Work

Cleaning the “silver mirror” with a triethanolamine-based strategy for black-and-white silver salt negatives

Year: 2026

Type: article

Abstract: It is well-known that black -and-white silver salt negative films are prone to “silver mirror” phenomenon, which diminishes image quality and imparts a metallic sheen to the surface. This study developed an efficient cleaning system based on isomeric alcohol ethoxylates eight (TO-8)/ Triethanolamine (TEA) (4:96, v/v) to address the “silver mirror” phenomenon. Through systematic screening and performance optimization, the cleaning agent effectively removed Ag2S particles after 180 minutes of immersion, significantly improving the optical properties and surface morphology of the films without compromising their mechanical strength. XPS and ATR-FTIR analyses confirmed the complete removal of Ag2S and revealed an increase in β-sheet content within the gelatin structure, which reduced the binding affinity to Ag2S and facilitated particle release. Grayscale analysis demonstrated notable recovery of image details and overall enhancement in image quality. The proposed method offers a safe, reliable, and operator-friendly cleaning strategy for the preservation of silver gelatine photographic heritage.

Source: npj Heritage Science

DOI: 10.1038/s40494-026-02466-y