UiO-66-NH₂ nanocomposites incorporated cellulose acetate for forward osmosis membranes of high desalination performance

ABSTRACT

In this paper, the hydrophilic UiO-66-NH₂ nanomaterial was synthesized by the solvent-thermal method and characterized. Then, UiO-66-NH₂ was introduced into the casting membrane solution of cellulose acetate (CA) forward osmosis (FO) membrane, and CA/UiO-66-NH₂ forward osmosis membrane was prepared by the phase inversion method. The optimum preparation conditions of CA/UiO-66-NH₂ mixed matrix membranes were determined as follows: the content of UiO-66-NH₂ was 0.4 wt%, the coagulation bath temperature was 35°C, the mixing temperature was 50°C and the heat treatment temperature was 50°C. FTIR, SEM, water contact angle and AFM were carried out on CA/UiO-66-NH₂ forward osmosis membrane prepared under the best preparation conditions. Compared to the CA forward osmosis membrane, the permeability and selectivity of the CA/UiO-66-NH₂ membrane were improved. The water flux and reverse salt flux of the CA/UiO-66-NH₂ forward osmosis membrane reached 52.32 L/(m²·h) and 2.43 g/(m²·h), respectively. The permeability selectivity of CA membranes and CA/UiO-66-NH₂ membranes did not change much during 180 min, indicating that the two membranes had good long-term stability. This study shows a potential advantage of UiO-66-NH₂ as additives for improvement in the desalination performance of forward osmosis membranes.

GRAPHICAL ABSTRACT

KEYWORDS:

• Cellulose acetate
• desalination
• FO
• mixed matrix membrane
• UiO-66-NH₂

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 21777055]; Natural Science Foundation of Shandong Province [grant numbers ZR2018LB026, ZR2020MB120, and ZR2021MB063]; Shandong Province Key Research and Development Plan [grant numbers 2018GGX102032 and 2019GSF109116]; Project of Shandong Province Higher Educational Science and Technology Program [grant number 2018LS007]; Shandong Key Laboratory of Water Pollution Control and Resource Reuse [grant number 2019KF09].