title: Microwave-assisted grafting polymerization modification of nylon 6 capillary-channeled polymer fibers for enhanced weak cation exchange protein separations.
abstract: A weak cation exchange liquid chromatography stationary phase (nylon-COOH) was prepared by grafting polyacrylic acid on to native nylon 6 capillary-channeled polymer (C-CP) fibers via a microwave-assisted radical polymerization. To the best of our knowledge, this is the first study of applying microwave-assisted grafting polymerization to affect nylon material for protein separation. The C-CP fiber surfaces were characterized by attenuated total reflection (ATR) infrared spectroscopy and scanning electron microscope (SEM). The anticipated carbonyl peak at 1722.9 cm-1was found on the nylon-COOH fibers, but was not found on the native fiber, indicating the presence of the polyacrylic acid on nylon fibers after grafting. The nylon-COOH phase showed a ∼12× increase in lysozyme dynamic binding capacity (∼12 mg mL-1) when compared to the native fiber phase (∼1 mg mL-1). The loading capacity of the nylon-COOH phase is nearly independent of the lysozyme loading concentration (0.05-1 mg mL-1) and the mobile phase linear velocity (7.3-73 mm s-1). The reproducibility of the lysozyme recovery from the nylon-COOH (RSD = 0.3%, n = 10) and the batch-to-batch variability in the functionalization (RSD = 3%, n = 5) were also investigated, revealing very high levels of consistency. Fast baseline separations of myoglobin, α-chymotrypsinogen A, cytochrome c and lysozyme were achieved using the nylon-COOH column. It was found that a 5× increase in the mobile phase linear velocity (7.3-to-36.5 mm s-1) had little effect on the separation resolution. The microwave-assisted grafting polymerization has great potential as a generalized surface modification methodology across the applications of C-CP fibers.
authors.affiliation: Clemson University, Department of Chemistry, Biosystems Research Complex, Clemson, SC 29634, United States.
authors.forename: Liuwei
authors.initials: L
authors.lastname: Jiang
authors.affiliation: Clemson University, Department of Chemistry, Biosystems Research Complex, Clemson, SC 29634, United States. Electronic address: marcusr@clemson.edu.
authors.forename: R Kenneth
authors.initials: RK
authors.lastname: Marcus
mesh_terms: D017920:Antiporters; D002209:Caprolactam / Q000031:analogs & derivatives*; D002852:Chromatography, Ion Exchange; D008872:Microwaves; D058105:Polymerization; D011108:Polymers; D011506:Proteins / Q000302:isolation & purification*; D015203:Reproducibility of Results
chemical_list: D017920:Antiporters; D011108:Polymers; D011506:Proteins; C009916:nylon 6; D002209:Caprolactam
keywords: Capillary-channeled polymer; Chromatography; Fiber; Ion exchange; Microwave-assisted polymerization; Surface modification