Alternating Gyroid Network Structure in an ABC Miktoarm Terpolymer Comprised of Polystyrene and Two Polydienes

The synthesis, molecular and morphological characterization of a 3-miktoarm star terpolymer of polystyrene (PS, M¯¯¯¯n = 61.0 kg/mol), polybutadiene (PB, M¯¯¯¯n = 38.2 kg/mol) and polyisoprene (PI, M¯¯¯¯n = 29.2 kg/mol), corresponding to volume fractions (φ) of 0.46, 0.31 and 0.23 respectively, was studied. The major difference of the present material from previous ABC miktoarm stars (which is a star architecture bearing three different segments, all connected to a single junction point) with the same block components is the high 3,4-microstructure (55%) of the PI chains. The interaction parameter and the degree of polymerization of the two polydienes is sufficiently positive to create a three-phase microdomain structure as evidenced by differential scanning calorimetry and transmission electron microscopy (TEM). These results in combination with small-angle X-ray scattering (SAXS) and birefringence experiments suggest a cubic tricontinuous network structure, based on the I4132 space group never reported previously for such an architecture

Evaluating Ontology-Based PD Monitoring and Alerting in Personal Health Knowledge Graphs and Graph Neural Networks

In the realm of Parkinson’s Disease (PD) research, the integration of wearable sensor data with personal health records (PHR) has emerged as a pivotal avenue for patient alerting and monitoring. This study delves into the complex domain of PD patient care, with a specific emphasis on harnessing the potential of wearable sensors to capture, represent and semantically analyze crucial movement data and knowledge. The primary objective is to enhance the assessment of PD patients by establishing a robust foundation for personalized health insights through the development of Personal Health Knowledge Graphs (PHKGs) and the employment of personal health Graph Neural Networks (PHGNNs) that utilize PHKGs. The objective is to formalize the representation of related integrated data, unified sensor and PHR data in higher levels of abstraction, i.e., in a PHKG, to facilitate interoperability and support rule-based high-level event recognition such as patient’s missing dose or falling. This paper, extending our previous related work, presents the Wear4PDmove ontology in detail and evaluates the ontology within the development of an experimental PHKG. Furthermore, this paper focuses on the integration and evaluation of PHKG within the implementation of a Graph Neural Network (GNN). This work emphasizes the importance of integrating PD-related data for monitoring and alerting patients with appropriate notifications. These notifications offer health experts precise and timely information for the continuous evaluation of personal health-related events, ultimately contributing to enhanced patient care and well-informed medical decision-making. Finally, the paper concludes by proposing a novel approach for integrating personal health KGs and GNNs for PD monitoring and alerting solutions

Nanoparticle Directed Domain Orientation in Thin Films of Asymmetric Block Copolymers

We investigated the thin film morphology of two different asymmetric block copolymers (BCP), polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) and poly(n-pentyl methacrylate)-block-poly(methyl methacrylate) (PPMA-b-PMMA), loaded with pre-synthesized iron oxide nanoparticles (NP). The chemical composition of the BCP constituents determines the strength of the interaction between polymer chains and nanoparticles. In the case of NP/PS-b-P4VP system, the nanoparticles interact preferentially with the P4VP block and hence localize selectively in the P4VP cylindrical microdomains. However, for the NP/PPMA-b-PMMA system, the nanoparticles have no significant preference for the copolymer blocks and segregate at the polymer/substrate interface. Interestingly, this changes the effective substrate surface energy and hence leads to a remarkable change in domain orientation from parallel to perpendicular with respect to the substrate. These results clearly demonstrate the importance of both enthalpic and entropic factors which determine spatial distribution of NP in BCP films and influence domain orientation

Synthesis of a Novel Chitosan/Basil Oil Blend and Development of Novel Low Density Poly Ethylene/Chitosan/Basil Oil Active Packaging Films Following a Melt-Extrusion Process for Enhancing Chicken Breast Fillets Shelf-Life

An innovative process for the adsorption of the hydrophobic Basil-Oil (BO) into the hydrophilic food byproduct chitosan (CS) and the development of an advanced low-density polyethylene/chitosan/basil-oil (LDPE/CS_BO) active packaging film was investigated in this work. The idea of this study was the use of the BO as both a bioactive agent and a compatibilizer. The CS was modified to a CS_BO hydrophobic blend via a green evaporation/adsorption process. This blend was incorporated directly in the LDPE to produce films with advanced properties. All the obtained composite films exhibited improved packaging properties. The film with 10% CS_BO content exhibited the best packaging properties, i.e., 33.0% higher tensile stress, 31.0% higher water barrier, 54.3% higher oxygen barrier, and 12.3% higher antioxidant activity values compared to the corresponding values of the LDPE films. The lipid oxidation values of chicken breast fillets which were packaged under vacuum using this film were measured after seven and after fourteen days of storage. These values were found to be lower by around 41% and 45%, respectively, compared with the corresponding lipid oxidation values of pure LDPE film

Novel organo-functional titanium-oxo-cluster-based hybrid materials with enhanced thermomechanical and thermal properties

Two novel nanomaterials based on hybrid organic-inorganic polymers have been prepared via free radical polymerization of (I) dimethacrylate oligomers and (II) 2-hydroxyethyl methacrylate (HEMA) in the presence of different contents of organically modified titanium-oxo-clusters Ti16O16(OEt)24- (OC2H4Mc)8 (OMc ) methacrylate). Investigations, combining small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM), and energy-filtering transmission electron microscopy (EFTEM) lead to consistent structural and morphological characteristics for both grades of hybrid materials. Structural features, such as the subunit size and fractal dimensions are extracted from SAXS profiles. For the first grade of nanomaterials, i.e., for different content of titanium-oxo-clusters (2.5, 5 and 7.5 wt %) incorporated into a dimethacrylate-based matrix, aggregates with ramified mass fractal structures were found. Semiquantitative studies of TEM and EFTEM images revealed the presence of a uniform size distribution in the case of 2.5 wt % titanium cluster content with a typical size of 30 nm. A larger size distribution has been found for the 5 wt % and 7.5 wt % between 30 and 180 nm. For the second grade of nanomaterials, i.e., the 19.2 wt % of organically modified titanium clusters incorporated into poly(HEMA), compact and highly dense aggregates with a size distribution from a few nm up to 50 nm were found from TEM and EFTEM images. A significant increase of the storage modulus for the first grade of nanomaterials was revealed by dynamic mechanical analysis (DMA). The incorporation of Ti nanoclusters in the matrix lead to a significant alteration of the system's hardness as indicated through nano-indentation measurements. Thermogravimetric analysis also indicated a significant enhancement of the thermal stability compared to the neat matrix, probably because of the antioxidant effect of the titanium-oxo-clusters

Development, Characterization, and Evaluation as Food Active Packaging of Low-Density-Polyethylene-Based Films Incorporated with Rich in Thymol Halloysite Nanohybrid for Fresh “Scaloppini” Type Pork Meat Fillets Preservation

A new era is rising in food packaging and preservation, with a consequent focus on transition to “greener” and environmentally friendly techniques. The environmental problems that are emerging nowadays impose use of natural materials for food packaging applications, replacement of chemical preservatives with natural organic extractions, such as essential oils, and targeting of new achievements, such as further extension of food shelf-life. According to this new philosophy, most of the used materials for food packaging should be recyclable, natural or bio-based, and/or edible. The aim of this work was to investigate use and efficiency of a novel food packaging developed based on commercial LDPE polymer incorporated with natural material halloysite impregnated with natural extract of thyme oil. Moreover, a direct correlation between the stiff TBARS method and the easiest heme iron measurements method was scanned to test food lesions easier and faster. The result of this study was development of the LDPE/10TO@HNT film, which contains the optimum amount of a hybrid nanostructure and is capable to be used as an efficient active food packaging film. Furthermore, a linear correlation seems to connect the TBARS and heme iron measurements

Block copolymer concentration gradient and solvent effects on nanostructuring of thin epoxy coatings modified with epoxidized styrene-butadiene-styrene block copolymers

The gradient on block copolymer concentration through film thickness as well as the effects of casting solvents used on the nanostructuring of a thermosetting epoxy coating modified with an epoxidized poly(styrene-b- butadiene-b-styrene) (SBS) triblock copolymer was studied by means of atomic force microscopy and attenuated total reflectance infrared spectroscopy. Thin coating films based on a commercial epoxy-amine formulation consisting of diglycidyl ether of bisphenol A and a low-temperature fast curing amine were modified with several amounts of epoxidized SBS triblock copolymer. Toluene and a mixture of tetrahydrofuran and N,N-dimethylformamide were used as casting solvents. With epoxidation degrees higher than 45 mol % of polybutadiene block nanostructuring was achieved. Fast curing rate of the epoxy/amine system and the comparatively slow evaporation rate of the casting solvent led to a gradient of morphologies through the film cross section owing to the coalescence of small micelles into larger micellar domains in the case of low block copolymer content. For these reasons, different morphologies were also obtained in the midtransverse section of a film with variable thickness. Finally, pseudolamellar nanostructure at high copolymer contents was achieved as confirmed by parallel and perpendicular cuttings to the air/polymer interface. © 2012 American Chemical Society.Fil: Ramos, José Angel. Universidad del País Vasco; EspañaFil: Espósito, Leandro Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad del País Vasco; EspañaFil: Fernández, Raquel. Universidad del País Vasco; EspañaFil: Zalakain, Iñaki. Universidad del País Vasco; EspañaFil: Goyanes, Silvia Nair. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Física. Laboratorio de Polímeros y Materiales Compuestos; ArgentinaFil: Avgeropoulos, Apostolos. University of Ioannina; GreciaFil: Zafeiropoulos, Nikolaos E.. University of Ioannina; GreciaFil: Kortaberria, Galder. Universidad del País Vasco; EspañaFil: Mondragon, Iñaki. Universidad del País Vasco; Españ