Simple preparation of novel photochromic polyvinyl alcohol/carboxymethyl cellulose security barcode incorporated with lanthanide‐doped aluminate for anticounterfeiting applications

Abstract

Forgery and low-quality products pose a danger to society. Therefore, there are increasing demands for the production of easy-to-recognize and difficult-to-copy anticounterfeiting materials. Products with smart photochromic and fluorescence properties can change colour and emission spectra responding to a light source. In this context, we devised a straightforward preparation of a luminescent polyvinyl alcohol/carboxymethyl cellulose (PVA/CMC) nanocomposite to function as a transparent labelling film. The lanthanide-doped aluminate (LdA) was prepared in the nanoparticle form to indicate diameters of 35-115 nm. Different ratios of the LdA were physically dispersed in the PVA/CMC nanocomposite label film to provide photochromic, ultraviolet protection, antimicrobial activity, and hydrophobic properties.Fluorescence peaks were detected at 365 and 519 nm to indicate a colour change to green. As a result of increasing the phosphor ratio, improved superhydrophobic activity was achieved as the contact angle was increased from 126.1 to 146.0 without affecting the film's original physical and mechanical properties. Both ultraviolet (UV) light protection and antibacterial activity were also investigated. The films showed a quick and reversible photochromic response without fatigue. The current strategy reported the development of a photochromic smart label that is transparent, cost effective, and flexible. As a result, numerous anticounterfeiting products can benefit from the current label for a better market. LdA-loaded PVA/CMC films demonstrated antibacterial activity between poor, good, very good, and outstanding as the percentage of LdA in the film matrix increased. The current film can be applied as a transparent photochromic security barcode for anticounterfeiting applications and smart packaging.

Recent advances in photoresponsive printing inks for security encoding applications

“…Using rare‐earth aluminate nanoparticles (35–115 nm), Alfi and coworkers [119] created a photochromic polyvinyl alcohol/carboxymethyl cellulose nanocomposite label. Smart packaging and product anticounterfeiting are only two of the many potential uses for the developed transparent photochromic film, antibacterial efficacy, superhydrophobicity, UV protection, and photostability.…”

Preparation of a Transparent Photoluminescent Self-Healable Smart Ink for a Dual-Mode Security Authentication

“…They do not suffer molecular structure-switching steric effects because their emission relies on electronic excitation and relaxation activities. This results in very stable and durable photochromism with efficient quantum yields. − Lanthanide-doped long-persistent photoluminescent nanomaterials have been reported as attractive photochromic compounds, such as CaAl 2 O 4 :Eu 2+ ,Nd 3+ and SrAl 2 O 4 :Eu 2+ ,Dy 3+ . , Recently, numerous lanthanide-doped phosphors of different colors have been reported, such as SrAl 2 O 4 :Eu 2+ ,Dy 3+ (green emitter), CaAl 2 O 4 :Eu 2+ ,Nd 3+ (blue emitter), and CaS:Eu 2+ ,Tm 3+ ,Ce 3+ (red emitter) . Luminescent inorganic pigments like lanthanide-doped strontium aluminates (LSAs) have displayed a critical role in the preparation of photochromic materials due to their rapid responsiveness and photostability .…”