Polyquaternium-10

Lue, Zhenhua, et al. Desalination 564 (2023): 116755.

Polyquaternium-10 (PQ10), a cationic cellulose derivative, was employed as a functional additive in the fabrication of polyvinyl alcohol (PVA)-based coating layers on polyamide (PA) reverse osmosis (RO) membranes to enhance water permeation, fouling resistance, and chemical stability. The coating process involved surface soaking of air-dried, water-cleaned PA membranes in an aqueous solution containing PVA, PQ10, 0.1 wt% sulfuric acid, and 0.5 wt% glutaraldehyde (GA). The membranes were soaked for 5 min, drained, air-dried, and subsequently heat-treated at 60 °C for 8 min to achieve cross-linking. Coating compositions varied from 0–2.0 wt% PVA and 0–0.25 wt% PQ10, enabling optimization of performance parameters.

Incorporation of PQ10 into the PVA layer significantly reduced hydraulic resistance from 5.9 × 10¹² m⁻¹ (PVA-only) to 2.5 × 10¹² m⁻¹ (PVA/PQ10), indicating enhanced water permeability. Anti-fouling evaluations demonstrated superior resistance to both negatively and positively charged foulants, attributed to PQ10's pseudo-zwitterionic surface character and reduced surface charge density. Long-term filtration tests using dye wastewater revealed that PVA/PQ10-coated membranes maintained higher salt rejection, lower flux decline, and larger cumulative permeate volumes over 48 h compared to unmodified RO membranes.

Furthermore, soaking tests confirmed improved chemical durability of the coated membranes against acidic, alkaline, and chlorine-containing environments. The study highlights polyquaternium-10 as an effective additive for preparing PVA-based surface coatings that simultaneously enhance permeability, fouling resistance, and chemical robustness of RO membranes, providing a practical approach for the development of high-performance water treatment technologies.

Yi, B., Liu, L., He, H., Yu, S., Wu, D., & Gao, C. (2025). Desalination, 601, 118586.

Polyquaternium-10 (PQ-10), a cationic cellulose derivative, was utilized as a surface modifier to enhance the dye/salt separation performance of polyamide (PA)-based loose nanofiltration (NF) membranes for textile wastewater treatment. The fabrication involved interfacial polymerization on polysulfone (PSF) support membranes, using piperazine (PIP) as the aqueous-phase monomer, trimesoyl chloride (TMC) as the organic-phase monomer, and diethanolamine (DEA) as an aqueous-phase additive to modulate membrane structure.

Initially, hydrated PSF membranes were mounted on an epoxy casting platform and contacted with the PIP/DEA solution containing SDS and Na3PO4·12H2O for 3 min, followed by draining and air-drying. The TMC solution was then applied for 30 s to initiate interfacial polymerization, followed by oven thermal treatment at 80 °C for 4 min and thorough washing. Subsequently, membranes were immersed in a PQ-10 aqueous solution for surface modification, rinsed with deionized water, and stored for further testing.

Structural characterization revealed a substantial decrease in surface zeta potential at pH 7.0, from −28.9 mV to −2.0 mV, while molecular weight cut-off (MWCO) increased from 360 to 2340 Da, and pore radius expanded from 0.28 to 0.64 nm. These modifications enhanced water permeability to 420.4 L m⁻² h⁻¹ MPa⁻¹ and maintained 98.9 % rejection of Congo red dye while lowering Na2SO4 rejection to 10.3 %. Long-term tests over 50 h demonstrated stable dye/salt separation, confirming operational durability.

This study demonstrates that polyquaternium-10 serves as an effective surface modifier for constructing weakly charged NF membranes, optimizing the balance between permeability and selectivity, and offering a scalable strategy for industrial dye wastewater treatment.

Ji, Xiaoyu, et al. Journal of Industrial and Engineering Chemistry (2025).

Polyquaternium-10 (PQ-10), a quaternized cationic cellulose derivative, was employed as a surface modifier to enhance the performance of 3,5-diaminobenzoic acid (DABA)-based nanofiltration (NF) membranes for advanced water treatment applications. The fabrication involved a two-step process combining interfacial polymerization and PQ-10 grafting.

Initially, hydrophilic PVDF membranes were submerged in an aqueous DABA solution for 5 min, followed by immersion in n-hexane containing trimesoyl chloride (TMC) to form a crosslinked NF layer via interfacial polymerization. The resulting membranes, designated D NF membranes, were then thermally cured to reinforce crosslinking. Subsequently, the D NF membranes were immersed in an aqueous PQ-10 solution for 15 min, followed by oven treatment, producing the PQ-10 grafted membranes, denoted DP NF membranes. The grafting process was verified through XPS and FTIR analysis, confirming the successful incorporation of PQ-10, while SEM and AFM imaging revealed a smooth, uniform membrane surface.

Functional evaluation demonstrated that DP NF membranes exhibited enhanced hydrophilicity, with water contact angles decreasing from 67.1° (PVDF) to 30.7°. The water flux reached 33.7 L·m⁻²·h⁻¹, while MgSO₄ and Na₂SO₄ rejection rates were 96.4 % and 94.1 %, respectively.

Antifouling performance was exceptional, with flux recovery ratios exceeding 95 % for bovine serum albumin, humic acid, sodium alginate, and oil/water emulsion, maintaining stability over three fouling cycles and 100 h of long-term operation.

This study highlights polyquaternium-10 as an effective surface modifier for constructing high-permeability, durable, and antifouling NF membranes, offering a facile strategy for scalable fabrication in industrial and municipal water treatment applications.