Browsing by Author "Zhang, Yongchao"
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- Robust shape-retaining nanocellulose-based aerogels decorated with silver nanoparticles for fast continuous catalytic discoloration of organic dyes
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2020-07-01) Zhang, Weihua; Wang, Xiaoju; Zhang, Yongchao; van Bochove, Bas; Mäkilä, Ermei M.; Seppälä, Jukka; Xu, Wenyang; Willför, Stefan; Xu, ChunlinIn this work we present a green method to prepare aerogel membranes based on cellulose nanofibers (CNFs) crossed-linked with poly (ethylene imine) (PEI) and further decorated with silver nanoparticles (Ag NPs). The nanosized Ag NPs were reduced and immobilized on the surface of the pore walls inside the aerogel. The as-prepared composite aerogel membrane showed excellent continuous catalytic discoloration of aqueous cationic and anionic dye solutions in batch and flow filtration tests. Moreover, the aerogel membrane exhibited very stable catalytic activity with discoloration efficiency at as high as 98% after 10 times reuse and the water permeance was high, up to 5 × 10 4 L·m −2 h −1. Interestingly, the aerogel membrane showed excellent shape recovery in water and no obvious deterioration of the structure was observed during long time testing. Therefore, the obtained aerogel membranes showed great potential in waste water treatment and catalytic applications. - Surface Engineered Biomimetic Inks Based on UV Cross-Linkable Wood Biopolymers for 3D Printing
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä(2019-04-03) Xu, Wenyang; Zhang, Xue; Yang, Peiru; Långvik, Otto; Wang, Xiaoju; Zhang, Yongchao; Cheng, Fang; Österberg, Monika; Willför, Stefan; Xu, ChunlinOwing to their superior mechanical strength and structure similarity to the extracellular matrix, nanocelluloses as a class of emerging biomaterials have attracted great attention in three-dimensional (3D) bioprinting to fabricate various tissue mimics. Yet, when printing complex geometries, the desired ink performance in terms of shape fidelity and object resolution demands a wide catalogue of tunability on the material property. This paper describes surface engineered biomimetic inks based on cellulose nanofibrils (CNFs) and cross-linkable hemicellulose derivatives for UV-aided extrusion printing, being inspired by the biomimetic aspect of intrinsic affinity of heteropolysaccharides to cellulose in providing the ultrastrong but flexible plant cell wall structure. A facile aqueous-based approach was established for the synthesis of a series of UV cross-linkable galactoglucomannan methacrylates (GGMMAs) with tunable substitution degrees. The rapid gelation window of the formulated inks facilitates the utilization of these wood-based biopolymers as the feeding ink for extrusion-based 3D printing. Most importantly, a wide and tunable spectrum ranging from 2.5 to 22.5 kPa of different hydrogels with different mechanical properties could be achieved by varying the substitution degree in GGMMA and the compositional ratio between GGMMA and CNFs. Used as the seeding matrices in the cultures of human dermal fibroblasts and pancreatic tumor cells, the scaffolds printed with the CNF/GGMMA inks showed great cytocompatibility as well as supported the matrix adhesion and proliferative behaviors of the studied cell lines. As a new family of 3D printing feedstock materials, the CNF/GGMMA ink will broaden the map of bioinks, which potentially meets the requirements for a variety of in vitro cell-matrix and cell-cell interaction studies in the context of tissue engineering, cancer cell research, and high-throughput drug screening.