Mechanism

Naive incorporation of FJH-derived turbostratic graphene into Portland-cement or geopolymer matrices exposes the graphene flakes to an early-hydration pore solution whose pH typically rises into the range of approximately 12 to 13. Three distinct degradation pathways act on the hierarchical pore network in this environment. First, edge functional groups (carboxyl, hydroxyl, lactone) on the graphene flakes hydrolyze under hydroxide attack, removing the steric and electrostatic stabilization that keeps individual flakes dispersed. Second, dehydroxylated flakes aggregate face-to-face under van der Waals attraction, collapsing mesopore and macropore volume into densified stacks. Third, calcium ions in the pore solution bridge between adjacent flakes, locking the collapsed stacks against later re-dispersion. The composite that emerges from naive mixing retains essentially all of the graphene mass that was added but loses an order of magnitude or more of BET specific surface area relative to the as-FJH-produced material, and the macropore fraction that is most important for ion transport during charge and discharge is preferentially destroyed.

The disclosed mechanism interrupts each of the three degradation pathways. A buffering admixture moderates the early-hydration pore-solution pH into a window in which edge functional groups remain protonated and stable. A surface pre-treatment converts a fraction of the edge groups into alkali-stable functionalization that resists hydrolysis even at the buffered pH. A dispersant admixture maintains electrostatic and steric stabilization between flakes against the residual aggregation drive, and a calcium-sequestering admixture removes free calcium from the immediate flake environment during the critical first hours of hydration so that bridging cannot lock collapsed stacks into the cured matrix. The four interventions together preserve hierarchical porosity through the setting reaction; their omission individually permits one or more of the degradation pathways to proceed and destroys surface area accordingly.

Operating Parameters

The operating parameters of the preservation primitive are organized as five declared quantities. The first is the buffered pH window: the disclosed primitive specifies an early-hydration pore-solution pH preferably in the range of approximately 10.5 to 11.5, achieved by buffering admixture loading proportional to the cementitious binder mass. The second is the graphene loading: typically in the range of approximately 0.05 to 5.0 percent by mass of binder, with the upper end constrained by workability and the lower end constrained by percolation of the storage network. The third is the cure temperature profile: a controlled isothermal hold preferably in the range of approximately 20 to 30 degrees Celsius for at least the first 24 hours of hydration, suppressing thermal acceleration of the degradation pathways and preserving slow, dispersion-friendly setting. The fourth is the dispersant-to-graphene mass ratio: typically in the range of approximately 0.5:1 to 5:1 depending on the specific surface area of the as-produced graphene. The fifth is the calcium-sequestering admixture loading: titrated against the free-calcium evolution of the specific binder system, sufficient to suppress flake-to-flake calcium bridging during the buffered pH window without depriving the binder of the calcium it requires for hydrate-phase development.

Each parameter is declared in the manufacturing-attestation lineage record so that the cured composite's preserved porosity can be traced to a documented operating point. The architecture admits parameter values within the declared ranges as in-scope of the preservation primitive; values outside the ranges are admitted as alternative embodiments only when accompanied by a verification result demonstrating equivalent porosity preservation.

Alternative Embodiments

Several alternative embodiments are contemplated. In a first alternative, the buffering admixture is replaced by a sacrificial additive that consumes hydroxide stoichiometrically during the critical pH window and is later consumed itself by ongoing hydration; this embodiment trades admixture cost against compositional simplicity. In a second alternative, the graphene is pre-encapsulated in porosity-preserving micro-aggregates (for example, lightweight ceramic or polymeric shells with engineered macroporosity) before incorporation, isolating the flakes from direct alkali exposure while admitting ion transport through the engineered shell porosity; this embodiment is preferred for binder systems whose pH cannot be moderated into the disclosed window without compromising binder development. In a third alternative, the cementitious binder itself is selected from a low-alkalinity family (for example, magnesium-phosphate cement, calcium-sulfoaluminate cement, or specifically formulated geopolymer) whose native pH lies within or below the disclosed window, eliminating the buffering admixture but requiring re-validation of the dispersant and calcium-sequestering parameters against the alternative chemistry.

A fourth alternative embodiment performs the cure under elevated humidity rather than under sealed conditions, reducing autogenous shrinkage stresses on the hierarchical pore network and admitting larger composite cross-sections. A fifth alternative substitutes a controlled-release dispersant that maintains stabilization through an extended hydration period, supporting later-age strength development without trading off early-age porosity preservation.

Composition With Substrate-Mode Storage Operation

The preservation primitive composes with the broader substrate-mode storage architecture by feeding verified BET-measured specific surface area, pore-size distribution, and pore-volume measurements into the credentialed admissibility profile that governs how the cured composite participates in storage operation. The lineage chain records the admixture identities and loadings, the cure-temperature profile, the buffering trajectory if instrumented, and the post-cure verification measurements, so that the energy-storage capacity available at deployment can be traced back to a documented preservation event. Downstream operating decisions, including charge-rate envelopes, depth-of-discharge limits, and end-of-life decommissioning, draw on the same lineage record.

Verification is performed by extracting cores from the cured composite, drying under conditions that do not themselves collapse the pore network, and measuring nitrogen adsorption isotherms from which BET specific surface area, BJH or DFT pore-size distributions, and total pore volumes are derived. The verification protocol is itself recited in the lineage record so that subsequent re-measurement against an independent core can re-establish the preserved-porosity claim.

Distinction From Prior Art

Prior art in graphene-cement composites generally treats the graphene as a strength-enhancing or conductivity-enhancing additive rather than as a storage substrate, and accordingly tolerates substantial surface-area loss during cure as long as bulk mechanical or electrical targets are met. Prior art in carbon-based supercapacitor electrodes preserves hierarchical porosity through electrolyte-formulation and binder selection within an electrochemical-cell envelope but does not address preservation through a structural cementitious cure. The disclosed primitive is distinct in that it preserves an FJH-derived multi-scale hierarchical porosity through a Portland-cement-class or geopolymer-class structural cure by simultaneous intervention on three degradation pathways, with verification measurements feeding a credentialed admissibility profile that governs storage operation.

Extended Considerations

Several extended considerations bear on the practical deployment of the preservation primitive. The first concerns the distinction among the three pore-size regimes. Micropores below approximately two nanometers contribute the dominant fraction of BET-measured specific surface area but are accessible only to small ions and only through tortuous paths; their preservation supports specific capacitance but not high charge-rate operation. Mesopores between approximately two and fifty nanometers contribute moderate surface area together with substantially shorter ion-transport paths; their preservation supports both capacitance and charge-rate operation. Macropores above approximately fifty nanometers contribute negligible surface area but provide the bulk-electrolyte highways that feed mesopore and micropore access during high-rate transients; their preservation supports rate capability and is the most fragile under the naive-mixing degradation pathways. The disclosed primitive preserves all three regimes because the ratio between them, not the absolute value of any one, governs the substrate-mode storage envelope.

The second consideration concerns the interaction between admixture chemistry and binder-system strength development. Buffering admixtures that suppress hydroxide concentration during early hydration may also retard the nucleation of strength-bearing hydrate phases, producing a cured composite whose porosity is well preserved but whose mechanical performance is degraded. The disclosed primitive contemplates this interaction by titrating the buffering admixture to act on the early-hydration window only, releasing pH constraint as the most degradation-vulnerable graphene chemistry stabilizes and the binder enters its principal hydration regime. The cure-temperature profile compresses this transition into a documented, repeatable trajectory rather than leaving it to ambient variability.

The third consideration concerns dispersant chemistry selection. Polycarboxylate-ether dispersants are widely used in cementitious systems and provide effective steric stabilization, but their adsorption on graphene surfaces competes with their adsorption on cement-particle surfaces, and the resulting equilibrium can starve either substrate of stabilization. The disclosed primitive admits dispersant selection from polycarboxylate-ether, naphthalene-sulfonate, lignosulfonate, and engineered block-copolymer families, with the dispersant-to-graphene mass ratio titrated against the specific surface area of the as-produced graphene so that adequate coverage of the graphene surface is maintained without depleting the bulk dispersant pool.

The fourth consideration concerns calcium-sequestering admixture selection. Phosphate-based sequestrants form sparingly soluble calcium phosphates that effectively remove free calcium but may also alter the calcium-silicate-hydrate phase composition. Polyacrylate-based sequestrants chelate calcium reversibly and release it as later-age hydration consumes the buffer, supporting full hydrate-phase development. The disclosed primitive admits both families and titrates loading against the free-calcium evolution profile of the specific binder, with the lineage record documenting the selection so that downstream verification can correlate preserved porosity with the chosen sequestering chemistry.

The fifth consideration concerns scale-up. Laboratory cure of small-cross-section samples under tightly controlled isothermal conditions reliably preserves hierarchical porosity within the disclosed parameter ranges, but field-scale composites face autogenous heating from binder hydration that can drive interior temperatures well above the disclosed 20 to 30 degree Celsius window. The disclosed primitive contemplates active thermal management of large pours, including pre-cooling of mix water, embedded cooling channels, or staged placement, with the thermal-management protocol recorded in the manufacturing-attestation lineage so that interior porosity preservation can be traced back to a documented thermal trajectory rather than assumed from surface temperature.

Disclosure Scope

The disclosure encompasses the mechanism, operating parameters, alternative embodiments, and verification regime described above. It is not limited to any particular cementitious binder family, any particular FJH precursor biomass, any particular admixture supplier, or any particular core-extraction protocol. The disclosure is intended to read on any implementation in which an engineered admixture chemistry and cure protocol preserve a multi-scale hierarchical porosity of biomass-derived turbostratic graphene through a cementitious setting reaction such that the cured composite retains the accessible surface area required for substrate-mode energy-storage operation. Specific values, ranges, and binder selections are recited as exemplary and not as limiting.