1. Water Treatment: The Most Mature and Largest Application Field

• Industrial circulating cooling water: It prevents the deposition of calcium carbonate, calcium sulfate, and iron oxide scales on heat exchange surfaces, improving heat transfer efficiency and reducing equipment corrosion. Unlike traditional phosphonate inhibitors (which cause eutrophication), PASP does not pollute water bodies, making it widely used in power plants, steel mills, and chemical factories.

• Oilfield water treatment: In oil extraction, it stabilizes formation water and injection water, preventing scale buildup in oil wells and pipelines—avoiding blockages that reduce oil production. It also works well in high-temperature (up to 80°C) and high-salinity environments.

• Household water treatment: Added to water softeners or laundry detergents, it chelates hard water ions, enhancing detergent efficacy and preventing scale on washing machines or water heaters.

2. Daily Chemicals: A Green Alternative to Traditional Chelating Agents

• Detergents and cleansers: As a builder, it binds to Ca²⁺/Mg²⁺ in hard water, preventing them from reacting with surfactants (avoiding "soap scum") and boosting cleaning power. It is used in laundry detergents, dishwashing liquids, and bathroom cleaners.

• Cosmetics and personal care: In skin care products (e.g., lotions, creams) and shampoos, it acts as a metal ion stabilizer—preventing heavy metals (from raw materials or water) from oxidizing active ingredients (e.g., vitamins, plant extracts), thus extending product shelf life and reducing skin irritation.

• Oral care: Added to toothpaste, it inhibits the deposition of calcium phosphate (tooth tartar) on enamel, while its non-toxicity ensures safety even if ingested in small amounts.

3. Agriculture: Promoting Nutrient Absorption and Reducing Environmental Pollution

• Fertilizer synergists: Mixed with nitrogen, phosphorus, and potassium (NPK) fertilizers, it chelates trace elements (Fe, Zn, Mn) in soil—preventing them from being fixed by soil colloids (which makes nutrients unavailable to plants). This increases fertilizer utilization by 15–30%, reduces fertilizer runoff (avoiding soil and water eutrophication), and improves crop yield/quality (e.g., enhancing fruit sugar content in tomatoes or strawberries).

• Soil conditioners: In saline-alkali soils, it binds excess Na⁺ and improves soil structure, reducing salt damage to crop roots and promoting root growth.

• Plant growth regulators: Dilute PASP solutions sprayed on leaves can enhance photosynthesis and stress resistance (e.g., drought, cold) in crops like wheat and rice.

4. Biomedicine: Emerging Applications Driven by Biocompatibility

• Drug delivery systems: Modified PASP (e.g., grafted with targeting molecules) can be made into microspheres or hydrogels to encapsulate drugs (e.g., anticancer drugs). It controls drug release at specific sites (reducing side effects) and degrades safely after release.

• Tissue engineering scaffolds: Cross-linked PASP hydrogels mimic the extracellular matrix, providing a supportive structure for cell growth. They are used in skin repair or bone tissue engineering—biodegrading gradually as new tissue forms.

• Dental materials: As a component of dental adhesives or filling materials, it improves biocompatibility with oral tissues and reduces inflammation risks.

5. Other Niche Applications

• Metallurgy and electroplating: In metal processing, it acts as a dispersant to prevent metal oxide particles from agglomerating, ensuring uniform plating and improving product surface quality.

• Textile industry: Added to dyeing baths, it chelates metal ions in water or dyes, preventing uneven dyeing and improving color fastness of fabrics.

Summary