Symbols
D	Diffusion coefficient (m2 s−1)
pKa	Acid dissociation constant (-)
P	Permeability coefficient (Barrer)
S	Solubility coefficient (cm3STP cm−3 bar−1)
Vw	Van der Waals volume (cm3 mol−1)
α	Permselectivity (-)
Miscellaneous Abbreviations
AFM	Atomic force microscopy
AIBN	2,2-azobisisobutyronitrile
ATRP	Atom transfer radical polymerization
BET	Brunauer-Emmett-Teller
C-G	Chain growth polymerization
CHI	Chitosan
COSMO	Conductor-like screening model
DMPA	2,2-dimethoxy-2-phenylacetophenone
EDX	Energy dispersive X-ray analysis
FRP	Free radical polymerization
GPU	Gas permeation unit or Gas permeance unit
HA	Hyaluronic acid or Sodium hyaluronate
IL	Ionic liquid
ILM	Ionic liquid membranes
LMOG	Low molecular-weight organic gelators
MBAA	N,N′-methylenebis(acrylamide)
MOF	Metalorganic framework
MPa	Mega pascal
PIL	Polymerized ionic liquid or Poly(ionic liquid)
PIM	Polymer of intrinsic microporosity
RAFT	Reversible addition-fragmentation chain transfer
RH	Relative humidity
ROMP	Ring-opening metathesis polymerization
RTIL	Room-temperature ionic liquids
SCFD	Supercritical fluid deposition
SD	Solution-diffusion
SEM	Scanning electron microscopy
S-G	Step growth polymerization
SILM	Supported ionic liquid membrane
TGA	Thermogravimetric analysis
UV	Ultra-violet radiation
VOC	Volatile organic compound
XDC	p-Xylylene dichloride
XPS	X-ray photoelectron spectroscopy
Ionic Liquids
[(SiOSi)C1MIM][C(CN)3]	1-Methyl-3-pentamethyldisiloxymethylimidazolium Tricyanomethanide
[(SiOSi)C1MIM][Tf2N]	1-Methyl-3-pentamethyldisiloxymethylimidazolium Bis(trifluoromethylsulfonyl)imide
[APTMS][Ac]	(3-Aminopropyl)-trimethoxysilane Acetate
[BMIM][Ac]	1-Butyl-3-methylimidazolium Acetate
[BMIM][BF4]	1-Butyl-3-methylimidazolium Tetrafluoroborate
[BMIM][DCA]	1-butyl-3-methylimidazolium Dicyanamide
[BMIM][Doc]	1-Butyl-3-methylimidazolium bis(2-ethylhexyl)sulfosuccinate
[BMIM][Pho]	1-Butyl-3-methylimidazolium Phenolate
[BMIM][Tf2N]	1-butyl-3-methylimidazolium Bis(trifluoromethylsulfonyl)imide
[BMIM][TfO]	1-butyl-3-methylimidazolium Trifluoromethane sulfonate
[C1C3MIM][Tf2N]	1-methyl-3-propylmethylimidazolium Bis(trifluoromethylsulfonyl)imide
[C3C1MIM][Tf2N]	1-propyl-3-methylimidazolium Bis(trifluoromethylsulfonyl)imide
[Choline][Gly]	Cholinium Glycolate
[Choline][Lac]	Cholinium L(+) lactate
[Choline][Lev]	Cholinium Levulinate
[Choline][Mal]	Cholinium Malonate
[Choline][Pro]	Cholinium Proline
[DMAPAH][EtOAc]	3-(Dimethylamino)-1-propylammonium Ethoxyacetate
[DMAPAH][TfA]	3-Dimethylamino-1-propylammonium Trifluoroacetate
[EMIM][Ac]	1-Ethyl-3-methylimidazolium Acetate
[EMIM][C(CN)3]	1-Ethyl-3-methylimidazolium Tricyanomethanide
[EMIM][ESU]	1-Ethyl-3-methylimidazolium Ethyl sulfate
[EMIM][Et2PO4]	1-Ethyl-3-methylimidazolium Diethylphosphate
[EMIM][FAP]	1-Ethyl-3-methylimidazolium Trifluoro phosphate
[EMIM][FAP]	1-Ethyl-3-methylimidazolium Trifluoro phosphate
[EMIM][Me2PO4]	1-Ethyl-3-methylimidazolium Trimethylphosphate
[EMIM][Tf2N]	1-Ethyl-3-methylimidazolium Bis(trifluoromethylsulfonyl)imide
[EMIM][TfA]	1-Ethyl-3-methylimidazolium Trifluoroacetate
[HMIM][Tf2N]	1-Hexyl-3-methylimidazolium Bis(trifluoromethylsulfonyl)imide
[HmMIM][Tf2N]	1-Hexyl-2-methyl-3-methylimidazolium Bis(trifluoromethylsulfonyl)imide
[OMIM][Ac]	1-Octyl-3-methylimidazolium Acetate
[P222(101)][Inda]	Triethyl(2-methoxymethyl) phosphonium Indazolide
[P2225][Pro]	Triethyl(pentyl)phosphonium Prolinate
[P4444][Pro]	Tetrabutylphosphonium Prolinate
[Si-C1-C3-MIM][Tf2N]	1-Methyl-3-(2-methyl-3-(trimethylsilyl)propyl)imidazolium Bis(trifluoromethylsulfonyl)imide
[VBTMA[Ac]	Vinylbenzyl trimethylammonium Acetate
[VOIM][PF6]	1-vinyl-3-octylimidazolium Hexafluorophosphate
Cations
P	Phosphonium
R1R2Mor	Morpholinium cation with two alkyl substituents
R1R2Pip	Piperidinium cation with two alkyl substituents
R1R2Pyr	Pyridinium cation with two alkyl substituents
R1R2Pyrr	Pyrolidinium cation with two alkyl substituents
R1R2R3Im	Imidazolium cation with three alkyl substituents
R1R2R3R4A	Ammonium cation with four alkyl substituents
R1R2R3R4Thi	Thiazolium cation with four alkyl substituents
R1R2R3S	Sulphonium cation with three alkyl substituents
R1R2R3Si	Silyl cation with three alkyl substituents
Anions
[BF4]	Tetrafluoroborate
[C(CN)3]	Tricyanomethanide
[DCA]	Dicyanamide
[Doc]	bis(2-ethylhexyl)sulfosuccinate
[ESU]	Ethyl sulfate
[Et2PO4]	Diethylphosphate
[EtOAc]	Ethoxyacetate
[FAP]	Trifluoro phosphate
[Gly]	Glycolate
[Inda]	Indazolide
[Lac]	L(+) lactate
[Lev]	Levulinate
[Mal]	Malonate
[Me2PO4]	Trimethylphosphate
[PF6]	Hexafluorophosphate
[Pho]	Phenolate
[Pro]	Proline
[Pro]	Prolinate
[Tf2N]	bis(trifluoromethylsulfonyl)imide
[TfA]	Trifluoroacetate
[TfO]	Trifluoromethane sulfonate
Ac	Acetate
B(CN)4	Tetracyanoborate
BF4	Tetrafluoroborate
C(CN)3	Tricyanomethanide
DCA or N(CH)2	Dicyanamide
PF6	Hexafluorophosphate
RPO4	Alkyl phosphate
RSO4	Alkyl sulfate
Tf2N	Bis(trifluoromethylsulfonyl)imide
TfO	Trifluoromethylsulfonate
TFSI (=Tf2N)	Bis(trifluoromethylsulfonyl)imide
Polymers and PILs
6FDA-TeMPD	(Hexafluoroisopropylidene)dephthalic anhydride and 2,3,5,6-tetramethyl- 1,4-phenylene diamine-based polyimide
p(VDF-HFP)	Poly(vinylidene fluoride-co-hexafluoropropylene) fluoroelastomer
p[MABI][BF4]	Poly(1-[2-(methacryloyloxy)ethyl]-3-butyl-imidazolium) tetrafluoroborate
p[MATMA][BF4]	poly[2-(methacryloyloxy)ethyl]trimethylammonium tetrafluoroborate
p[VBBI][BF4]	Poly(1-(p-vinylbenzyl)-3-butyl-imidazolium) tetrafluoroborate
p[VBIM][DCA]	1-vinyl-3-butylimidazolium dicyanamide
p[VBTMA][BF4]	poly[1-(para-vinylbenzyl)-triethylammonium tetrafluoroborate
p[VBTMA][PF6]	poly[1-(para-vinylbenzyl)-triethylammonium hexafluorophosphate
p[VBTMA][Tf2N]	poly[1-(para-vinylbenzyl)-triethylammonium bis(trifluoromethylsulfonyl)imide
p[VEIM][DCA]	polymerized 1-vinyl-3-ethylimidazolium dicyanamide
p[VHIM][DCA]	1-vinyl-3-heptylimidazolium dicyanamide
P4VP	Poly(4-vinylpyridine)
PAA	Poly acrylic acid or Sodium polyacrylate
PAH	Poly(allylamine) hydrochloride
PAMPS	Poly(2-acrylamido-2-methyl-1-propanesulfonic acid)
PAN	Polyacrylonitrile
PBI	Polybenzimidazole
PC	Polycarbonate
PDADMAC	Poly(diallyldimethylammonium) chloride
PDMAAm	Polydimethylacrylamide
PDMAEMA	Poly(N,N-dimethyl aminoethylmethacrylate)
PDMS	Polydimethylsiloxane
PEG	Polyethylene glycol
PEI	Poly(ethyleneimide)
PES	Polyethersulfone
PI	Polyimide
PMAPTAC	Poly(methacryloylamino propyl trimethylammonium chloride)
PMDA-ODA PI	Poly(pyromellitimide-co-4,4′-oxydianiline) polyimide
PMMA	Polymethylmethacrylate
Poly(SEOS)	Poly(styrene-block-ethylene oxide-block-styrene)
PSf	Polysulfone
PSS	Polystyrene sulphonate or Sodium polystyrene sulphonate
PTFE	Polytetrafluoroethylene
PTMEG	Polytetramethylene Ether Glycol
PTMSP	Poly(1-trimethylsilyl-1-propyne)
PU	Polyurethane
PVAc	Poly(vinyl) acetate
PVBC	Polyvinyl benzyl chloride
PVBTMAC	Poly(4-vinylbenzyltrimethylammonium) chloride
PVDF	Polyvinylidene fluoride
PVP	Polyvinylpyrrolidone