On the distinct molecular architectures of dipping- and spray-LbL films containing lipid vesicles

Aoki, Pedro H.B.; Aléssio, Priscila; Volpati, Diogo; Paulovich, Fernando V.; Riul, Antonio; Oliveira, Osvaldo N.; Constantino, Carlos J. L.

doi:10.1016/j.msec.2014.04.067

Cited by 12 publications

(6 citation statements)

References 59 publications

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“…The most widely used method to analyze the data generated by sensors and biosensors is the principal component analysis (PCA; Gorban and others ). However, recently another technique, referred to as Sammon's mapping (Sammon ) has been increasingly used with better results in terms of distinguishability (Aoki and others , ; Rubira and others ). In this paper, the Sammon's mapping multidimensional projection technique was successfully used to DPV data analysis.…”

Section: Methodsmentioning

confidence: 99%

Layer‐by‐Layer Thin Film of Iron Phthalocyanine as a Simple and Fast Sensor for Polyphenol Determination in Tea Samples

Maximino

Martin

Paulovich

et al. 2016

Journal of Food Science

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Polyphenols have attracted attention due to their antioxidant capacity and beneficial effects to health. Therefore, fast, inexpensive, and efficient methods to discriminate and to quantify polyphenols are of interest for food industry. In this paper, Layer-by-Layer films of poly(allylamine hydrochloride) and iron tetrasulfonated phthalocyanine were employed as sensor for determination of polyphenols in green tea (camellia sinensis), and green and roasted mate teas (ilex paraguariensis). The polyphenol sensor was tested in catechol standard solution by differential pulse voltammetry (DPV), reaching a limit of detection of 1.76 × 10 mol/L. The determination of polyphenols in the tea samples was obtained by analytical curve and catechol standard addition using electrochemical techniques. Projection techniques (information visualization) were applied to the DPV results of the tea samples and a pattern of separation following the phenolic content was obtained. The results support the application of the sensor in fast classification of beverages according to their polyphenol content.

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Section: Methodsmentioning

confidence: 99%

Layer‐by‐Layer Thin Film of Iron Phthalocyanine as a Simple and Fast Sensor for Polyphenol Determination in Tea Samples

Maximino

Martin

Paulovich

et al. 2016

Journal of Food Science

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“…58,129,[131][132][133][134] Although these approaches can seem harsh, thermodynamically unstable but kinetically trapped systems, such as liposomes, can remain intact through the deposition process, although some flattening can occur. 135 When preparing conformal coatings of 3-Dimensiaonl (3D), non-planar substrates with spraying, vacuum can be used to speed up waiting times between spraying and washing. 136 Spray assembly also allows larger non-planar substrates such as plastic shapes to be coated, and can even be used for the assembly of metallic films without any need for electrodeposition.…”

Section: Spray Assemblymentioning

confidence: 99%

“…In general, films are fabricated via spraying polymer solutions onto a substrate and spraying water on the substrate to remove excess unbound polymer (Figure ). , The morphology, chemical composition, and membrane properties can be tailored, based on the polymer concentration, spray duration, flow rate, resting duration, whether the solution is sprayed vertically or horizontally, and whether or not the substrate is washed and for how long. ,,− Although some of these approaches may seem harsh, thermodynamically unstable but kinetically trapped systems, such as lipid vesicles, can remain intact through the deposition process, although some flattening can occur . When preparing conformal coatings of 3-dimensional (3D), nonplanar substrates with spraying, vacuum can be used to speed up waiting times between spraying and washing .…”

Section: Conventional Lbl Assemblymentioning

confidence: 99%

Innovation in Layer-by-Layer Assembly

et al. 2016

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Methods for depositing thin films are important in generating functional materials for diverse applications in a wide variety of fields. Over the last half-century, the layer-by-layer assembly of nanoscale films has received intense and growing interest. This has been fueled by innovation in the available materials and assembly technologies, as well as the film-characterization techniques. In this Review, we explore, discuss, and detail innovation in layer-by-layer assembly in terms of past and present developments, and we highlight how these might guide future advances. A particular focus is on conventional and early developments that have only recently regained interest in the layer-by-layer assembly field. We then review unconventional assemblies and approaches that have been gaining popularity, which include inorganic/organic hybrid materials, cells and tissues, and the use of stereocomplexation, patterning, and dip-pen lithography, to name a few. A relatively recent development is the use of layer-by-layer assembly materials and techniques to assemble films in a single continuous step. We name this "quasi"-layer-by-layer assembly and discuss the impacts and innovations surrounding this approach. Finally, the application of characterization methods to monitor and evaluate layer-by-layer assembly is discussed, as innovation in this area is often overlooked but is essential for development of the field. While we intend for this Review to be easily accessible and act as a guide to researchers new to layer-by-layer assembly, we also believe it will provide insight to current researchers in the field and help guide future developments and innovation.

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“…Various systems have been developed for cotton fabric, such as phosphonated oligoallylamines, chitosan (CH)‐poly(sodium phosphate) (PSP), CH‐ammonium polyphosphate (APP), and silica‐APP . More recent work has focused on improving the industrial feasibility of the LbL process, for example, by spraying the coating instead of dipping, or by using a continuous dipping procedure akin to the padding process used in the textile industry . Additionally, an ultrasonication rinsing step between each deposition step was shown to improve the hand of cotton treated with a CH–PSP system and it also reduced the weight gain necessary to pass a vertical flame test …”

Section: Introductionmentioning

confidence: 99%

Microintumescent mechanism of flame‐retardant water‐based chitosan–ammonium polyphosphate multilayer nanocoating on cotton fabric

Jimenez

Guin

Bellayer

et al. 2016

J of Applied Polymer Sci

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Layer-by-layer (LbL) assembly of nanocoatings on fabric substrates has been very successful in terms of reduction of flammability. In particular, an LbL system comprised ammonium polyphosphate as the polyanion and chitosan as the polycation, applied to cotton fabric, dramatically reduced cotton flammability. At this point, the fire-retardant (FR) mechanism of action of this system has never been fully elucidated. Sonicated and nonsonicated coated cotton fabrics were evaluated using a vertical flame test and mass loss calorimeter. Coating morphology was investigated before and after burning. Thermal analyses and chemical analyses in the condensed phase (and in the gas phase) were conducted to reveal the FR mechanism of action. At the cotton surface, a combination of both condensed (formation of aromatic char) and gas phase (release of water and highly flammable gases) mechanisms impart the FR behavior, promoting a kind of "microintumescence" phenomenon.

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On the distinct molecular architectures of dipping- and spray-LbL films containing lipid vesicles

Cited by 12 publications

References 59 publications

Layer‐by‐Layer Thin Film of Iron Phthalocyanine as a Simple and Fast Sensor for Polyphenol Determination in Tea Samples

Layer‐by‐Layer Thin Film of Iron Phthalocyanine as a Simple and Fast Sensor for Polyphenol Determination in Tea Samples

Innovation in Layer-by-Layer Assembly

Microintumescent mechanism of flame‐retardant water‐based chitosan–ammonium polyphosphate multilayer nanocoating on cotton fabric

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