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At Chibio Biotech, we can provide Acid-soluble mushroom or aspergillus niger chitosan with viscosity: 200cps, 400cps, 600cps, 800cps, 1000cps. 

A. About Viscosity:

For making thin films, the best choice among the acid-soluble chitosan options (200cps, 400cps, 600cps, 800cps, 1000cps) depends on the desired mechanical properties, such as tensile strength, flexibility, and film-forming ability.

Comparison of Different Viscosity Grades for Thin Films

Chitosan Viscosity	Film Strength	Film Flexibility	Film Thickness	Transparency
200cps (Low)	Weak	Very flexible	Thin	High
400cps	Moderate	Flexible	Thin to Medium	High
600cps	Good	Balanced	Medium	Moderate
800cps	Strong	Slightly less flexible	Medium to Thick	Moderate
1000cps (High)	Very strong	Less flexible	Thick	Slightly opaque

Best Choice for Thin Films:

• For strong, durable films: 800cps or 1000cps (higher viscosity = higher molecular weight = stronger films).
• For balanced strength & flexibility: 600cps (good compromise between strength and flexibility).
• For ultra-thin, highly transparent films: 400cps (lower viscosity = better film clarity and softness).
• For soft, highly flexible films: 200cps (but may be too weak for structural applications).

Recommendation:

• If high tensile strength is needed → 1000cps.
• If good strength + flexibility is needed → 600-800cps.
• If very thin & transparent films are needed → 200cps, or 400cps.

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B. About the source: 

Considering mushroom chitosan and Aspergillus Niger chitosan have the same degree of deacetylation (DD), purity, molecular weight, cost, and structural composition, then their film-forming properties should be very similar. However, the source of chitosan (mushroom vs. Aspergillus Niger) may still have minor differences in performance due to:

1. Impurities and Trace Components

• Mushroom Chitosan: May contain small amounts of polysaccharides (e.g., β-glucans) from the fungal cell wall, which can slightly enhance film flexibility.
• Aspergillus Niger Chitosan: Typically more purified, leading to slightly stronger films but potentially less flexible.

2. Solubility and Film Uniformity

• Mushroom Chitosan: Often slightly more soluble in acidic solutions, which could lead to better film uniformity.
• Aspergillus Niger Chitosan: Similar solubility, but may have better consistency in film thickness due to fewer polysaccharide impurities.

3. Film Strength vs. Flexibility

Property	Mushroom Chitosan	Aspergillus Niger Chitosan
Tensile Strength	Slightly lower	Slightly higher
Flexibility	Better	Slightly less flexible
Transparency	High	High
Water Absorption	Slightly higher	Slightly lower

Which Source is Better for Thin Film?

• If you need higher flexibility → Mushroom Chitosan may be slightly better.
• If you need stronger, more rigid films → Aspergillus Niger Chitosan may be preferable.
• If both have identical properties, the choice may depend on availability, or regulatory considerations in specific applications.