title: Understanding shape and morphology of unusual tubular starch nanocrystals.
abstract: Starch nanocrystals (SNC) are aptly described as the insoluble degradation byproducts of starch granules that purportedly display morphologies that are platelet-like, round, square, and oval-like. In this work, we reported the preparation of SNC with unprecedented tubular structures through sulfuric acid hydrolysis of normal maize starch, subsequent exposure to ammonia and relaxation at 4°C. High-resolution transmission electron microscopy observation clearly proved that the SNCs possess tubular nanostructures with polygonal cross-section. After further reviewing the transformations of SNC by acid hydrolysis, ammonia treatment, and curing time at 4°C, a mechanism for T-SNC formation is suggested. It is conjectured that T-SNC gradually self-assembles by combination of smaller platelet-like/square nanocrystals likely loosely aggregated by starch molecular chains from residual amorphous regions. This work paves the way for the pursuit of new approaches for the preparation of starch-based nanomaterials possessing unique morphologies.
authors.affiliation: Key Laboratory of Pulp & Paper Science and Technology (Ministry of Education), Qilu University of Technology, Jinan, Shandong 250353, PR China.
authors.forename: Bei
authors.initials: B
authors.lastname: Gong
authors.affiliation: Key Laboratory of Pulp & Paper Science and Technology (Ministry of Education), Qilu University of Technology, Jinan, Shandong 250353, PR China. Electronic address: liuwenxia@qlu.edu.cn.
authors.forename: Wenxia
authors.initials: W
authors.lastname: Liu
authors.affiliation: Key Laboratory of Pulp & Paper Science and Technology (Ministry of Education), Qilu University of Technology, Jinan, Shandong 250353, PR China.
authors.forename: Hua
authors.initials: H
authors.lastname: Tan
authors.affiliation: Key Laboratory of Pulp & Paper Science and Technology (Ministry of Education), Qilu University of Technology, Jinan, Shandong 250353, PR China.
authors.forename: Dehai
authors.initials: D
authors.lastname: Yu
authors.affiliation: Key Laboratory of Pulp & Paper Science and Technology (Ministry of Education), Qilu University of Technology, Jinan, Shandong 250353, PR China.
authors.forename: Zhaoping
authors.initials: Z
authors.lastname: Song
authors.affiliation: Key Laboratory of Pulp & Paper Science and Technology (Ministry of Education), Qilu University of Technology, Jinan, Shandong 250353, PR China; North Carolina State University, Departments of Chemistry, Forest Biomaterials, Raleigh, NC 27695, USA. Electronic address: lucian.lucia@163.com.
authors.forename: Lucian A
authors.initials: LA
authors.lastname: Lucia
mesh_terms: D000641:Ammonia / Q000737:chemistry; D006868:Hydrolysis; D053758:Nanoparticles / Q000737:chemistry*; D012972:Sodium Hydroxide / Q000737:chemistry; D013213:Starch / Q000737:chemistry*; D003313:Zea mays / Q000737:chemistry
chemical_list: D012972:Sodium Hydroxide; D000641:Ammonia; D013213:Starch
keywords: Ammonia (PubChem CID: 222); Amylopectin (PubChem CID: 439207); Amylose (PubChem CID: 192826); Chemical transformation; Corn starch (PubChem CID: 439341); Self-assembly; Starch nanocrystals; Sulfuric acid (PubChem CID:1118); Tubular structures; d-Glucose (PubChem CID: 5793); α-d-Glucose (PubChem CID: 79025)