title: Electrospinning of agar/PVA aqueous solutions and its relation with rheological properties.
abstract: In this work, we report the successful fabrication of agar-based nanofibers by electrospinning technique, using water as solvent media. A tubeless spinneret was attached inside the electrospinning chamber, operating at 50°C, to avoid agar gelation. Agar pure solution (1 wt%) showed inadequate spinnability regardless of the used electrospinning conditions. The addition of a co-blending polymer such as PVA (10 wt% starting solution) improved the solutions viscoelasticity and hence, the solutions spinnability. Agar/PVA solutions were prepared with different mass ratios (100/0, 50/50, 40/60, 30/70, 20/80 and 0/100) and electrospun at various sets of electrospinning conditions. Best nanofibers were obtained with 30/70 and 20/80 agar/PVA blends while samples with higher agar contents (50/50 and 40/60 agar/PVA) were harder to process and led to discontinuous fibrous mats. This first set of encouraging results can open a new window of opportunities for agar-based biomaterials in the form of nanofibers.
authors.affiliation: REQUIMTE, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; Eastern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, PA 19038, USA.
authors.forename: Ana M M
authors.initials: AM
authors.lastname: Sousa
authors.affiliation: REQUIMTE, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
authors.forename: Hiléia K S
authors.initials: HK
authors.lastname: Souza
authors.affiliation: Eastern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, PA 19038, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Uknalis
authors.affiliation: Eastern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, PA 19038, USA; School of Health Diet and Industry Management, Chung Shan Medical University and Department of Nutrition, Chung Shan Medical University Hospital, 110, Section 1, Jian-Guo North Road, Taichung 402, Taiwan, ROC.
authors.forename: Shih-Chuan
authors.initials: SC
authors.lastname: Liu
authors.affiliation: REQUIMTE, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
authors.forename: Maria P
authors.initials: MP
authors.lastname: Gonçalves
authors.affiliation: Eastern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, PA 19038, USA. Electronic address: LinShu.liu@ars.usda.gov.
authors.forename: LinShu
authors.initials: L
authors.lastname: Liu
mesh_terms: D000362:Agar / Q000737:chemistry*; D004560:Electricity; D057139:Nanofibers / Q000737:chemistry; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D012212:Rheology; D012996:Solutions; D014867:Water / Q000737:chemistry*
chemical_list: D012996:Solutions; D014867:Water; D000362:Agar; D011142:Polyvinyl Alcohol
keywords: Agar; Electrospinning; Nanofibers; PVA; Rheology; Tubeless spinneret