Dataset underlying the publication:  "Improving the fixed charge density of sustainably produced saloplastic anion exchange membranes"
DOI	https://doi.org/10.1039/D5SU00221D
License: Creative‑Commons Attribution 3.0 Unported (CC BY 3.0)
Data collection: This data was collected at the Department of Membrane Science and Technology and Department of Molecules and Materials, University of Twente, Enschede.
Funding: This project is sponsored by the Dutch science foundation NWO under grant number NWA.1237.18.007

Authors & Affiliations
Hestie A. Brink – Department of Membrane Science and Technology, University of Twente, Enschede, Netherlands
Ricardo P. Martinho – Department of Molecules and Materials, University of Twente, Enschede, Netherlands
Wiebe M. de Vos – Department of Membrane Science and Technology, University of Twente, Enschede, Netherlands
Saskia Lindhoud - Department of Molecules and Materials, University of Twente, Enschede, Netherlands

Corresponding author: 
Saskia Lindhoud
s.lindhoud@utwente.nl


Data Description
This dataset supports the study aimed at enhancing the fixed charge density of saloplastic anion exchange membranes derived from non-stoichiometric PSS–PDADMAC polyelectrolyte complexes (PECs). The strategy involved overcharging the complexes with PDADMAC during the complexation step.

Five different PECs were prepared with 0, 10, 20, 30, and 40 mol% excess PDADMAC and labeled as C1 through C5 (see the PEC file for preparation details). Membranes were fabricated by hot-pressing the hydrated PECs into thin, dense films. Multiple membranes were made from each PEC and labeled using the format C#_M#, where C# corresponds to the PEC number and M# to the membrane number. Each membrane was cut into smaller test samples, labeled alphabetically (e.g., C1_M1 A indicates sample A from membrane 1 made with PEC C1).

All data and experimental conditions are included in the respective files described below:

PEC
Contains the calculations and preparation details for the five PECs. Polyelectrolyte solutions were mixed in varying PDADMAC excess (0–40 mol%) by simultaneously pouring them into a third beaker under stirring for 15 minutes to form PEC precipitates.

NMR_IEC
Includes data from NMR analysis used to determine the molar ratios of polyelectrolytes and the resulting ion exchange capacity (IEC). Results are given for both pristine membranes (after hot-pressing) and used membranes (after testing and soaking in 0.5 M KCl for at least 90 days).

Water_Uptake
Provides water uptake results for membranes soaked in 0.1, 0.3, and 0.5 M KCl. Wet weights were recorded after 24 hours of soaking at 25°C, followed by blotting. Dry weights were measured after drying at 80°C until constant mass.

Permselectivity
Measurements were performed using a two-chamber system circulating different KCl concentrations. The format X/Y refers to the KCl concentrations in chamber 1 and chamber 2, respectively. Membranes were tested under three concentration gradients: 0.02/0.1 M, 0.06/0.3 M, and 0.1/0.5 M KCl at 25°C.

Conductivity
Contains resistance, resistivity, and conductivity data of membranes tested in 0.1, 0.3, and 0.5 M KCl. The testing setup included six compartments: 1 and 6 with 0.5 M K₂SO₄, 2 and 5 with 0.5 M KCl, and 3 and 4 with varying KCl concentrations (0.1, 0.3, and 0.5 M KCl). A schematic of the experimental setup is available in the supplementary information of the associated publication.

