Zinc-loaded gradient slow-release antibacterial quartz powder interior wall putty

Abstract

According to the efficient antibacterial quartz powder interior wall putty disclosed by the invention, quartz powder is modified through an innovative zinc ion-loaded surface modification technology, so that the 24-hour contact bacteriostasis rate of the putty to escherichia coli is gt; the content is 99.5%. The core breakthroughs comprise: (1) a zinc ion gradient slow-release carrier technology; (2) quartz powder lattice directional etching process; and (3) an antibacterial-mechanical property synergistic regulation system. On the premise of keeping the standard construction performance, the antibacterial durability of the product is improved by 300% (the accelerated aging test period is greater than or equal to 5 years), and the heavy metal precipitation amount is lower than the national standard limit value by 50%.

Description

Technical Field

[0001] This invention relates to the field of building decoration materials, specifically a zinc-ion-modified quartz powder interior wall putty with long-lasting antibacterial function. This invention discloses a highly efficient antibacterial quartz powder interior wall putty, which modifies quartz powder through an innovative zinc-ion-modified surface technology, achieving a 24-hour contact inhibition rate of >99.5% against Escherichia coli. Key breakthroughs include: ① zinc ion gradient slow-release carrier technology; ② quartz powder lattice directional etching process; ③ a synergistic regulation system for antibacterial and mechanical properties. While maintaining standard construction performance, the product achieves a 300% improvement in antibacterial durability (accelerated aging test cycle ≥5 years), and heavy metal leaching is less than 50% of the national standard limit. Background of the Invention

[0002] While existing technologies have attempted to load copper-bearing quartz powder, there is a risk of excessive metal precipitation (Cu). 2+ Release rate > 5 μg / cm 2 ·d)

[0003] With the increasing standards of public health and safety, the antibacterial properties of interior wall materials have become a mandatory requirement in medical, educational, and catering settings. According to WHO statistics (2024), approximately 23% of hospital-acquired infections (HAIs) originate from the transmission of pathogens from environmental surfaces, with *E. coli* and *S. aureus* being the main pathogens. Traditional antibacterial putty faces three major technological constraints:

[0004] 1. The fundamental contradiction between antibacterial durability and environmental safety

[0005] Organic antibacterial systems (such as quaternary ammonium salts and chlorophenols):

[0006] Its antibacterial mechanism relies on molecular chain disruption of cell membranes, but it is easily degraded by ultraviolet radiation and oxidation. Experiments show (GB / T 30706-2014 Accelerated Aging):

[0007] The antibacterial rate of quaternary ammonium salt modified putty decreased to 68±7% after 2 years.

[0008] The degradation products produce drug-resistant bacteria (mecA gene expression increased 15-fold).

[0009] Inorganic silver ion systems, while possessing broad-spectrum antibacterial properties, have two major drawbacks:

[0010] Economic considerations: When the silver content is ≥800ppm, the cost increases by ¥350-600 / ton (accounting for 32-45% of the raw material cost).

[0011] Ecotoxicity: Silver ion release > 2.0 μg / cm³ 2•d (exceeding the GB 18582 limit by 33%), with an LC50 of only 0.12 mg / L for aquatic organisms.

[0012] 2. Physical limitations that cause antibacterial failure in dark environments

[0013] Photocatalytic materials (such as nano-TiO2) require ultraviolet light excitation to generate ·OH free radicals, but this is not feasible in indoor environments with illuminance ≤300 lux.

[0014] Antibacterial efficiency decreased by >40% (compared to UV irradiation).

[0015] The actual antibacterial rate is only 82-86%.

[0016] Existing improvement solutions, such as using tungsten doping to enhance visible light response, have resulted in a significant cost increase of ¥420 / ton and the presence of photocorrosion issues.

[0017] 3. Irreversible damage to mechanical properties

[0018] High levels of antibacterial agents (>10wt%) lead to deterioration of the putty structure:

[0019] Antibacterial agent types Compressive strength (MPa) Shrinkage rate (%) Bond strength to substrate (MPa) No additions 0.72±0.03 0.08 0.65±0.04 8% Nano ZnO 0.51±0.05 0.21 0.42±0.06 10% silver-loaded zeolite 0.48±0.04 0.19 0.38±0.05

[0020] This strength loss stems from the interfacial incompatibility between the antibacterial agent and the matrix, which induces microcracks under drying stress (SEM showed a crack density > 15 cracks / mm).

[0021] 4. Existing technological attempts and legacy issues

[0022] A recently proposed copper-loaded quartz powder technology, while increasing the antibacterial rate to 97%, has raised new problems:

[0023] Excessive metal precipitation: Cu 2+ Release amount reached 5.3 μg / cm³ 2 ·d (exceeding national standard by 253%)

[0024] Color pollution: Copper ion oxidation causes the wall surface to turn green (ΔE>8, clearly visible to the naked eye).

[0025] Although the zinc-loaded zirconium phosphate system controlled the release rate to 1.2 μg / cm³, 2 ·d, but the zinc loading is only 4.7wt%, and the antibacterial rate is only 41.3%.

[0026] Industry Technology Requirements Map

[0027] Long-lasting antibacterial effect (>5 years)

[0028] │

[0029] ├──Environmental safety (heavy metals / VOCs meet standards)

[0030] │

[0031] ├──Suitable for all lighting conditions (including dark environments)

[0032] │

[0033] └── Mechanical properties maintained (compressive strength ≥ 0.7 MPa)

[0034] │

[0035] └── Costs are controllable (premium < 20%)

[0036] A 2025 industry survey report by the China Building Materials Association shows that the technology gap rate meeting all needs reached 98.6%.

[0037] Technological Evolution

[0038] [Ordinary calcium carbonate putty] --> [Organic antibacterial agent added] - [Nano silver composite system] --> [Photocatalytic material] --> E [Metal ion carrier] --> Technical bottleneck --> [Zinc-loaded gradient slow-release system of this invention]

[0039] See appendix for details Figure 5

[0040] Purpose of the invention

[0041] 1. Resolving the conflict between antibacterial durability and environmental safety

[0042] 2. Overcoming the limitations of antibacterial efficiency in dark environments

[0043] 3. Achieve a cost reduction of over 40% for antibacterial agents.

[0044] 4. Ensure the putty layer strength is ≥0.8MPa (national standard 0.6MPa).

[0045] Technical breakthrough of the present invention

[0046] Against this backdrop, this invention pioneers a zinc ion-modified quartz powder synergistic system, through three core innovations:

[0047] 1. Gradient-release carriers resolve the conflict between persistence and safety.

[0048] 2. Lattice-oriented etching achieves high zinc loading without strength loss

[0049] 3. CNC-Zn 2+ Coordination networks simultaneously enhance antibacterial and mechanical properties

[0050] While ensuring a comprehensive cost of ≤¥1,200 / ton, we have broken through the technical limits of antibacterial rate >99.5% and compressive strength >0.9MPa. Summary of the Invention

[0051] I. Core Innovative Technologies

[0052] 1. Zinc ion gradient sustained-release carrier technology

[0053] Using SiO2-ZnO core-shell structure ( Figure 1 By regulating the distribution of mesopores in the shell (pore size 5-20 nm), zinc ions can be released on demand.

[0054] High humidity environment: Pore expansion accelerates zinc release

[0055] Dry environment: pore shrinkage retains residue

[0056] Carrier structure design principles

[0057] The core of this technology lies in constructing a core-shell structure carrier with environmentally responsive characteristics. Using high-purity quartz powder (SiO2 content ≥ 99.2%) as the core, a zinc oxide (ZnO) composite shell is grown on its surface via a sol-gel method. This shell is not a homogeneous layer, but rather a mesoporous structure with a gradient thickness (shell thickness range: 80-200 nm) formed by controlling the hydrolysis-condensation reaction rate. This design achieves two main functions:

[0058] Pore ​​size distribution with denser inner layers and sparser outer layers: the pore size is smaller in the shell layer near the quartz core (5-8 nm) and larger in the outer layer (15-20 nm), forming a diffusion barrier gradient.

[0059] Differential loading of zinc ions: inner layer loaded with stable-state zinc ions (Zn) 2+ -SiO2 bonding), outer layer loaded with free zinc ions (Zn) 2+ -OH- adsorption)

[0060] 1.2 Humidity Response Release Mechanism

[0061] The carrier release behavior is regulated by ambient humidity, and its kinetics follow a modified model of Fick's second diffusion law:

[0062]

[0063] Where Deff is the effective diffusion coefficient, which has an exponential relationship with relative humidity (RH):

[0064] D eff =D0·e k·RH

[0065] (D0=2.3×10 -14 m 2 / s, k=0.032)

[0066] When the ambient humidity is greater than 65% (common in humid environments), water molecules penetrate into the mesoporous channels, causing the shell to swell and the pore size to increase by 30%-50%, accelerating the diffusion of free zinc ions in the outer layer; when the humidity is less than 40%, the shell contracts and locks in the inner zinc ions, achieving intelligent regulation of release on demand.

[0067] 1.3 Slow-release kinetic characteristics

[0068] The zinc ion release curve was determined by inductively coupled plasma mass spectrometry (ICP-MS). Figure 2 It was found that it exhibits three-stage characteristics:

[0069] 1. Burst release period (0-24h): Rapid release of free zinc from the surface, reaching a peak concentration of 1.8 μg / cm³. 2

[0070] 2. Stable release period (24h-30d): Zinc ions in the outer inner layer of the critical region can be continuously released through mesoporous channels at a constant rate of 0.22μg / cm³. 2 ·d

[0071] 3. Residual maintenance period (>30 days): Bound zinc is released through ion exchange upon microbial contact, maintaining a concentration >0.05 μg / cm³. 2

[0072] This kinetic characteristic allows the putty coating to maintain an effective zinc ion concentration of ≥0.7 μg / cm³ after 180 days in an accelerated aging test (85% RH / 45℃). 2 It meets the need for long-lasting antibacterial effects.

[0073] 1.4 Security Control Mechanism

[0074] To prevent excessive release of zinc ions, a zirconium phosphate (ZrP) buffer layer is incorporated into the support design:

[0075] When local Zn 2+ Concentration > 1.2 μg / cm³ 2 At that time, ZrP adsorbed excess zinc ions through ion exchange (adsorption capacity up to 45 mg / g).

[0076] Environment Zn 2+ As the concentration decreases, ZrP gradually releases reserve ions.

[0077] This mechanism keeps the zinc ion release level consistently between 0.6 and 1.0 μg / cm³. 2 ·d (National standard limit 1.5 μg / cm³) 2 •d) According to GB 18582-2020 testing, the cumulative release over 28 days only reached 32% of the national standard allowable value.

[0078] Technical verification data

[0079] Test conditions <![CDATA[Zinc release rate (μg / cm 2 ·d)]]> Antibacterial rate maintenance value initial state 1.78±0.21 99.82％ 30 days (normal environment) 0.85±0.09 99.74％ 180 days (accelerated aging) 0.71±0.07 99.41％

[0080] 1.5 Advantages compared with existing technologies

[0081] Traditional zinc loading technologies (such as physically mixed ZnO powder) have two major drawbacks:

[0082] 1. Uncontrollable release: Initial 24-hour release > 3 μg / cm³ 2 (Exceeds safety limit by 100%)

[0083] 2. Poor durability: Release rate decays to 0.2 μg / cm³ after 30 days. 2 The following (antibacterial rate <85%)

[0084] This technology achieves the following through gradient shell design and intelligent response mechanism:

[0085] Precise release control: Release rate increased to 1.5 μg / cm³ in humid environments (RH > 80%). 2 •d, in a dry environment (RH < 40%), the concentration decreased to 0.3 μg / cm³. 2 ·d

[0086] Extended effective lifespan: 5-year predicted antibacterial rate >99% (accelerated calculation based on the Arrhenius model).

[0087] The mechanism of this technology has been verified through molecular dynamics simulations: when water molecules permeate the mesopores, Zn... 2+ -O bond length is determined by Extend to The binding energy is reduced by 28.7 kJ / mol, which promotes the removal of zinc ions from the support surface.

[0088] 2. Quartz powder lattice directional etching process

[0089] A micron-scale pit array was constructed on the surface of quartz powder (200 mesh) using a mixed HF / NH4F etching solution (concentration ratio 1:3), increasing the specific surface area to 8.5 m². 2 / g (original powder 0.7m) 2 / g), with a zinc ion loading of 12.3wt%.

[0090] 2.1 Etching Mechanism and Chemical Basis

[0091] The essence of this process is to achieve crystal surface reconstruction through fluoride-mediated selective breaking of silicon-oxygen bonds. In the mixed etching system composed of hydrofluoric acid (HF) and ammonium fluoride (NH4F), a two-stage reaction occurs:

[0092] 1. Primary etching: F- atoms generated by HF dissociation attack the Si-O-Si bonds on the quartz surface, forming soluble [SiF6].2- Complex

[0093] SiO2 + 6HF → H2SiF6 + 2H2O

[0094] 2. Secondary regulation: NH4 + As a buffer, the reaction rate is controlled by forming a (NH4)2SiF6 precipitate layer to prevent over-etching.

[0095] H2SiF6+2NH 4+ -(NH4)2SiF6↓+2H +

[0096] The HF / NH4F concentration ratio in the mixed solution is strictly controlled at 1:3 (v / v). This ratio keeps the solution pH stable at 2.8-3.2, ensuring a balance between the etching rate (0.8 μm / h) and directionality control.

[0097] 2.2 Microstructure Construction Process

[0098] 2.2.1 Crystal plane selectivity

[0099] Quartz powder (200 mesh, D50 = 75 μm) exhibited significant anisotropy during the etching process:

[0100] (101) Crystal surface etching rate: 1.2 μm / h

[0101] (100) Crystal surface etching rate: 0.6 μm / h

[0102] This difference results in the formation of an array of pits with a depth of 0.8–1.5 μm on the crystal surface, with a pit density of 3.2 × 10⁻⁶. 4 pcs / mm 2 .

[0103] 2.2.2 Morphological Regulation Mechanism

[0104] Etching uniformity is improved by introducing ultrasonic cavitation effect (frequency 40kHz, power 300W):

[0105] The collapse of cavitation bubbles generates localized high pressure (>50 MPa), which promotes the penetration of the etching solution into the grain boundaries.

[0106] Microfluidization removes reaction products promptly, avoiding the masking effect.

[0107] Comparative experiments show that ultrasonic treatment increases the surface roughness (Ra) from 1.8 μm to 4.3 μm and the specific surface area by 12 times (BET test: 8.5 μm). 2 / g vs 0.7m 2 / g).

[0108] 2.3 Optimization of process parameters

[0109] Key control parameters were determined using the response surface methodology (RSM).

[0110] parameter optimal value Permissible fluctuation range Influence weight temperature 45±1℃ 40-50℃ 34.2％ Etching time 30±2min 25-35min 28.7％ solid-liquid ratio 1：10 1：8-1：12 22.1％ Ultrasonic power 300W 250-350W 15.0％

[0111] Exceeding the allowed range will result in:

[0112] Temperature > 50℃: Pits connect to form cracks (compressive strength ↓35%)

[0113] Time > 35 min: Surface powdering (specific surface area ↓40%)

[0114] 2.4 Structural Characterization and Functional Correlation

[0115] 2.4.1 Geometric characteristics of the pit

[0116] Laser confocal microscopy (CLSM) measurements show:

[0117] Diameter of the pit opening: 2.8 ± 0.7 μm

[0118] Aspect ratio: 0.53 ± 0.12

[0119] Sidewall inclination angle: 72±8°

[0120] 2.4.2 Zinc ion loading enhancement

[0121] Etched surfaces enhance zinc loading through two mechanisms:

[0122] 1. Physical anchoring: The concave structure enables Zn to be anchored. 2+ The adsorption site density increased to 8.3 × 10⁻⁶. 16 pcs / m 2 (Untreated surface: 2.1 × 10) 15 pcs / m 2 )

[0123] 2. Chemical bonding: The etched-exposed Si-OH groups react with APTES silane coupling agent to form ≡Si-O-Si(CH2)3NH2-Zn 2+ Bonded structure.

[0124] XPS analysis confirmed that the Zn surface after etching... 2+ The binding energy peak (1022.3 eV) intensity increased by 6.8 times, and the appearance of the N 1s peak (399.5 eV) confirmed the formation of amino coordination bonds.

[0125] 2.5 Comparison with traditional processes

[0126]

[0127]

[0128] Process validation data

[0129] Small-scale production testing (batch size 500kg):

[0130] Etching uniformity: The coefficient of variation of specific surface area for quartz powder with different particle sizes (45-150μm) is ≤7.3%.

[0131] Repeatability: Standard deviation of zinc loading for 5 consecutive batches σ = 0.21 wt%.

[0132] Environmental friendliness: The concentration of fluoride ions in the waste liquid was reduced to 8.2 mg / L after Ca(OH)2 precipitation treatment (national standard limit of 10 mg / L).

[0133] 3. Synergistic system of antibacterial and mechanical properties

[0134] Adding cellulose nanocrystals (CNC, 20 nm in diameter) treated with a silane coupling agent forms:

[0135] Quartz powder - Zn 2+

[0136] │

[0137] CNC cross-linked network → compressive strength increased by 40%

[0138] │

[0139] polymer emulsion

[0140] 3.1 Synergistic Mechanism

[0141] The core breakthrough of this system lies in solving the industry-wide problem of the mutual constraint between functionality and mechanical properties in antibacterial materials. By introducing cellulose nanocrystals (CNC) modified with γ-aminopropyltriethoxysilane (KH550), a three-dimensional organic-inorganic interpenetrating network is constructed between zinc-loaded quartz powder and polymer emulsion (VAE type). Its synergistic effect is manifested in:

[0142] Mechanical reinforcement: The silane coupling agent (≡Si-O-Cellulose) on the CNC surface forms hydrogen bonds with the hydroxyl groups of quartz powder (bond energy ≈25kJ / mol), while its nanofibers (diameter 20±3nm) are interwoven between latex particles to form a topologically entangled structure.

[0143] Antibacterial synergy: The amino group (-NH2) carried by CNC reacts with Zn 2+ Formation of coordinate bonds (Zn-N bond length) This increases the zinc ion distribution density by 40% and reduces the ion migration activation energy (from 58 kJ / mol to 42 kJ / mol).

[0144] 3.2 Functional Design of Key Components

[0145] 3.2.1 Cellulose nanocrystal modification

[0146] In-situ surface grafting method:

[0147] 1) Disperse CNC (83% crystallinity) derived from softwood pulp in an ethanol / water mixture (volume ratio 7:3).

[0148] 2) Add KH550 (8% of CNC mass) and react at 60℃ for 4 hours.

[0149] 3) After centrifugation and washing, amination-treated CNC was obtained (elemental analysis showed that the nitrogen content reached 3.1 wt%).

[0150] After modification, the Zeta potential of the CNC machine changes from -32mV to +18mV, ensuring that it can generate electrostatic attraction with the negatively charged zinc-loaded quartz powder (-25mV).

[0151] 3.2.2 Interface Bonding Structure

[0152] Confirmed by synchrotron X-ray absorption fine structure spectroscopy (XAFS) Figure 6 ):

[0153] Characteristic coordination peaks were found at the Zn K-edge (R-space). (location), corresponding to the Zn-ON coordination structure

[0154] Fourier transform intensity analysis shows that per mole of Zn 2+ On average, 1.2 amino nitrogen atoms are coordinated.

[0155] This bonding increases the interfacial bonding energy to 112 J / m. 2 (The unmodified system has only 68 J / m) 2 Molecular dynamics simulations have verified that fracture during tensile testing preferentially occurs within the CNC machined interior rather than at the interface.

[0156] 3.3 Dynamics of Multi-Level Structure Assembly

[0157] The putty curing process forms a four-layer ordered structure:

[0158] 1. Primary structure: Zinc-loaded quartz powder serves as a rigid framework (particle size D50 = 75 μm).

[0159] 2. Secondary structure: Amination CNC bridging of adjacent quartz particles (bridging length 0.8-1.5μm)

[0160] 3. Tertiary structure: VAE emulsion is formed in the gaps between CNC networks (film thickness approximately 200 nm).

[0161] 4. Quaternary structure: Zinc ions are enriched into antibacterial active sites at the CNC / emulsion interface (density up to 5.6 × 10⁻⁶). 14 pcs / cm 2 )

[0162] The formation of this structure is controlled by the coupling of evaporation rate and shear force:

[0163] Application and scraping stage (shear rate > 100s) -1 CNCs are oriented along the flow field direction.

[0164] Surface drying stage (water evaporation rate 0.8 g / m³) 2 •s): Capillary forces drive the emulsion to migrate towards the CNC / quartz interface.

[0165] 3.4 Performance Synergistic Improvement Verification

[0166] 3.4.1 Mechanical Properties

[0167] Performance parameters This system No CNC reference Improvement rate Compressive strength (MPa) 0.92±0.05 0.66±0.04 39.4％ Bond strength (MPa) 0.88±0.03 0.61±0.05 44.3％ Elastic modulus (GPa) 2.35±0.11 1.78±0.09 32.0％

[0168] Data was tested according to JC / T 298-2010 standard.

[0169] 3.4.2 Antibacterial properties

[0170] Improved contact efficiency: The microfiber network formed by CNC increases the probability of bacterial contact by 3.2 times (fluorescently labeled E. coli adhesion experiment).

[0171] Long-term mechanism: CNC / Zn 2+ The dissociation energy of the coordination bond (186 kJ / mol) is higher than that of simple physical adsorption (<50 kJ / mol), which extends the half-life of zinc ion release from 15 days to 48 days.

[0172] 3.5 Advantages compared to conventional systems

[0173]

[0174] 3.6 Key Points for Industrialization Implementation Control

[0175] 1. Dispersion process: Three-stage shear dispersion is adopted.

[0176] Low-speed mixing (500 rpm, 3 min): Premixed dry powder

[0177] High-speed dispersion (2000 rpm, 8 min): Add VAE emulsion

[0178] Ultrasonic treatment (40 kHz, 2 min): Depolymerization of CNC clusters

[0179] 2. Curing control: Construction environment requirements

[0180] Temperature: 5-35℃ (optimal 25℃)

[0181] Relative humidity: 40-70% (if outside this range, adjust the CNC addition amount by ±0.2%)

[0182] II. Key Performance Indicators

[0183] Test Project This invention National Standard Requirements Competitors (Silver Series) Antibacterial rate (24h) 99.82％ ≥90％ 98.75％ Antibacterial durability 5-year retention rate of 99% 2 years ≥ 85% 95% in 3 years Zinc ion release <![CDATA[0.8μg / cm 2 ·d]]> ≤1.5μg 2.3 μg of silver ions Bond strength 0.92MPa ≥0.6MPa 0.75MPa

[0184] originality

[0185] 1. Revolutionary antimicrobial carrier design

[0186] Originality: First construction of a SiO2-ZnO gradient core-shell structure ( Figure 7 This is achieved through a mesoporous shell thickness gradient (80-200 nm):

[0187] In high humidity environments (RH>80%), the zinc ion release rate increases to 1.5 μg / cm³. 2 •d (conventional carrier ≤0.4μg)

[0188] In a dry environment (RH < 40%), the release rate was self-inhibited to 0.3 μg / cm³. 2 •d (conventional vectors still >0.8μg)

[0189] Technical Comparison: Traditional zinc-loaded technologies (such as CN108456361A) use homogeneous coating and have a sluggish humidity response (response hysteresis > 12h), while the response time of this technology is < 15min (QCM-D in-situ monitoring data).

[0190] 2. Crystal Etching Orientation Control

[0191] Unique feature: The etching rate difference between the (101) and (100) crystal planes of quartz in the HF / NH4F system was discovered (1.2 vs 0.6 μm / h), and based on this, an ultrasonic cavitation-assisted etching process was developed.

[0192] By using cavitation microjets to directionally impact the (100) crystal plane, the aspect ratio of the pits was precisely controlled to be 0.53 ± 0.12.

[0193] Technical Comparison: Traditional acid etching methods can only produce disordered pores (aspect ratio fluctuating between 0.1 and 1.8), with poor zinc loading uniformity (CV > 35%).

[0194] 3. Antibacterial-mechanical synergistic mechanism

[0195] Unique feature: Revealing the amination of CNC-Zn 2+ Dual function of coordinate keys:

[0196] From a mechanical perspective: a covalent network ≡Si-O-Cellulose-NH-Zn-O-SiO2≡ is formed (bond energy 186 kJ / mol).

[0197] Antibacterial aspect: Reduces Zn 2+ The activation energy for migration is 16 kJ / mol (confirmed by DFT calculations).

[0198] Technology Comparison: Existing technologies add CNC only as a reinforcement phase and do not achieve functional synergy.

[0199] Beneficial effects

[0200] 1. Antibacterial properties break through industry limits

[0201]

[0202] Note: The calculation was accelerated using the Arrhenius model (equivalent to 5 years at 85℃ / 85%RH).

[0203] 2. Overall costs reduced by more than 40%

[0204] Raw material cost: Zinc replacing silver (unit antibacterial cost ¥0.18 / g vs ¥3.5 / g)

[0205] Construction cost: Drying time reduced to 28 minutes (competitors ≥ 45 minutes), construction period shortened by 37%.

[0206] Maintenance cost: 5 years maintenance-free (competitors require touch-up antibacterial coating every 2 years)

[0207] 3. Environmental safety standards are met.

[0208] Testing items Measured value Standard Limit Zinc ion release (cumulative over 28 days) <![CDATA[22.4μg / cm 2 ]]> <![CDATA[GB18582≤70μg / cm 2 ]]> VOC emissions (TVOC) <![CDATA[28μg / m 3 ]]> <![CDATA[ISO16000≤500μg / m 3 ]]> Ecotoxicity (EC50) >1000mg / L (non-toxic) OECD201 ≤ 100 mg / L

[0209] 4. Synergistic improvement of mechanical properties

[0210] ■ Compressive strength: 0.92MPa (national standard 0.6MPa) → Load-bearing capacity increased by 53%

[0211] ■ Crack resistance: No cracking below 0.5mm (competitor's product cracks below 0.3mm)

[0212] ■ Freeze-thaw resistance: Strength loss rate after -20℃ / 50 cycles <8% (National standard ≤15%)

[0213] 5. Adaptability to special scenarios

[0214] Extreme Environments Performance retention rate Competitor retention rate High salt spray along the coast (Cl-5000ppm) Antibacterial rate 98.7% 89.2％ Cold chain warehouse (5℃ / 95%RH) Bond strength 0.81 MPa 0.48MPa Hospital environment disinfection (hypochlorous acid wiping) No change in surface integrity Powdering rate >15%

[0215] 6. Diagram of generational technological differences

[0216] See appendix for details Figure 6

[0217] Industry verification data

[0218] Application in cell culture center (Xi'an XX Provincial Cell Bank): Total bacterial count on wall surface consistently <50 CFU / cm³ 2 (Ordinary antibacterial putty >500 CFU / cm³) 2 )

[0219] The technology has passed the scientific and technological achievement appraisal of Xi'an Cell Technology Association (Appraisal No.

[2025] 028), confirming that it "has reached the leading level in the field of antimicrobial functional materials". Detailed Implementation

[0220] Example 1: Preparation of modified quartz powder

[0221] 1. Take 1 kg of 200-mesh quartz powder, immerse it in a mixture of HF (5%) / NH4F (15%), and sonicate at 45℃ for 30 min.

[0222] 2. After washing with water until neutral, immerse in a ZnCl2 (0.5 mol / L) + APTES (3%) solution, pH = 8.5.

[0223] 3. Aging at 80℃ for 6 hours, followed by centrifugal drying to obtain zinc-loaded quartz powder (Zn content 11.8wt%).

[0224] Example 2: Putty Formula

[0225]

[0226] Example 3: Performance Verification

[0227] Antimicrobial testing: according to ISO 22196 standard

[0228] Escherichia coli ATCC 25922: Inhibition rate 99.82%

[0229] Staphylococcus aureus: Inhibition rate 99.76%

[0230] Accelerated aging: After 180 days of storage in an environment with 85% RH / 45℃, the antibacterial rate remains at 99.41%.

[0231] Application: Scraping is unobstructed; surface drying time is 45 minutes (at ambient temperature of 25°C and 65% RH).

[0232] The following three specific implementation cases, based on core technological innovations, cover raw material substitution, extreme environment adaptation, and low-cost application scenarios, and meet the requirements for full disclosure in patent implementation:

[0233] Example 4: Alternative to rice husk ash-based zinc-loaded quartz powder

[0234] Background: Developing utilization pathways for siliceous solid waste in regions where quartz raw materials are scarce.

[0235] step:

[0236] 1. Raw material processing:

[0237] Rice husk ash (SiO2 content 92.3%) was ball-milled to 300 mesh (D50 = 18μm).

[0238] Acid washing for impurity removal: Treatment with 5% oxalic acid solution at 60℃ for 2 hours to remove metal oxides.

[0239] 2. Etching modification:

[0240] Use an optimized etching solution (HF 4% + NH4F 10% + 0.1M citric acid).

[0241] Ultrasonic treatment at 40℃ for 40 minutes (power 250W)

[0242] 3. Zinc loading process:

[0243] Impregnation solution: ZnSO4 0.3M + silane coupling agent KH7922%

[0244] Load temperature 70℃, time 5h

[0245] Performance verification:

[0246]

[0247]

[0248] Example 5: Formula for High Humidity Environments

[0249] Background: Suitable for coastal areas and aquatic product processing plants with relative humidity > 85%.

[0250] Formula innovation:

[0251] Add hydrophobically modified halloysite nanotubes (HNT, 50 nm in diameter)

[0252] Modification method: Octadecyltrimethoxysilane vapor-phase grafting

[0253] Dosage: 1.2 servings

[0254] Adjust the ratio of zinc-loaded quartz powder to heavy calcium carbonate to 70:20 (to increase the proportion of antibacterial components).

[0255] Key processes:

[0256] 1. HNT pre-dispersion: After blending with VAE emulsion, sonicate (40kHz / 10min)

[0257] 2. Step-by-step mixing:

[0258] Dry powder mixing - adding emulsion + HNT premix - low speed stirring for 10 minutes - vacuum degassing

[0259] See attached diagram for details. Figure 7

[0260] Extreme environment testing (GB / T 1741-2020):

[0261] condition result Constant temperature and humidity (30℃ / 95%RH) for 28 days No mold growth, antibacterial rate maintained at 99.17%. Salt spray test (5% NaCl) 240h Bond strength retention rate: 91.3%

[0262] Example 6: Low-cost, fast-drying formulation

[0263] Objective: To meet the needs of cost-sensitive projects such as affordable housing (overall cost ≤ ¥800 / ton)

[0264] Technical approach:

[0265] 1. Zinc source substitution:

[0266] A ZnCl2-Zn(OH)2 composite zinc source (molar ratio 2:1) was used.

[0267] Cost is 42% lower than pure ZnCl2

[0268] 2. Packing material optimization:

[0269] The amount of zinc-loaded quartz powder added was reduced to 50 parts.

[0270] Add modified fly ash microspheres (30 parts, 200 mesh)

[0271] Preparation process:

[0272] Step 1: Apply the composite zinc source (Zn) 2+ A mixture of 0.4 mol / L total concentration and 1.5% APTES

[0273] Step 2: Impregnate fly ash microspheres in the above solution and react at 60℃ for 4 hours → to obtain zinc-loaded fly ash.

[0274] Step 3: Dry mix with the remaining components (total mixing time ≤ 8 min)

[0275] Balance between economy and performance:

[0276] parameter This embodiment Standard Implementation Examples Material cost (RMB / ton) 785 1120 Surface drying time (25℃) 28min 45min Antibacterial rate (24h) 98.05％ 99.82％ Crack resistance (0.5mm crack) No cracks No cracks

[0277] Supplementary Case Studies on Industrialization Verification

[0278] Example 7: Application of ship cabin interior walls

[0279] Scenario: Living quarters of a 100,000-ton cargo ship (high salt spray environment at sea)

[0280] Construction plan: Surface preparation: Sandblasting to remove rust, followed by epoxy primer application; putty thickness: 2mm (two coats). 18-month follow-up data:

[0281]

[0282]

[0283] Example 8: Cold Chain Warehouse Renovation

[0284] Environmental characteristics: Long-term 0-5℃ / 85%RH

[0285] Technical adjustments: Add 0.8 parts of a low-temperature curing agent (vinyltrimethoxysilane), increasing the CNC curing amount to 0.7 parts.

[0286] Effect:

[0287] Application at -5℃ can still achieve surface drying (time extended to 120 minutes).

[0288] No powdering after 50 freeze-thaw cycles (ASTM D6944 standard)

[0289] Example Design Logic Description

[0290] See attached diagram for details. Figure 8

[0291] Comparison of three cutting-edge technologies

[0292] Technical dimension This invention Traditional silver-based antibacterial Organic antibacterial agents Antibacterial mechanism Zinc ion membrane damage + ROS attack Silver ion contact sterilization Molecular chain penetration Dark environment efficiency Maintain 98%+ Dropped to 85% Failure Cost increment ¥15-20 / ton ¥200+ / ton ¥80-100 / ton Environmental safety No risk of heavy metal accumulation Silver ion ecotoxicity Drug-resistant bacteria

[0293] Industry value

[0294] This technology has been applied to the renovation project of a cell culture center (Xi'an XX Provincial Cell Bank): the total bacterial count on the wall surface has consistently been <50 CFU / cm³. 2 (Ordinary antibacterial putty >500 CFU / cm³) 2 This verified the engineering reliability of the technology. Attached Figure Description

[0295] Figure 1 Schematic diagram of SiO2-ZnO core-shell structure

[0296] Figure 2 Zinc ion release kinetic curve

[0297] Figure 3 Humidity-responsive release mechanism model

[0298] Figure 4 CNC-Zn 2+ Collaborative Enhancement Architecture

[0299] Figure 5 Technological Evolution

[0300] Figure 6 A diagram illustrating generational differences in technology.

[0301] Figure 7 Step-by-step mixing process

[0302] Figure 8 Example Design Logic Description

Claims

1. An antibacterial quartz powder interior wall putty, characterized in that... It contains the following components and parts by weight: 50-70 parts of zinc ion-modified quartz powder 20-35 parts of heavy calcium carbonate powder 5-10 parts redispersible latex powder 1-2 parts of hydroxypropyl methylcellulose Aminated cellulose nanocrystals, 0.3-0.8 parts Water-reducing agent 0.2-0.5 parts The zinc-loaded modified quartz powder has a zinc loading of 8-15 wt% and a 24-hour inhibition rate of >99.5% against Escherichia coli.

2. The zinc-loaded ion-modified quartz powder as described in claim 1, characterized in that: It has a SiO2-ZnO core-shell structure with a shell thickness of 80-200nm and a gradient distribution. The shell contains mesoporous channels with a pore size of 5-20nm. The outer surface of the shell is loaded with free zinc ions, and the inner layer is Zn. 2+ -SiO2 bonded zinc ions; The shell contains a zirconium phosphate buffer layer, and the zinc ion release is controlled at 0.6-1.0 μg / cm³. 2 ·d.

3. The method for preparing zinc ion-modified quartz powder as described in claim 2, characterized in that... include: a) Immerse 200-mesh quartz powder in a mixed etching solution of HF 4-6% / NH4F 12-18% and sonicate at 40-50℃ for 25-35 minutes; b) After washing with water, immerse in a solution containing 0.3-0.8 mol / L zinc salt and 1-5% silane coupling agent, pH=8.0-9.0; c) Aging at 70-85℃ for 4-8 hours, followed by centrifugal drying to obtain zinc-loaded quartz powder.

4. The aminated cellulose nanocrystals as described in claim 1, characterized in that: It is prepared by sulfuric acid hydrolysis of softwood pulp cellulose, with a diameter of 15-25 nm, and is surface-modified with γ-aminopropyltriethoxysilane. Its amino content is 2.8-3.5 wt%, and its Zeta potential is +15 to +25 mV; The coordinate bond length with zinc ions is The coordination number is 1.0-1.

5.

5. The antibacterial quartz powder interior wall putty as described in claim 1, characterized in that... Also includes: 0.5-1.5 parts of hydrophobically modified halloysite nanotubes, wherein the halloysite is grafted with octadecyltrimethoxysilane and has a contact angle >100°.

6. The application of the antibacterial quartz powder interior wall putty as described in claim 1 in a high humidity environment, characterized in that: When the relative humidity of the environment is >85%, the amount of zinc-loaded quartz powder added should be increased to 65-70 parts. The substrate should be pre-coated with epoxy primer, and the putty layer should be 1.5-2.0mm thick.

7. The method for preparing antibacterial quartz powder interior wall putty as described in claim 1, characterized in that: A three-stage dispersion process is adopted: Phase 1: Dry mix at 500-800 rpm for 3-5 minutes Second stage: After adding VAE emulsion, disperse at 2000-2500 rpm for 8-10 minutes. Third stage: 40kHz ultrasonic treatment for 1-3 minutes.

8. The antibacterial quartz powder interior wall putty as described in claim 1, characterized in that... The zinc-loaded ion-modified quartz powder can be replaced with zinc-loaded rice husk ash powder, wherein: Rice husk ash with SiO2 content >90% is ball-milled to 300 mesh after being purified with oxalic acid; The etching solution was adjusted to HF 3-5% + NH4F 8-12% + 0.05-0.15M citric acid.

9. The application of the product according to any one of claims 1-8 in a medical cleanroom, characterized in that: The total number of bacterial colonies on the wall surface is consistently <50 CFU / cm³ 2 It exhibits an inhibition rate of >99.2% against methicillin-resistant Staphylococcus aureus (MRSA). Basis for setting key numerical ranges: Zinc loading 8-15%: <8% insufficient antibacterial activity (<99%), >15% decreased strength (compressive strength <0.7MPa) CNC addition amount 0.3-0.8%: <0.3% synergistic failure (strength↑ <20%), >0.8% application sticking to the trowel.

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