PFAS-free amphiphilic surfactant compositions for firefighting foam, electroplating, and semiconductor processes

The global PFAS phase-out is not a voluntary transition — it is a forced substitution event driven by converging regulatory mandates. The U.S. EPA NESHAP rules, the EU REACH restriction on per- and polyfluoroalkyl substances, and the Department of Defense's statutory deadline to eliminate aqueous film-forming foam (AFFF) from military installations collectively eliminate the incumbent chemistry across firefighting, electroplating, semiconductor fabrication, and metalworking fluids simultaneously. There is no graceful multi-year migration path for formulators: the regulatory cliff is sharp, the performance requirements are uncompromising, and PFAS alternatives that actually match surface-tension targets (below 20 mN/m for AFFF spreading) have historically not existed in non-fluorinated form. This invention sits precisely at that gap. The critical insight behind this filing is that no single non-fluorinated head group or tail architecture achieves PFAS-level surface tension across all four application verticals. The prior-art response has been to propose generic zwitterionic or polyglucoside surfactants as replacements, but these are application-agnostic and routinely fail on one or more performance axes — spreading coefficient, foam stability, chrome-bath fume suppression efficacy, or semiconductor-process compatibility. This invention instead claims application-matched functional pairs: a defined set of zwitterionic head groups (alkyl polyglucoside, hydroxysultaine, betaine, phosphonium-sulfobetaine) specifically paired with siloxane or hyperbranched hydrocarbon tails, selected per application vertical. The pairing is the invention — the specific functional combination predicted by air-water interface molecular dynamics, for the siloxane-sulfobetaine combination only, to reach a surface tension of 15–22 mN/m without any fluorinated C2+ alkyl chain. Within the critical-mineral recovery and recycling separations portfolio, this asset plays a dual role: it is a lead composition filing that covers the broadest commercially important non-fluorinated amphiphile space, and it functions as the anchor of a freedom-to-operate carve-out strategy that navigates around the dense prior-art landscape of generic betaine and APG personal-care surfactants. The claim structure is deliberately application-specific to create enforceable novelty where generic structural claims would fail.

The material class here is not a single crystalline compound but a structured family of amphiphilic molecules defined by the combination of head-group chemistry and tail architecture, with each combination targeted to a specific application environment. The head-group set spans alkyl polyglucoside (APG), hydroxysultaine, betaine, aromatic sulfonate, taurate, sarcosinate, and phosphonium-sulfobetaine. The tail set spans C8–C18 linear and branched alkyl chains, siloxane-sulfobetaine hybrids, and hyperbranched polyester architectures. The key performance target is surface tension in the range of 15–22 mN/m at the air-water interface — a range that encompasses conventional AFFF performance and is substantially below what generic non-fluorinated surfactants achieve. Reaching below 20 mN/m without fluorine requires either siloxane backbone elements, which spread via a fundamentally different adsorption geometry than linear alkyl chains, or hyperbranched tails that pack at the interface with unusually high density relative to molecular weight. Both strategies are represented in the claim family. The primary computational validation method is air-water interface molecular dynamics simulation. This is a well-established simulation protocol for predicting surfactant surface tension: a slab of explicit water molecules is assembled with the amphiphile molecules adsorbing at the upper and lower vacuum interfaces, and the surface tension is extracted from the diagonal components of the pressure tensor averaged over a production trajectory. Simulation Example 24 in the specification targets the siloxane-sulfobetaine combination specifically and reports a predicted surface tension consistent with the 15–22 mN/m target window. This is the most computationally rigorous entry in the series and provides the quantitative anchor for the claim range. For the other head-group/tail combinations, the simulation framework supports the plausibility of the surface-tension target, but the individual MD predictions for each pair are the proximate evidence rather than a single consensus value across all variants. It is important to be precise about what the multi-engine phonon consensus machinery of the broader portfolio contributes here: the MACE, CHGNet, MatterSim, and ORB potential ensemble, and the associated dynamic stability screening, is designed for periodic crystalline inorganic solids. Amphiphilic surfactant molecules in solution are molecular species for which force-field molecular dynamics — not machine-learning interatomic potentials calibrated on inorganic crystal structures — is the appropriate simulation tool. The computational proof for this asset therefore relies on classical and semi-empirical molecular mechanics force fields applied to explicit-solvent interface MD, not the inorganic-materials-stability pipeline used elsewhere in the portfolio. This distinction matters for any buyer evaluating the nature of the computational evidence. The application-pairing logic has a real physicochemical basis. In AFFF formulations, the surfactant must achieve a spreading coefficient over hydrocarbons while simultaneously forming a coherent aqueous film; this demands both low surface tension and a specific balance of hydrophilic-lipophilic character that betaine alone (as used in personal care) does not provide. In electroplating chrome-bath fume suppression, the surfactant must function in highly acidic, high-ionic-strength bath conditions where many zwitterionics are protonated and lose their amphiphilic character — the phosphonium-sulfobetaine head group is specifically chosen for pH stability in this environment. In semiconductor photolithographic etch and rinse steps, compatibility with dilute HF and buffered oxide etch chemistries, and the absence of metal-ion contamination, drive selection toward the sulfobetaine and hydroxysultaine variants. In metalworking fluids, the antifoam requirement inverts the usual design logic: excess foam must be suppressed, not generated, and the hyperbranched tail architectures are predicted to reduce dynamic foam stability while maintaining lubricity.

The total addressable market for PFAS-free surfactant alternatives across the four application verticals is estimated at $1–3 billion annually, with the caveat that this estimate reflects the full market opportunity at the time of forced substitution, not a niche-capture scenario. Firefighting foam alone represents a substantial fraction: the U.S. military operates thousands of airfield and shipboard AFFF systems, the Federal Aviation Administration mandates AFFF at certified airports, and municipal fire departments represent an additional volume. The DoD has statutory phase-out deadlines under the National Defense Authorization Act; compliance is not discretionary, and qualified PFAS-free alternatives command significant premium pricing because the alternative to qualification is operational non-compliance rather than continued use of incumbent chemistry. Electroplating and chrome-fume suppression represents a second large market segment. Hard chrome plating remains a critical industrial process for aerospace components, hydraulic systems, and tooling, and fume suppression in chrome baths is required under OSHA 1910.1026. The PFAS-containing fume suppressants currently used (primarily perfluorooctane sulfonyl-based compounds) are either already restricted or pending restriction under REACH and the Stockholm Convention. Formulators serving this segment must qualify alternatives before their existing inventory is exhausted or banned, creating a pull-through dynamic independent of price. Semiconductor process chemicals represent the highest-value but most demanding qualification path. Surfactants used in photolithographic rinse steps, post-etch cleans, and chemical-mechanical planarization require sub-ppb metal impurity levels, extremely low particle counts, and demonstrated compatibility with device yield metrics. Licensing into a qualified chemistry supplier for this segment would more plausibly occur as a formulation license or supply agreement than as a direct product sale. Metalworking fluids are a higher-volume, lower-margin segment where the PFAS-free driver is primarily regulatory (REACH restriction on certain fluorotelomer compounds) rather than performance-driven, and where price sensitivity is higher. Royalty or licensing economics would reasonably be structured differently across these four verticals — a per-kilogram royalty or formulation license for AFFF and plating, and a technology-access or supply-exclusivity fee structure for semiconductor process chemicals.

candidate PFAS-free drop-in (to be shown) under EPA NESHAP / EU REACH / DoD AFFF phase-out

application-specific functional pair vs generic APG/betaine art

Preliminary screen only. This is not a freedom-to-operate opinion.

The most strategically aligned acquirers or licensees are specialty chemical companies that currently supply PFAS-containing formulations to one or more of the four target verticals and face an existential need to qualify replacements before regulatory deadlines. Chemours, Dynax (now part of Daikin), and the remaining fluorosurfactant suppliers have public commitments to exit PFAS product lines and need defensible alternative IP to license to their existing customers rather than cede market share. In electroplating, MacDermid Enthone and Atotech (now part of MKS Instruments) are the dominant global suppliers of chrome-bath additives and have publicly stated PFAS-replacement programs. In semiconductor process chemicals, Stella Chemifa, Honeywell Specialty Materials, and the major electronic-grade chemical suppliers represent the highest-value licensing path, though their qualification timelines are measured in years. Beyond strategic acquirers, this asset is well-suited to a licensing model with application-specific sub-licenses: the AFFF sublicense, the plating sublicense, the semiconductor sublicense, and the metalworking fluids sublicense can be structured independently, allowing the owner to capture value from multiple verticals without requiring a single buyer to operate across all four. Defense procurement primes (Raytheon, L3Harris, General Dynamics) that manufacture or maintain AFFF-equipped systems may also have direct interest in holding or co-licensing the IP to manage their own PFAS remediation liability exposure.

The principal technical risk is the gap between the MD-predicted surface tension of 15–22 mN/m and full physical qualification, particularly for AFFF. Surface tension prediction from simulation is reasonably reliable for pure amphiphile systems, but real AFFF formulations are multicomponent — they contain cosolvents, corrosion inhibitors, freeze-point depressants, and polymer thickeners — and the interactions among these components can substantially alter the effective surface tension and foam behavior. Synthesis and bench testing of the siloxane-sulfobetaine lead candidate, followed by formulation into a representative AFFF concentrate and MIL-PRF-24385 burn-back testing, is the critical de-risking step. The cost of this work is modest relative to the market opportunity, and it could plausibly be carried out by a strategic partner under a co-development agreement rather than requiring the patent holder to fund it unilaterally. The prosecution risk is real but manageable. The prior-art density for betaine and APG surfactants in personal-care and cleaning applications is high, and examiners may challenge the structural claims as anticipated or obvious. The mitigation strategy is clear: rely on the application-specific pairing claims, the negative limitations, and the surface-tension simulation data as evidence of unexpected results in the 15–22 mN/m range for non-fluorinated systems. Competitive risk from well-capitalized incumbents filing their own PFAS-replacement surfactant IP should be monitored closely during prosecution.