Table 1 Water permeance, rejection of selected salts, MWCO, and pore size distribution for different NF membranes.

From: Polyamide nanofiltration membrane with highly uniform sub-nanometre pores for sub-1 Å precision separation

Type*

Water permeance

Rejection (%)

MWCO

<rp>

σP

(L m−2 h−1 bar−1)

Na2SO4

MgSO4

MgCl2

CaCl2

NaCl

(Da)

(nm)

PIP (2.5% w v−1) with TMC

None⊥

12.6 ± 0.7

97.1 ± 0.5

95.3 ± 0.6

45.5 ± 0.8

24.7 ± 0.6

15 ± 1.1

274

0.334

1.219

SDS

17.1 ± 0.7

99.6 ± 0.9

98.2 ± 0.6

95.0 ± 0.6

93.0 ± 0.8

27.0 ± 0.7

208

0.31

1.177

SDBS

14.9 ± 0.8

98.8 ± 0.8

97.4 ± 0.7

82.0 ± 1.4

77.0 ± 1.1

21.3 ± 1.6

224

0.309

1.208

SB3-14

20.3 ± 0.9

99.1 ± 0.2

98.3 ± 0.8

89.6 ± 0.6

77.9 ± 0.3

20.9 ± 2.5

220

0.313

1.189

CTAB

26.2 ± 0.7

98.1 ± 0.3

90.9 ± 0.2

66.0 ± 1.3

32.0 ± 0.6

9.9 ± 0.7

302

0.362

1.194

TsNA#

14.9 ± 0.8

98.0 ± 0.2

95.4 ± 0.9

50.0 ± 1.2

29.2 ± 0.9

14.8 ± 1.0

255

0.326

1.212

PEI (2.5% w v−1) with TMC

None

28.3 ± 0.9

39.7 ± 2.2

73.2 ± 2.6

88.6 ± 0.6

82.8 ± 1.3

30.7 ± 1.3

449

0.341

1.345

SDS

38.2 ± 0.9

62.5 ± 2.7

93.1 ± 3.1

95.8 ± 0.8

94.1 ± 0.9

46.1 ± 1.6

203

0.291

1.217

  1. Definitions: MWCO molecular weight cutoff, determined using rejection curve of neutral solutes as in Fig. 2b, <rp> mean pore size, σp geometric standard deviation.
  2. ⊥No additive is added. This membrane serves as the baseline.
  3. *Multiple concentrations have been tested for each additive (Supplementary Information) and the best performing results are reported here.
  4. #All other additives are surfactants except for this case (sodium p-toluene sulfonate, or TsNA).
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