The novel copolymerization polyimide (PI) hollow fibers (HFs) of 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) containing –CF3 groups were prepared and investigated through both simulation and experiment. To demonstrate the alteration attributable to the introduction of fluoromonomers, the condensed states of pyromellitic dianhydride (PMDA)/4,4′-oxybisbenzenamine (ODA), PMDA/6FDA/ODA, and 6FDA/ODA PI were constructed by Material Studio, and we simulated the mobility of molecular chain, free volume fraction, and O2/N2 dissolution–diffusion process. The molecular dynamics simulation results demonstrated that the properties of the copolymerized PI system with 6FDA were significantly improved, while the selectivity remained almost unchanged. Then, the films of copolymerized PI and HFs were prepared by the two-step method, and O2/N2 permeability of the PI copolymer films was characterized, indicating that although the gas permeation performance was greatly improved, the selectivity was not so satisfactory. However, the selection factor increased heavily after polydimethylsiloxane coating.
WilsonDStenzenbergerHDHergenrotherPM. Polyimides. Glasgow: Blackie & Son Limited, 1990.
2.
GhoshMKMittalKL. Polyimides: fundamentals and applications. New York: Marcel Dekker, 1996.
3.
NisolaGMBeltranABAfricaVJL, et al.Carbon dioxide and methane gas permeations in thermally annealed and chemically cross-linked commercial polyimide hollow fiber. Fibers Polym2011; 12(5): 572–579.
4.
ChenarMPSavojiHSoltaniehM, et al.Removal of hydrogen sulfide from methane using commercial polyphenylene oxide and Cardo-type polyimide hollow fiber membranes. Korean J Chem Eng2011; 28(3): 902–913.
5.
ChenarMPSoltaniehMMatsuuraT, et al.Gas permeation properties of commercial polyphenylene oxide and Cardo-type polyimide hollow fiber membranes. Sep Purif Technol2006; 51: 359–366.
6.
ParkHBKamcevJRobesonLM, et al.Maximizing the right stuff: the trade-off between membrane permeability and selectivity. Science2017; 356: 1137.
7.
RobesonML. The upper bound revisited. J Membr Sci2008; 320(1–2): 390–400.
8.
PetersenJMatsudaMHarayaK, et al.Capillary carbon molecular sieve membranes derived from Kapton for high temperature gas separation. J Membr Sci1997; 131: 85–94.
9.
BaCEconomyJ. Preparation of PMDA/ODA polyimide membrane for use as substrate in a thermally stable composite reverse osmosis membrane. J Membr Sci2010; 363: 140–148.
10.
KimMKimGKimJ, et al.New continuous process developed for synthesizing sponge-type polyimide membrane and its pore size control method via non-solvent induced phase separation (NIPS). Microporous Mesoporous Mater2017; 242: 166–172.
11.
KanedaTKatsuraTNakagawaK, et al.High-strength–high-modulus polyimide fibers II. Spinning and properties of fibers. J Appl Polym Sci2010; 32: 3151–3176.
12.
TanakaKKitaHOkanoM, et al.Permeability and permselectivity of gases in fluorinated and non-fluorinated polyimides. Polymer1992; 33(3): 585–592.
13.
QiuWXuLChenCC, et al.Gas separation performance of 6FDA-based polyimides with different chemical structures. Polymer2013; 54: 6226–6235.
14.
MinKKimYGoyalS, et al.Interfacial adhesion behavior of polyimides on silica glass: a molecular dynamics study. Polymer2016; 98: 1–10.
15.
CalleMGarcíaCLozanoAE, et al.Local chain mobility dependence on molecular structure in polyimides with bulky side groups: correlation with gas separation properties. J Membr Sci2013; 434: 121–129.
16.
NeyertzSBrownD. Molecular dynamics simulations of oxygen transport through a fully atomistic polyimide membrane. Macromolecules2008; 41: 2711–2721.
Ghasemnejad-AfsharEAmjad-IranaghSZarifM, et al.Effect of side branch on gas separation performance of triptycene based PIM membrane: a molecular simulation study. Polym Test2020; 83: 106339.
19.
DuttaRCBhatiaSK. Interfacial engineering of MOF-based mixed matrix membrane through atomistic simulations. J Phys Chem C2019; 124: 594–604.
20.
PanRLiuXZhangA, et al.Molecular simulation on structure–property relationship of polyimides with methylene spacing groups in biphenyl side chain. Comput Mater Sci2006; 39: 887–895.
21.
McKenzieMEGoyalSLeeSH, et al.Adhesion of organic molecules on silica surfaces: a density functional theory study. J Phys Chem C2016; 121: 392–401.
22.
LowBTXiaoYChungTS. Amplifying the molecular sieving capability of polyimide membranes via coupling of diamine networking and molecular architecture. Polymer2009; 50: 3250–3258.
23.
LiMLaiHChenBX, et al.Effect of a biphenyl side chain of polyimide on the pretilt angle of liquid crystal molecules: molecular simulation and experimental studies. Liq Cryst2010; 37(2): 149–158.
24.
LeiHQiSWuD. Hierarchical multiscale analysis of polyimide films by molecular dynamics simulation: investigation of thermo-mechanical properties. Polymer2019; 179: 121645.
25.
LiPChenHZChungTS. The effects of substrate characteristics and pre-wetting agents on PAN–PDMS composite hollow fiber membranes for CO2/N2 and O2/N2 separation. J Membr Sci2013; 434: 18–25.
26.
ChangKSTungCCWangKS, et al.Free volume analysis and gas transport mechanisms of aromatic polyimide membranes: a molecular simulation study. J Phys Chem B2009; 113(29): 9821–9830.
27.
PranamiGLammMH. Estimating error in diffusion coefficients derived from molecular dynamics simulations. J Chem Theory Comput2015; 11: 4586–4592.
28.
HeuchelMHofmannD. Molecular modelling of polyimide membranes for gas separation. Desalination2002; 144: 67–72.
29.
MaXZhengFvan SittertCGCE, et al.Role of intrinsic factors of polyimides in glass transition temperature: an atomistic investigation. J Phys Chem B2019; 123: 8569–8579.
30.
ChangKSWuZCKimS, et al.Molecular modelling of poly(benzoxazole-co-imide) membranes: a structure characterization and performance investigation. J Membr Sci2014; 454: 1–11.
31.
LiTLiuJZhaoS, et al.Microporous polyimides containing bulky tetra-o-isopropyl and naphthalene groups for gas separation membranes. J Membr Sci2019; 585: 282–288.
32.
AmaniMAmjad-IranaghSGolzarK, et al.Study of nanostructure characterizations and gas separation properties of poly(urethane–urea)s membranes by molecular dynamics simulation. J Membr Sci2014; 462: 28–41.
33.
TongHHuCYangS, et al.Preparation of fluorinated polyimides with bulky structure and their gas separation performance correlated with microstructure. Polymer2015; 69: 138–147.
34.
JiangLYWangYChungTS, et al.Polyimides membranes for pervaporation and biofuels separation. Prog Polym Sci2009; 34: 1135–1160.
35.
ChungTSKafchinskiER. The effects of spinning conditions on asymmetric 6FDA/6FDAM polyimide hollow fibers for air separation. J Appl Polym Sci1997; 65: 1555–1569.
36.
VolginIVAndreevaMVLarinSV, et al.Transport properties of thermoplastic R-BAPB polyimide: molecular dynamics simulations and experiment. Polymers2019; 11: 1775.
37.
AziziMMousaviSA. CO2/H2 separation using a highly permeable polyurethane membrane: molecular dynamics simulation. J Mol Struct2015; 1100: 401–414.
