Glycerol-Based Dendrimer Nanocomposite Film as a Tunable pH-Sensor for Food Packaging

Abstract

Large amounts of food are wasted during the food supply chain. This loss is in part due to consumer confusion over dates on food packages that can indicate a variety of quality indicators in the product (e.g., expiration date, “best by” date, “sell by” dates, etc.). To reduce this food loss, much research has been focused on the films that offer simple and easily manipulated indication systems to detect food spoilage. However, these materials are usually hydrophilic biopolymers that can detect the food spoilage in a wide pH range but do not provide highly sensitive real-time measurements. In this work, a glycerol-based nanocomposite core–shell latex film was synthesized to create a responsive packaging material that can provide real-time pH detection of food with high sensitivity. First, the pH-responsive dendrimer comonomer was synthesized from glycerol and diamine. Then, the nanoencapsulation polymerization process via miniemulsion was conducted to form a core–shell structure with tunable nanoshell thickness for a sensible pH-responsive release (<0.5 pH change). Next, the flexible film encapsulated a color-indicative dye that provided highly sensitive and visible color changes as both the pH dropped and the time elapsed in the food. This film also provided a barrier to water and heat and resisted deformation. Ultimately, this nanocomposite flexible film pending a pH sensor has the potential as an intelligent food packaging material for a universal, accurate, easy-to-use, and real-time food spoilage monitoring system to reduce food waste.

Monomers and Macromolecular Materials from Renewable Resources: State of the Art and Perspectives

“…Smart polymeric materials can be also produced from glycerol, which was the case of a pH-responsive dendrimer, prone to encapsulate or to release dyes depending on the pH. The synthesis consisted of the reaction of glycerol with acryloyl chloride, followed by the coupling of the ensuing glycerol triacrylate with ethylenediamine, the production of a glycerol-based dendrimer via free radical mini-emulsion polymerization, and film casting [ 115 ]. A new class of (meth)acrylate polymers was designed from glycerol ketals, whose syntheses were carried out with glycerol and ketones of varying specific molecular structures [ 116 ].…”

An Integrated Food Freshness Sensor Array System Augmented by a Metal–Organic Framework Mixed-Matrix Membrane and Deep Learning

“…Considering the robust water stability of UiO-66 NPs, the MOF MMM intelligent packaging film had a practical acceptable swelling ratio. 15 Furthermore, the solubility of the different systems was also tested. For the UiO-66-OH/PVA system, the supernatant had no visible color and negligible absorbance at 580 nm, whereas NR@PVA showed a red supernatant.…”

“…Each membrane was removed from the water and weighed on a regular basis until a consistent membrane weight ( M swollen ) was achieved, indicating that equilibrium had been established. The swelling index of films or water uptake was determined by eq …”

“…The membrane samples were then removed, washed, and dried in an oven at 100 °C until they reached a consistent weight (W 0 ). Membrane solubility was determined by eq 3 15 i k j j j j j y plastic box to replicate store storage conditions. Each package has one sensor array affixed to the inside of the box.…”

Chromophoric Dendrimer-Based Materials: An Overview of Holistic-Integrated Molecular Systems for Fluorescence Resonance Energy Transfer (FRET) Phenomenon

“…This is the case already described for biological systems (e.g., mitochondria, the photosynthetic system). Other comparatively less structurally complex but sophisticated artificial systems are abundantly reported in the literature, such as photoelectrochemical systems [58], sensors [59], semiconductors [60], and devices for solar cells [61], among others (Figure 5).…”