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Electrospinning of Reinforced Starch Fibers.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Electrospinning of Reinforced Starch Fibers./
作者:	Wang, Hui.
出版者:	Ann Arbor : ProQuest Dissertations & Theses, : 2018,
面頁冊數:	161 p.
附註:	Source: Dissertations Abstracts International, Volume: 80-10, Section: B.
Contained By:	Dissertations Abstracts International80-10B.
標題:	Agriculture. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=13871938
ISBN:	9781392040430

Electrospinning of Reinforced Starch Fibers.
Wang, Hui.

Electrospinning of Reinforced Starch Fibers. - Ann Arbor : ProQuest Dissertations & Theses, 2018 - 161 p.

Source: Dissertations Abstracts International, Volume: 80-10, Section: B.

Thesis (Ph.D.)--The Pennsylvania State University, 2018.

Electrospinning is a versatile technique to fabricate non-woven fiber mats with an average fiber diameter ranging from nanometers to micrometers. Fibers produced by electrospinning have potential application in numerous fields owing to their small diameter, light weight, high surface area, and high porosity. Compared to their synthetic counterparts, fibers electrospun from bio-based polymers have the attractive advantages of biodegradability, biocompatibility, and competitive cost, but generally have inferior mechanical strength and are difficult to produce. Therefore, further improvement in their mechanical properties and the electrospinning process are required to utilize them. Starch is one of the most abundant carbohydrate polymers on earth, and has been processed into fibers by wet-electrospinning. Like other biopolymer fibers, starch fiber mats are limited by their inferior mechanical properties. Here different strategies were employed to increase the tensile strength of wet-electrospun starch fiber mats. The effect of post-drying conditioning at controlled equilibrium relative humidity and equilibration time on the tensile property of fiber mats was evaluated. The weight-normalized ultimate tensile strength of starch fiber mats increased significantly with equilibration at relative humidity >0.75 after 28 days. Morphological observation and X-ray diffraction analysis excluded significant changes in fiber size or crystallinity, and thus I concluded that conglutination, observed microscopically, brought about by the plasticizing effect of water was primarily responsible for this mechanical improvement. The mechanical strength of electrospun starch-based fibers was improved by using nanocellulose as a reinforcing filler and cationic starch as a binding agent. The potential ionic bonding between cationic starch and anionic nanocellulose, and the hydrogen bonding as well as macromolecular entanglement between the three components, were expected to improve the compatibility of polymers and the mechanical strength of their composite fibers. Rheological properties of nanocellulose, cationic starch, and their mixtures were studied to understand their conformation and interaction in DMSO dispersions. The rheological properties of the ternary system were studied and correlated with their electrospinnability and tensile strength of the composite fiber mats. The results suggested that nanocellulose-cationic starch at its percolation concentration (≈2%, w/w, of starch) has the most profound influence on fiber strength, and cationic starch:nanocellulose ratios of 1:2 and 1:1 created improved intermolecular ionic bonding for reinforcing the fiber structure. The feasibility of obtaining aligned starch fiber mats in wetelectrospinning was explored and an inexpensive setup for laboratory investigation was designed. The effects of three operational parameters, i.e., rotational speed, drum location, and coagulation bath composition, were evaluated. The alignment of starch fibers was affected by the ethanol concentration in the coagulation bath and drum rotational speed. The tensile strength was correlated with fiber alignment and influenced by the interaction of location and ethanol concentration, and that of rotational speed and ethanol concentration. A green method to fabricate nanofibers from starch using electrospinning was developed. High-temperature (>160 ºC) was used to destructure high-amylose starch to create an aqueous solution. Sodium palmitate was added to enhance the stability of high amylose starch in water at room temperature and increase the conductivity of the electrospinning dope. Pullulan was mixed in as a minor component of the starch-palmitate complex and the mixture electrospun. Pullulan hindered starch association and modified the dispersion properties, promoting molecular entanglement without gelation and decreasing surface tension. Nanoscale fiber composites containing starch:pullulan at a ca. 2:1 ratio were prepared. The presence of sodium palmitate inclusion in the fiber was confirmed by differential scanning calorimetry and X-ray diffraction. The fiber diameter of the nanofiber composite was found to be smaller (146 nm vis-a-vis 2 micrometers) than that of pure starch fiber mats, but the tensile strength was weaker (15 N/g vis a-vis 30 N/g). For the first time, electrospinning starch-based natural polymer blends from aqueous solvent is reported.

ISBN: 9781392040430Subjects--Topical Terms:

518588
Agriculture.
Subjects--Index Terms:

Starch fiber mats

Electrospinning of Reinforced Starch Fibers.
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020 $a 9781392040430
035 $a (MiAaPQ)AAI13871938
035 $a AAI13871938
040 $a MiAaPQ $c MiAaPQ
100 1 $a Wang, Hui. $3 836732
245 1 0 $a Electrospinning of Reinforced Starch Fibers.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2018
300 $a 161 p.
500 $a Source: Dissertations Abstracts International, Volume: 80-10, Section: B.
500 $a Publisher info.: Dissertation/Thesis.
500 $a Advisor: Ziegler, Gregory R.
502 $a Thesis (Ph.D.)--The Pennsylvania State University, 2018.
520 $a Electrospinning is a versatile technique to fabricate non-woven fiber mats with an average fiber diameter ranging from nanometers to micrometers. Fibers produced by electrospinning have potential application in numerous fields owing to their small diameter, light weight, high surface area, and high porosity. Compared to their synthetic counterparts, fibers electrospun from bio-based polymers have the attractive advantages of biodegradability, biocompatibility, and competitive cost, but generally have inferior mechanical strength and are difficult to produce. Therefore, further improvement in their mechanical properties and the electrospinning process are required to utilize them. Starch is one of the most abundant carbohydrate polymers on earth, and has been processed into fibers by wet-electrospinning. Like other biopolymer fibers, starch fiber mats are limited by their inferior mechanical properties. Here different strategies were employed to increase the tensile strength of wet-electrospun starch fiber mats. The effect of post-drying conditioning at controlled equilibrium relative humidity and equilibration time on the tensile property of fiber mats was evaluated. The weight-normalized ultimate tensile strength of starch fiber mats increased significantly with equilibration at relative humidity >0.75 after 28 days. Morphological observation and X-ray diffraction analysis excluded significant changes in fiber size or crystallinity, and thus I concluded that conglutination, observed microscopically, brought about by the plasticizing effect of water was primarily responsible for this mechanical improvement. The mechanical strength of electrospun starch-based fibers was improved by using nanocellulose as a reinforcing filler and cationic starch as a binding agent. The potential ionic bonding between cationic starch and anionic nanocellulose, and the hydrogen bonding as well as macromolecular entanglement between the three components, were expected to improve the compatibility of polymers and the mechanical strength of their composite fibers. Rheological properties of nanocellulose, cationic starch, and their mixtures were studied to understand their conformation and interaction in DMSO dispersions. The rheological properties of the ternary system were studied and correlated with their electrospinnability and tensile strength of the composite fiber mats. The results suggested that nanocellulose-cationic starch at its percolation concentration (≈2%, w/w, of starch) has the most profound influence on fiber strength, and cationic starch:nanocellulose ratios of 1:2 and 1:1 created improved intermolecular ionic bonding for reinforcing the fiber structure. The feasibility of obtaining aligned starch fiber mats in wetelectrospinning was explored and an inexpensive setup for laboratory investigation was designed. The effects of three operational parameters, i.e., rotational speed, drum location, and coagulation bath composition, were evaluated. The alignment of starch fibers was affected by the ethanol concentration in the coagulation bath and drum rotational speed. The tensile strength was correlated with fiber alignment and influenced by the interaction of location and ethanol concentration, and that of rotational speed and ethanol concentration. A green method to fabricate nanofibers from starch using electrospinning was developed. High-temperature (>160 ºC) was used to destructure high-amylose starch to create an aqueous solution. Sodium palmitate was added to enhance the stability of high amylose starch in water at room temperature and increase the conductivity of the electrospinning dope. Pullulan was mixed in as a minor component of the starch-palmitate complex and the mixture electrospun. Pullulan hindered starch association and modified the dispersion properties, promoting molecular entanglement without gelation and decreasing surface tension. Nanoscale fiber composites containing starch:pullulan at a ca. 2:1 ratio were prepared. The presence of sodium palmitate inclusion in the fiber was confirmed by differential scanning calorimetry and X-ray diffraction. The fiber diameter of the nanofiber composite was found to be smaller (146 nm vis-a-vis 2 micrometers) than that of pure starch fiber mats, but the tensile strength was weaker (15 N/g vis a-vis 30 N/g). For the first time, electrospinning starch-based natural polymer blends from aqueous solvent is reported.
590 $a School code: 0176.
650 4 $a Agriculture. $3 518588
650 4 $a Nanotechnology. $3 526235
650 4 $a Materials science. $3 543314
653 $a Starch fiber mats
653 $a Tensile strength
653 $a Wet-electrospinning
690 $a 0473
690 $a 0652
690 $a 0794
710 2 $a The Pennsylvania State University. $b Food Science. $3 3352085
773 0 $t Dissertations Abstracts International $g 80-10B.
790 $a 0176
791 $a Ph.D.
792 $a 2018
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=13871938