent of the increase in fibre diameter associated with an increase in the availability and intake of feed.

The effects of breed, crossbreeding and other factors on variation in fleece and skin traits

1980 ◽  
Vol 30 (3) ◽  
pp. 417-429 ◽  
Author(s):  
J. A. Woolliams ◽  
G. Wiener
Keyword(s):  
Unit Area ◽  
Fibre Diameter ◽  
Fibre Length ◽  
Live Weight ◽  
Strong Relationship ◽  
Average Fibre Diameter ◽  
Wide Range ◽  
Average Fibre ◽  
Fleece Weight ◽  
The Relationship

ABSTRACTBreed and crossbreeding significantly affected variation in 10 fleece, follicle density and fibre diameter traits in 12-week-old lambs. The breeds involved were the Scottish Blackface, South Country Cheviot, Welsh Mountain, Lincoln Longwool, Southdown and Tasmanian Merino, but the last only by rams.The Southdown came closest to the Merino in affecting density and diameter traits although the Merino crosses remained clearly distinguishable by their high follicle density. The Lincoln and Blackface crosses were notable for their long fibres and the Blackface crosses also had the least dense follicle and coarsest primary fibres. The coarsest secondary fibres were from Lincoln and Cheviot crosses. Heterosis estimates were obtained for crosses involving the Blackface, Cheviot, Welsh and Lincoln breeds. Significant heterosis was present in a wide range of traits but was not apparent in all crosses. Maternal differences were evident for many of the traits but with density these differences were apparently related to maternal effects on live weight of the lamb. The sex of the lamb, its birth type and rearing and its 12-week live weight significantly affected many of the traits.Among breeds and crosses a strong relationship was found between fibre density and average fibre diameter. The relationship suggested that breed variation in total fibre area per unit area of skin was small compared with the breed variation in its components. Fleece weight per unit area was most closely related to mean fibre length.

Wool yield and characteristics of Dorset, Leicester and Sunffolk breeds and their ‘DLS’ cross

1977 ◽  
Vol 88 (3) ◽  
pp. 651-653 ◽  
Author(s):  
M. H. Fahmy ◽  
J. A. Vasely
Keyword(s):  
First Generation ◽  
Fibre Diameter ◽  
Fibre Length ◽  
Wool Production ◽  
Average Fibre Diameter ◽  
Average Fibre ◽  
Wool Yield ◽  
Fleece Weight

SUMMARYGreasy fleece weight (12 months growth) and wool samples from hip and shoulder regions were taken on 15 Dorset, 20 Leicester, 20 Suffolk and 17 DLS ewes (a cross of ½ Dorset, ¼ Leicester, ¼ Suffolk obtained by mating DL rams to DS ewes and DS rams to DL ewes). The purpose of the study was to compare wool production and characteristics of the first generation of DLS with that of the three breeds of origin. Wool production of DLS was 3·58 kg, 8·8 and 14% higher than that of Suffolk and Dorset, but 11% lower than that of Leicester (P< 0·01). The percentage of clean wool was highest in Leicester (78·3%), followed by DLS, Dorset and Suffolk (76·1, 74·3 and 70·5%, respectively). The average fibre diameter of the DLS and Leicester was 38 /m, 4 /m thicker than that for Suffolk and Dorset (P < 0·01). Average fibre length was 15 cm in DLS and Dorset, 6 cm shorter than in Leicester, and 3 cm longer than in Suffolk (P < 0·01). The variability in fibre diameter and length was highest in Leicester, followed closely by DLS.

scholarly journals Fabrication and Characterisation of Titanium Dioxide (Tio2)/PVA Nanofibre Composites using Electrospinning

2019 ◽  
Vol 7 (4.14) ◽  
pp. 348
Author(s):  
N. D.N. Affandi ◽  
L. Y. Chin ◽  
F. Fadil ◽  
F. A. Azhar
Keyword(s):  
Titanium Dioxide ◽  
Polyvinyl Alcohol ◽  
Research Work ◽  
Fibre Diameter ◽  
Control Sample ◽  
Morphological Structure ◽  
Nano Particles ◽  
Membrane Area ◽  
Membrane Surfaces ◽  
Pva Solutions

A study on the formation of titanium dioxide (TiO2)/ polyvinyl alcohol (PVA) nanofibres has been investigated in the research work. In the study, the TiO2/PVA solutions were prepared at different concentrations ranging from 1wt% to 10wt%. The PVA solution without TiO2 was used as control sample in the study. Each solution was extruded using electrospinning at different voltages to form long and continuous nanofibres. The fibres were then characterised for morphological structures, fibre diameter and membrane area. The result shows that control sample of PVA nanofibres formed beads on the fibre surfaces. The addition of TiO2 in PVA was found to reduce the bead formation. The clumps of TiO2 nanoparticles were observed and were also confirmed with the EDX mapping. In addition, the electrospinning parameters affect the formation of TiO2/PVA nanofibers. At 15 kV, the resultant fibre diameter increases from 153 ± 23 nm to 191 ± 26 nm when the TiO2 concentration was further increased from 1wt% to 10wt%. The morphological structure of TiO2/PVA nanofibres varies depending on applied voltages and concentrations used. The membrane area of TiO2/PVA nanofibers is approximately 187 cm2 for 1wt% of TiO2. From the study, it shows that an optimalconcentration to produce TiO2/ PVA nanofibers is 10wt%. At 10wt%, no beads were observed on the fibre and the TiO2 nano-particles were uniformly distributed on the membrane surfaces.  

Influence of Multiwall Carbon Nanotube on Polyethersulfone/ Polyvinyl Alcohol Blend Membranes

2014 ◽  
Vol 67 (2) ◽  
Author(s):  
Nur Farahah Mohd Khairuddin ◽  
Ani Idris ◽  
Iqbal Ahmed ◽  
Noordin Mohd Yusof
Keyword(s):  
Molecular Weight ◽  
Contact Angle ◽  
Carbon Nanotube ◽  
Polyvinyl Alcohol ◽  
Water Flux ◽  
Multiwall Carbon Nanotube ◽  
Flux Rate ◽  
Molecular Weights ◽  
Blend Membranes ◽  
Multiwall Carbon

This paper investigates the influence of multiwall carbon nanotube (MWCNT) on the morphology and properties of polyethersulfone (PES) and polyvinyl alcohol (PVA) blend membranes. Several membranes were prepared by blending 0.5 wt% MWCNT , 18%wt PES and 1.5wt% PVA of various molecular weights (60, 145 and 200 kDa) in  dimethyl acetate (DMAC) solvent. The membranes were then evaluated in terms of its morphology, contact angle, water flux rate and porosity. The results revealed that MWCNT nanoparticles have decreased the contact angle and increased the flux rate of PES/PVA blend membranes. The presence of MWCNT in the PES/PVA membranes have promoted the formation of fingerlike pores in the membranes structure and thus increased the porosity of the membranes. Besides that, the use of higher molecular weight PVA helped to reduce the contact angle of the membranes reflecting to their hydrophilic nature. However, the use of lower molecular weight PVA was found to enhance the increased of flux rate and porosity of the membrane.

Fleece growth in Australian cashmere goats. 1. The effects of nutrition and age on fleece growth, prolactin and thyroxine concentration

1993 ◽  
Vol 44 (5) ◽  
pp. 1003 ◽  
Author(s):  
WRL Kloren ◽  
BW Norton ◽  
MJ Waters
Keyword(s):  
Composition Studies ◽  
Hormone Secretion ◽  
Plasma Concentrations ◽  
Age Groups ◽  
Fibre Diameter ◽  
Feeding Level ◽  
Average Fibre Diameter ◽  
Average Fibre ◽  
Cashmere Goats ◽  
Effect Of Feeding

Australian cashmere goats were studied from January to July to assess the effects of increasing feeding level (maintenance, M: 42 g D M / W0.75/day, 1.4 M, 1.8 M and 2.3 M (ad libitum)) and age (Young, 6 months; Old 18 months) on fleece growth, and plasma concentrations of prolactin (Prl) and thyroxine (T4). Comparisons of fleece composition (weight, cashmere fibre diameter, proportion of cashmere) were made from fleece shorn monthly (left side) and at the end of the experiment (right side). There was no significant (P > 0.05) effect of feeding level or age on cashmere weight (39.8 g), cashmere diameter (15.3 8m) or hair weight (224.7 g) at shearing in July. Similar results were observed with monthly fleece composition studies, although cumulative cashmere weight for Young goats (27.1 g) was significantly (P <0.05) less than that of Old goats (48.5 g), and average fibre diameter of cashmere of Young goats (13.6 8m) was less than that of Old goats (15.6 8m). Serum Prl concentration in groups on higher feeding levels (1.8 M, 2.3 M) increased significantly (P < 0.05) over the duration of the study (45 to 70 ng/mL and 15 to 70 ng/mL for 1.8 M and 2.3 M respectively), whilst that of the groups on lower feeding levels (M, 1.4 M) remained low (15 ng/mL). The results are discussed in relation to the seasonal change in fleece composition and hormone secretion for the different feeding levels and age groups, and a possible antagonism between Prl secretion and fleece growth.

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