1.Publication Points

Shape-persistent and tough cellulose hydrogels were fabricated by a stepwise solvent exchange from a homogeneous ionic liquid solution of cellulose exposure to methanol vapor. The cellulose hydrogels maintain their shapes under changing temperature, pH, and solvents. The micrometer-scale patterns on the mold were precisely transferred onto the surface of cellulose hydrogels. We also succeeded in the spinning of cellulose hydrogel fibers through a dry jet-wet spinning process. The mechanical property of regenerated cellulose fibers improved by the drawing of cellulose hydrogel fibers during the spinning process.

This approach for the fabrication of tough cellulose hydrogels is a major advance in the fabrication of cellulose-based structures with defined shapes. The results of this research are published in "Scientific Reports"*, an online journal from the publishers of Nature.


Figure 1: (a) Optical images of flower-shaped cellulose hydrogels prepared from 5 wt% IL solution of WP. The inset is an optical image of bridged cellulose hydrogel. (b) SEM image of the surface of dried cellulose hydrogel. (c) Schematic gelation process of the cellulose solution.


Figure 2: Stress-strain curve for 5 wt% WP cellulose hydrogel (water-content: 95 wt%) under uniaxial compression. The inset is the stress-strain curves of 1 wt% WP hydrogel (solid line; water-content: 99 wt%) and 5 wt% MCC hydrogel (dashed line; water-content: 95 wt%).

2.Background behind the results

The results of this research form part of the research initiatives of Shinshu University and other institution that seek to establish innovative desalination and water reclamation systems in line with the vision "establish a sustainable society with vitality". Shinshu University is the core hub for the project "Global Aqua Innovation Center for Improving Living Standard and Water-sustainability**," funded by Japan Science and Technology Agency (JST)'s Center of Innovation (COI) Program.

As part of efforts to resolve global water shortages, the project team has been focusing on three key water resources, all of which contain salt: seawater, produced water and blackish water. We are involved in the research and development of reverse osmosis (RO) membranes that use nanocarbons instead of conventional polyamide, which is our key technology for desalination.

*Scientific Reports
Mutsumi Kimura, Yoshie Shinohara, Junko Takizawa, Sixiao Ren, Kento Sagisaka, Yudeng Lin, Yoshiyuki Hattori, Juan P. Hinestroza, "Versatile Molding Process for Tough Cellulose Hydrogel Materials", Scientific Reports. DOI:10.1038/srep16266

**Center of Innovation (COI) Program
This is an open recruitment type R&D program operated by the Japan Science and Technology Agency (JST). Here, the premise is based on the vision to anticipate the structure and lifestyle of society that should be aimed for considering the needs of future society that are dormant at present --- however, as this requires groundbreaking innovation that companies alone cannot hope to achieve, the initiative has been taken to tackle R&D via an industry-academia collaboration.
Shinshu University is the core institution of the "Aqua Innovation Center for Improving Living Standards and Water-sustainability" within Vision 3 Establish a sustainable society with vitality (Visionaly leader: Masaharu Sumikawa, Hitachi, Ltd., Executive Adviser).

- Project leader (PL): Shinjiro Ueda (Hitachi Infrastructure Systems Company, Executive Technology Adviser)
- Research leader (RL): Morinobu Endo (Shinshu University, Distinguished Professor)

■ Core institutions
Shinshu University
■ Core companies
Hitachi Infrastructure Systems Company, Toray Industries, Inc. and Showa Denko K.K.
■ Paticipants
National Institute for Materials Science, RIKEN, Research Organization for Information Science and Technology, Kitagawa Industries Co., Ltd. Toclas Corporation, and Nagano prefecture
■ COI-S satellite
Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Sony Computer Science Laboratories, University of Tokyo, Chuo University and Japan Aerospace Exploration Agency (JAXA)

- R&D period: FY2013 to FY2021 (maximum duration)