نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 گروه علوم و مهندسی کاغذ، دانشکده مهندسی چوب و کاغذ، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، ایران
2 دانشیار گروه صنایع خمیر و کاغذ، دانشگاه علوم کشاورزی و منابع طبیعی گرگان
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Objective: Paper and paperboard are widely used in the packaging industry due to their biodegradability, low cost, light weight, broad availability, ease of printing, flexibility, and relatively good mechanical strength. However, owing to its porous and hydrophilic nature, paper suffers from drawbacks such as poor resistance to the permeation of gases, moisture, and oils, as well as a loss of strength upon water absorption. These limitations restrict the use of paper in packaging applications. Given the extensive use of paper and paperboard in packaging for food, pharmaceuticals, and other products, this research aims to modify the paper surface using superhydrophobic materials. To achieve this, diatomaceous earth—a natural, readily available, and inexpensive material possessing inherent micro- and nano-scale surface roughness—was utilized as a substrate to induce superhydrophobicity in combination with Nanozycosil, a hydrophobic organosilane that reduces surface energy.
Materials and Mehtods: Handmade paper sheets were produced from bleached long-fiber pulp refined to a freeness of 400 ml CSF. Coating solutions were prepared by combining cationic starch, diatomaceous earth, and Nanozycosil at four levels: 0%, 5%, 7.5%, and 10% (based on the weight of the diatomaceous earth). These solutions were applied to the handmade paper sheets using a spray gun with a 1.3 mm nozzle diameter. The optical, strength, and barrier properties of both control and coated papers were measured in accordance with TAPPI standards. Contact angle analysis was performed using Image J software. Structural properties were examined via scanning electron microscopy (SEM) imaging and energy-dispersive X-ray spectroscopy (EDS) analysis. One-way analysis of variance (ANOVA) was used to assess the significance of the results, and Duncan's test was employed to group the means.
Results: As the percentage of Nanozycosil increased, strength properties—specifically the tensile strength index and bursting strength index—decreased compared to the control paper. Regarding optical properties, opacity increased while brightness decreased in the treated samples relative to the control. The coated paper demonstrated superior barrier performance—specifically regarding water absorption, oil resistance, and water vapor transmission rate—compared to the control paper. The water contact angle for the sample coated with 10% Nanozycosil reached 129 degrees, indicating significant hydrophobicity. Surface structure examination via scanning electron microscopy (SEM) and structural analysis using X-ray diffraction (XRD) confirmed the presence of diatomaceous earth particles in the coated samples.
Conclusion: By coating paper with diatomaceous earth and an organosilane compound—commercially known as NanoZykosil—using an appropriate formulation, papers with high hydrophobicity and good barrier properties were produced; these materials offer broad potential for use in packaging various products.
کلیدواژه‌ها [English]
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