Browsing by Author "Celik, N."

Now showing 1 - 7 of 7

Open Access
Machine learning-assisted pesticide detection on a flexible surface-enhanced raman scattering substrate prepared by silver nanoparticles
(American Chemical Society, 2022-09-12) Onses, M. Serdar; Ruzi, M.; Ceylan, A.; Sakir, M; Camdal, A.; Celik, N.; Sahin, F.
Access to clean water is a pressing challenge affecting millions of lives and the aquatic body of the Earth. Sensitive detection of pollutants such as pesticides is particularly important to address this challenge. This study reports eco-friendly preparation of the surface-enhanced Raman scattering (SERS) substrate for machine learning-assisted detection of pesticides in water. The proposed SERS platform was prepared on a copy paper by reducing a silver salt using the extract of a natural plant, Cedrus libani. The fabricated SERS platform was characterized in detail using scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The high-density formation of silver nanoparticles with an average diameter of 41 nm on the surface of the paper enabled detection of analytes with a nanomolar level sensitivity. This SERS capability was used to collect Raman signals of four different pesticides in water: myclobutanil, phosmet, thiram, and abamectin. Raman spectra of the pesticides are highly complex, challenging accurate determination of the pesticide type. To overcome this challenge and distinguish pesticides, machine learning (ML) approach was used. The ML-mediated detection of harmful pesticides on a versatile, green, and inexpensive SERS platform appears to be promising for environmental applications.
Open Access
Mechanochemical activation of siliconefor large-scale fabrication of anti-biofouling liquid-like surfaces
(American Chemical Society, 2023-11-13) Celik, N.; Sahin, F.; Ruzi, M.; Ceylan, A.; Butt, H. J.; Önses, Mustafa Serdar
Large-scalepreparationof liquid-likecoatingswithperfecttransparencyvia solventlessand room-temperatureprocessesusinglow-costand biocompatiblematerialsis oftremendousinterestfor a broadrangeof applications.Here,wepresenta mechanochemicalactivationstrategyfor solventlessgraftingof poly(dimethylsiloxane)(PDMS)ontoglass,siliconwafers,and ceramics.Activationis achievedvia ball millingPDMSwithoutusingany solventsor additivespriorto application.Ballmillingresultsin chainscissionand generationof free radicals,allowingroom-temperaturegraftingat durations≤1 h. Thedepositionof ball-milledPDMScan be facilitatedby brushingordrop-casting,enablinglarge-scaleapplications.Theresultingsurfacesfacilitatethe slidingof dropletsat angles<20°for liquidswith surfacetensionrangingfrom 22 to 73 mN/m.An importantapplicationfor publichealthis generatinganti-biofoulingcoatingson sanitaryware.For example,PDMS-graftedsurfacespreparedon a regular-sizetoiletbowlexhibita 105-fold decreasein theattachmentof bacteriafrom urine.Thesefindingshighlightthe significantpotentialof mechanochemicalprocessesfor the practicalpreparationof liquid-likesurfaces.
Open Access
Robust superhydrophobic fabrics by infusing structured polydimethylsiloxane films
(John Wiley & Sons, Inc., 2021-06-22) Celik, N.; Torun, I.; Ruzi, M.; Mustafa Serdar, Önses
Superhydrophobic coatings have large application potential in self-cleaning textiles. Low durability, high cost of fabrication, and environmental concerns over the usage of chemicals such as fluorocarbons limit the utilization of superhydrophobic coatings. This study reports a convenient and inexpensive approach to fabricate robust and fluorine-free superhydrophobic fabrics based on the transfer of structured polymer films and hydrophobic nanoparticles. In this approach, polydimethylsiloxane (PDMS) is infused between sheets of fabric and paper, followed by curing and removal of the paper. This process results in a fabric infused with PDMS whose structure is a negative replica of the paper surface. Then, hydrophobic nanoparticles are sprayed onto the structured PDMS side of the fabric. The infusion of PDMS and subsequent deposition of the hydrophobic nanoparticles enables strong bonding, as shown by the excellent solvent stability of the superhydrophobic fabric under ultrasonication. The proposed approach is universal in that it can be applied to almost any textiles, which upon coating, exhibited superhydrophobicity with a water contact angle of 172° and a sliding angle of 3°. Furthermore, the superhydrophobic fabric showed robust durability against water spray impact and mechanical bending where it can keep superhydrophobicity for at least 200 cycles of each test.
Open Access
Self-healing of biocompatible superhydrophobic coatings: the interplay of the size and loading of particles
(American Chemical Society, 2023-02-22) Celik, N.; Sahin, F.; Ozel, S. S.; Sezer, G.; Gunaltay, N.; Ruzi, M.; Önses, Mustafa Serdar
The broad application potential of superhydrophobic coatings is limited by the usage of environment-threatening materials and poor durability. The nature-inspired design and fabrication of self-healing coatings is a promising approach for addressing these issues. In this study, we report a fluorine-free and biocompatible superhydrophobic coating that can be thermally healed after abrasion. The coating is composed of silica nanoparticles and carnauba wax, and the self-healing is based on surface enrichment of wax in analogy to the wax secretion in plant leaves. The coating not only exhibits fast self-healing, just in 1 min under moderate heating, but also displays increased water repellency and thermal stability after healing. The rapid self-healing ability of the coating is attributed to the relatively low melting point of carnauba wax and its migration to the surface of the hydrophilic silica nanoparticles. The dependence of self-healing on the size and loading of particles provides insights into the process. Furthermore, the coating exhibits high levels of biocompatibility where the viability of fibroblast L929 cells was ∼90%. The presented approach and insights provide valuable guidelines in the design and fabrication of self-healing superhydrophobic coatings. © 2023 The Authors. Published by American Chemical Society.
Open Access
Superhydrophobic coatings for food packaging applications: A review
(Elsevier, 2022-06) Ruzi, M.; Celik, N.; Onses, M. Serdar
Food waste is a serious problem in our modern era, causing economic loss and exacerbating issues like hunger, environmental pollution, and water shortage. Residual food is one main culprit that can be easily eliminated by proper packaging. Advanced packaging techniques with self-cleaning and anti-fouling capabilities are critically important to tackle this issue. In this regard, superhydrophobic coatings are emerging as an innovative approach to address many critical issues in the food industry. Superhydrophobic coatings can prevent fouling and contamination of food packages. An additional capability is the minimization of food waste and improving consumer experience due to the easy sliding of food from the inner side of the package. In this article, we provide an overview of recent studies on the application of superhydrophobic coatings and surfaces for food packaging applications, with a focus on studies aimed at reducing residual food waste via superhydrophobic coatings prepared from edible, nontoxic, and ecofriendly materials.
Open Access
Transferring the structure of paper for mechanically durable superhydrophobic surfaces
(Elsevier, 2020-10-24) Torun, İ.; Celik, N.; Ruzi, M.; Önses, Mustafa Serdar
Solution-phase deposition of nanomaterials represents a highly promising technology with strong industrial application potential for the fabrication of superhydrophobic surfaces. An important barrier towards the adaptation of such materials and processes in a broad range of applications is the limited mechanical durability of the nanostructures. Herein, we present a universal solution to this challenge by benefiting from the unique micro-structure of paper. Our approach is based on transferring the structure of paper into a target material, to form a mechanical protection layer for nanomaterials that were deposited from solution-phase, i.e. spray-coating. We demonstrate this concept through the transfer of the structure of paper to a free-standing PDMS film using a simple molding process. Spraying a dispersion of alkyl-silane functionalized silica nanoparticles on the structured free-standing film results in a hierarchically structured superhydrophobic surface with a water contact angle of 175° ± 2° and a sliding angle <2° ± 1°. The fabricated superhydrophobic surface displays high levels of mechanical, chemical and thermal stability. The robust, inexpensive, scalable, flexible, and environmentally friendly nature of the presented approach may be a key enabler in superhydrophobic coating applications.
Open Access
Waxing the soot: Practical fabrication of all-organic superhydrophobic coatings from candle soot and carnauba wax
(Elsevier, 2021-02-04) Celik, N.; Celik, N. B.; Ruzi, M.; Önses, Mustafa Serdar
Commercial application of superhydrophobic coatings is hindered by insufficient durability and use of materials with high costs and limited availability. In this study, we report a robust water impact resistant all-organic superhydrophobic coating that is prepared from low-cost colloidal dispersion composed of carnauba wax and candle soot. The colloidal dispersion is stable and can be spray-coated onto virtually any surfaces. The coated surfaces exhibit superhydrophobicity with a water contact angle of 172° and sliding angle of 3°, and retain superhydrophobicity even after 400 cycles of continuous water spray with an impact pressure of 7.4 kPa. The synergetic combination of candle soot and carnauba wax, together with the deposition method, solvent used to disperse materials, and spray-coating distance are critically important for the superhydrophobicity and mechanical durability. The robustness of the coatings emerges from the two-tier hierarchical structure of the dried particles which is formed by evaporation induced self-assembly of wax molecules and candle soot nanoparticles. Applications in self-cleaning and oil/water separation are demonstrated, where a coated membrane can be continuously operated, solely driven by gravity, and can separate common organic liquids such as hexane and toluene from water with a separation efficiency of more than 90 % at a high flux of 1061 L / (m2 h).