Primary surface measurement reported
The study reports water contact angle (WCA) as a surface-wetting metric for the optimized SCR film.
Client Citation Analysis
Biodegradable films from soyhull cellulosic residue with UV protection and antioxidant properties improve the shelf-life of post-harvested raspberries
This study develops and characterizes an optimized soyhull cellulosic residue (SCR) biodegradable film and reports film surface wettability via water contact angle measured on the film surface.
At-a-Glance Summary
Dropometer attribution in the paper
The paper attributes sessile-drop water contact angle measurement to a “Dropometer (Droplet Lab, Canada)”, using smartphone image capture and sessile drop software to calculate WCA.
How the surface-tension / contact-angle data were used in the study
WCA is used as the study’s quantitative indicator of film surface hydrophobicity/wettability for the optimized film, and is discussed using a hydrophilic/hydrophobic interpretation threshold alongside comparisons to other film types cited in the discussion.
Replication / reliability statement
An average value from triplicate measurements is reported.
Paper Details
Title
Biodegradable films from soyhull cellulosic residue with UV protection and antioxidant properties improve the shelf-life of post-harvested raspberries
Authors
Sumi Regmi; Srinivas Janaswamy
Journal
Food Chemistry
Year
2024
Volume
460
Pages / Article
140672
License
© 2024 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
18.3
Scopus metrics (Elsevier / Scopus rating 2024)
Scopus metrics (Elsevier / Scopus rating 2024)
CiteScore subject ranks (CiteScore 2024)
- Q1 - Chemistry - Analytical Chemistry (3/160)
- Q1 - Agricultural and Biological Sciences - Food Science (10/404)
2.153
Scopus metrics (Elsevier / Scopus rating 2024)
1.952
Scopus metrics (Elsevier / Scopus rating 2024)
9.8
Journal Impact Factor (Clarivate JCR)
What Was Measured
Primary surface / interfacial measurement
Water contact angle (WCA) was measured on the film surface and reported as a wettability/hydrophobicity indicator for the optimized SCR film.
Supporting measurements
The optimized film is characterized with mechanical properties (tensile strength and elongation at break), water vapor permeability, optical behavior (UV/visible/IR transmittance and transparency), and additional film property measurements that contextualize packaging performance in the study.
Water contact angle
Dropometer (Droplet Lab, Canada)
Film tensile properties (TS, EB)
Texture Analyzer from Stable Micro Systems (Model TA-HD plus; serial no: 5529)
Film color
Nix color sensor Pro 2 (Model no: NIXPRO002, Canada)
Film thickness
digital Vernier caliper (RexBeti, China)
UV blocking / transparency (transmittance)
UV–Vis spectrophotometer (VWR International, USA, Model no: UV-1600PC, 10037–436)
FTIR spectroscopy
FTIR spectrophotometer Spectrum 100 from PerkinElmer
Experimental design / statistics
Design Expert 13 (Trial version); R software (RStudio 2022.07.01); Microsoft Excel for Mac (version 16.80) Solver add-ins
Role of the Dropometer
The study uses the Dropometer to measure sessile-drop water contact angle on the film surface: the film is placed on the instrument mount, a water droplet is deposited on the surface, the droplet is imaged using a smartphone interfaced with the equipment, and sessile drop software is used to calculate the water contact angle.
In the Results/Discussion, the reported WCA is interpreted as a wettability/hydrophobicity descriptor for the optimized film and is discussed using a stated hydrophilic/hydrophobic threshold and literature comparisons.
Bring This Measurement Into Your Lab
If you need water contact angle on biodegradable or bio-based films, we can show you the same sessile drop workflow on your samples.
Key Findings
Optimized film wettability quantified by WCA
The optimized SCR film is reported with a water contact angle of 72.6°, presented as the film’s “hydrophobicity” metric in the abstract and as the WCA result in the wettability section.
Paper-stated hydrophilic/hydrophobic interpretation
The authors state that a WCA below 90° indicates a hydrophilic material and a WCA above 90° indicates hydrophobic behavior, using this criterion to interpret the film’s surface.
Figure-based presentation of the contact-angle result
The WCA is visually presented as a sessile droplet image with tangent construction in Fig. 2f, where the film is described as hydrophilic with a low water contact angle.
Comparator reference discussed in the WCA section
The discussion cites a low-density polyethylene film WCA of 98.6° as a hydrophobic reference point in contrast to the optimized SCR film’s WCA.
Figures & Visuals
What it shows
This figure compiles the optimized film’s characterization outputs and includes the water contact angle panel (2f) alongside optical, water-uptake, and biodegradation visuals.
What it shows
This panel shows the sessile droplet on the film surface with tangent construction and labels the reported WCA = 72.6°.
Why It Matters
In the context of developing soyhull cellulosic residue-based biodegradable films for post-harvest raspberry packaging, the paper uses water contact angle as a direct, quantitative descriptor of the optimized film’s surface wettability/hydrophobicity.
The Dropometer-based WCA result is reported alongside the study’s broader characterization set (mechanical, barrier, optical, and shelf-life outcomes) to describe the optimized film’s surface interaction with water.
Expert Perspective
Practical Takeaways
Sessile-drop WCA workflow
The paper’s Dropometer workflow is described as mounting the film, placing a water droplet, capturing a smartphone image, and calculating WCA using sessile drop software.
Reported wettability value
The optimized SCR film is reported with a water contact angle of 72.6°.
Interpretation threshold used
The authors use a 90° cutoff to classify surfaces as hydrophilic (below 90°) or hydrophobic (above 90°).
Figure-ready WCA visual
The contact-angle result is presented as a droplet image with tangent construction in Fig. 2f, aligned with the numeric WCA value.
Contextual comparison provided
The discussion references a low-density polyethylene film WCA value (98.6°) as a hydrophobic comparator when discussing the optimized SCR film’s WCA.
Frequently Asked Questions
What did the Dropometer measure in this study?
The authors used a Dropometer (Droplet Lab, Canada) to measure the water contact angle on the optimized soyhull cellulosic residue film. The film was placed on the instrument mount, a water droplet was added, the droplet was imaged with a smartphone interfaced with the equipment, and sessile drop software calculated the angle.
What water contact angle did the optimized film show?
The paper reports a water contact angle of 72.6° for the optimized film (Fig. 2f), and states that reported values are averages of triplicate measurements. Using the 90° criterion they describe, the authors classify the film as hydrophilic and note that the value compares well with other natural polymer films, while a low density polyethylene film is cited at 98.6°.
Does the paper report contact angles for other formulations or over time?
The paper reports the water contact angle for the optimized film only, as a single static value without a stated spread, and does not report advancing, receding or time dependent angles. The film's interaction with water over time is covered by separate water absorption, solubility and water vapor permeability measurements.