Development of porous fabric‐hydrogel composite membranes with enhanced ion permeability for microalgal cultivation in the ocean

Abstract

This article presents a strategy to develop the porous fabric-hydrogel composite membranes (PFHCMs) with high nitrate ion (NO 3 − , a source of a main nutrient, nitrogen) permeability and sufficient mechanical strength required for microalgal cultivation in the ocean. The porous structure in the PFHCMs is generated by using three different types of porogens: water-soluble macromolecules, surfactant micelles, and CaCO 3 microparticles. Various PFHCMs, composed mainly of poly(hydroxyethyl methacrylate) hydrogels and cotton fabric, are prepared with varying the content of monomer, initiator, and crosslinker and the type and content of porogen. Their morphological, physical, and mechanical properties are characterized for variables. Among three porogens, the surfactant micelles with a large enough amount produce the optimal PFHCMs with NO 3 − ion permeability coefficient (5.49 × 10 −8 m 2 min −1 , approximately 5 and 20 times higher than those of the fabric-hydrogel composite membranes, synthesized without any porogen in a previous work, and the commercial cellulose acetate membranes, respectively). Their mechanical strength (i.e., the ultimate stress is 9.37 MPa) is high enough for practical uses. Therefore, these PFHCMs are good candidate membranes in microalgal cultivation for biorefinery and other biomedical applications, including wound dressings.

New Surface Modification Method To Develop a PET-Based Membrane with Enhanced Ion Permeability and Organic Fouling Resistance for Efficient Production of Marine Microalgae

“…Accordingly, the development of effective cultivation technologies for massive and low-cost production of microalgae with unlimited potential for fuel sources and functional foods is needed. Microalgae cultivation in the ocean has been considered as an advantageous and effective method for high biomass production because of the infinite supply of nutrients and sunlight, natural agitation by winds and waves, and small temperature fluctuations. , Moreover, for even higher marine microalgae production, the use of a membrane photobioreactor (MPBR) through which the necessary nutrient ions and water can continuously be transported was first introduced by our research group. , Since then, we have continuously carried out the development of desirable permselective membranes (PSMs) for use as photobioreactors. , The desirable properties of the PSMs for marine microalgae cultivation are high permeability of water and nutrient ions through the membrane, sufficient mechanical strength to withstand harsh conditions in the ocean, and fouling resistance to avoid adhering and blocking of the ion-permeable pores. Additionally, their reasonable price is also an essential requirement for the practical use of such membranes.…”

“…9,10 Since then, we have continuously carried out the development of desirable permselective membranes (PSMs) for use as photobioreactors. 11,12 The desirable properties of the PSMs for marine microalgae cultivation are high permeability of water and nutrient ions through the membrane, sufficient mechanical strength to withstand harsh conditions in the ocean, and fouling resistance to avoid adhering and blocking of the ion- permeable pores. Additionally, their reasonable price is also an essential requirement for the practical use of such membranes.…”

Natural fibers woven fabric reinforced hydrogel composites for enhanced mechanical properties

“…Textile structures such as fabric hydrogel composite membranes which includes cotton fabric [22], glass fabric [23], nano and micro scale fibrous woven fabrics [24] have been combined with hydrogels. In our previous study, as-prepared PVA/cotton fabrics were treated with different concentrations of aqueous borax and glutaraldehyde crosslinking solutions to prepare cotton fabric reinforced hydrogel composite [25].…”

Durability of fiber‐reinforced polyoxymethylene composites under the high hydrostatic pressure in the deep sea

“…At present, fiber‐reinforced polymer composites have been widely used in marine applications due to their lightweight, high specific strength and corrosion resistance . In addition to traditional marine boat and ship structures above seawater, there are immersed systems such as tidal turbines and hydraulic pumps in which composite materials are starting to provide key contributions .…”