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oai:figshare.com:article/34031186 2026-09-30T10:04:33Z category_4 category_146 category_7 category_21 category_272 category_873 category_46 portal_63 item_type_6 month_year_09_2026

Decoupling Wetting from Swelling in Electrospun Fibrous Mats: Predicting Saturation Time, Swelling Time, and Dimensional Change from Solubility Parameters Pitt Supaphol (554451) Biochemistry Space Science Medicine Biotechnology Environmental Sciences not elsewhere classified Chemical Sciences not elsewhere classified Immunology weighting dispersion differently scale laplace pressure plane wicking anisotropic link density reproducing jamming argument closes framework applies unmodified film pair returns apparent contact angle absolute permeability measurements fiber orientation makes second squared distance predicting saturation time hansen solubility parameters two independent gates two branches separately aligned mat wets electrospun fibrous mats droplet yet imbibes functioning wet one characterized dry mat one hydrophilic mat fiber swelling ratio imb </ sub exactly </ b 2 </ sup hansen distance fiber diameter ≈ 2 used wet dry porosity swelling time one coefficient σ </ μ </ θ </ β </ r </ mat porosity k </ >< sub wound dressings void terms vinyl alcohol scaled coordinates releasing membranes rarely quantified Electrospun mats are used wet, yet the transition from the characterized dry mat to the functioning wet one is rarely quantified. The Hansen solubility parameters of a polymer and a liquid generate two distinct metrics rather than one, and so two independent gates: the Flory–Huggins parameter follows from the Hansen distance, while the polymer–liquid interfacial tension collapses <b>exactly</b> onto a second squared distance on volume-scaled coordinates, weighting dispersion differently by 4<i>β</i> ≈ 2.5. Wetting and swelling are consequently separable, and four regimes exist rather than two. The pore-scale Laplace pressure and a Kozeny–Carman permeability reduce capillary imbibition to one coefficient, <i>D</i>_imb = <i>ε</i>₀<i>R</i>_f<i>σ</i> cos <i>θ</i>/[<i>k</i>_K(1 – <i>ε</i>₀)<i>μ</i>], which saturates a mat through its thickness in 10 to 50 ms. Fiber orientation makes in-plane wicking anisotropic, so an aligned mat wets into an ellipse of axis ratio √2. A closed gate instead imposes a 14 kPa intrusion pressure; the mat stays dry unless the interior drive is favorable, in which case it resists a droplet yet imbibes once entry has occurred. Fiber swelling completes within 10² s, and a jamming argument closes the dimensional-change problem, giving a porosity linear in the fiber swelling ratio and an exact decomposition of gravimetric uptake into network and void terms. Against published data, a cellulose acetate (CA) mat-and-film pair returns a mat porosity of 0.90 with no adjustable parameter, and a cross-linked poly(vinyl alcohol) (PVA) series a monotonic cross-link density reproducing the reported cross-linker ranking. A swelling ratio reported without the dry porosity is not interpretable: for one hydrophilic mat, 54% of the uptake is capillary water between the fibers, not water in the polymer. Two independent datasets test the two branches separately: the wetting gate against poly(ε-caprolactone) (PCL) mats that absorb a water droplet completely despite an apparent contact angle of 137.9°, and the Kozeny–Carman baseline against absolute permeability measurements on poly(lactic acid) (PLA) scaffolds several times coarser in fiber diameter. The framework applies unmodified to microfluidic and tissue-engineering scaffolds as well as to wound dressings, drug-releasing membranes, separators and filtration media. 2026-09-30T00:00:00Z Text Journal contribution 10.1021/acs.langmuir.6c05201.s001 https://figshare.com/articles/journal_contribution/Decoupling_Wetting_from_Swelling_in_Electrospun_Fibrous_Mats_Predicting_Saturation_Time_Swelling_Time_and_Dimensional_Change_from_Solubility_Parameters/34031186 CC BY-NC 4.0