Macromol最新文献_第6页

Active Agents Incorporated in Polymeric Substrates to Enhance Antibacterial and Antioxidant Properties in Food Packaging Applications 在高分子基质中加入活性剂以增强食品包装中的抗菌和抗氧化性能

Macromol Pub Date : 2022-12-23 DOI: 10.3390/macromol3010001

John W. Stanley, Athira John, Klementina Pušnik Črešnar, L. FRAS ZEMLJIČ, D. Lambropoulou, D. Bikiaris

{"title":"Active Agents Incorporated in Polymeric Substrates to Enhance Antibacterial and Antioxidant Properties in Food Packaging Applications","authors":"John W. Stanley, Athira John, Klementina Pušnik Črešnar, L. FRAS ZEMLJIČ, D. Lambropoulou, D. Bikiaris","doi":"10.3390/macromol3010001","DOIUrl":"https://doi.org/10.3390/macromol3010001","url":null,"abstract":"Active packaging has played a significant role in consumers’ health and green environment over the years. Synthetic polymers, such as poly(ethylene terephthalate) (PET), polyethylene (PE), polypropylene (PP), polystyrene, poly(vinyl chloride) (PVC), polycarbonate (PC), poly(lactic acid) (PLA), etc., and naturally derived ones, such as cellulose, starch, chitosan, etc., are extensively used as packaging materials due to their broad range of desired properties (transparence, processability, gas barrier properties, mechanical strength, etc.). In recent years, the food packaging field has been challenged to deliver food products free from microbes that cause health hazards. However, most of the used polymers lack such properties. Owing to this, active agents such as antimicrobial agents and antioxidants have been broadly used as potential additives in food packaging substrates, to increase the shelf life, the quality and the safety of food products. Both synthetic active agents, such as Ag, Cu, ZnO, TiO2, nanoclays, and natural active agents, such as essential oils, catechin, curcumin, tannin, gallic acid, etc., exhibit a broad spectrum of antimicrobial and antioxidant effects, while restricting the growth of harmful microbes. Various bulk processing techniques have been developed over the years to produce appropriate food packaging products and to add active agents on polymer matrices or on their surface. Among these techniques, extrusion molding is the most used method for mass production of food packaging with incorporated active agents into polymer substrates, while injection molding, thermoforming, blow molding, electrospinning, etc., are used to a lower extent. This review intends to study the antimicrobial and antioxidant effects of various active agents incorporated into polymeric substrates and their bulk processing technologies involved in the field of food packaging.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91089520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

A Review of Xyloglucan: Self-Aggregation, Hydrogel Formation, Mucoadhesion and Uses in Medical Devices 木葡聚糖:自聚集、水凝胶形成、黏附及其在医疗器械中的应用综述

Macromol Pub Date : 2022-12-06 DOI: 10.3390/macromol2040037

J. Esquena-Moret

{"title":"A Review of Xyloglucan: Self-Aggregation, Hydrogel Formation, Mucoadhesion and Uses in Medical Devices","authors":"J. Esquena-Moret","doi":"10.3390/macromol2040037","DOIUrl":"https://doi.org/10.3390/macromol2040037","url":null,"abstract":"The present paper reviews the self-aggregation, gel-forming and adsorption properties of xyloglucan (XG), and its main applications as a medical device for wound dressings, mucosal protection and ocular lubrication, as well as its uses as an excipient. XG is a branched polysaccharide composed of a central backbone of D-glucose units linked by β(1→4)-glycosidic bonds, decorated with D-xylose units through α(1→6) glycosidic bonds, and with some D-galactose units anchored to these D-xylose units via β(1→2) bonds. XG forms self-aggregates with a hierarchically ordered morphology in aqueous solutions, leading to the formation of nanofibers. Consequently, XG is a hydrogel-forming polymer able to retain large amounts of water. Inside the human digestive tract, XG is enzymatically degalactosylated, but the backbone with xylose side chains remains stable until excretion. Degalactosylated XG undergoes a fully reversible sol–gel transition, forming hydrogels between upper and lower critical temperatures. XG adsorbs on intestinal mucosa and creates a diffusion barrier that reduces permeability and also prevents bacterial infections by reducing their infiltration. Therefore, orally administered XG is considered a mucosa protectant.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88196960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Novel Method of Carbon Precursor Masking to Generate Controlled Perforations in a Carbon Film 碳前驱体掩膜在碳膜上产生可控穿孔的新方法

Macromol Pub Date : 2022-12-05 DOI: 10.3390/macromol2040036

R. Rouhana, M. Stommel, M. Stanko, M. Muth

引用次数: 1

Fabrication and Characterization of Free-Standing and Flexible Polyaniline Membranes: Role of Graphene Nanoscrolls 独立柔性聚苯胺膜的制备与表征:石墨烯纳米卷的作用

Macromol Pub Date : 2022-11-21 DOI: 10.3390/macromol2040035

Rauf Mahmudzade, D. Depan

{"title":"Fabrication and Characterization of Free-Standing and Flexible Polyaniline Membranes: Role of Graphene Nanoscrolls","authors":"Rauf Mahmudzade, D. Depan","doi":"10.3390/macromol2040035","DOIUrl":"https://doi.org/10.3390/macromol2040035","url":null,"abstract":"Wearable technologies can contribute to the early and accurate detection of chronic diseases which can be achieved by the integration of biosensors into wearable technologies. However, the challenges associated with the performance of current electrode materials—i.e., flexibility, conductivity, and mechanical stability, made from conducting polymers are preventing their widespread usage. Herein, we report a freestanding and flexible electrode synthesized from polyaniline (PANI) and graphene nanoscrolls (GNS). The PANI-GNS nanohybrid membranes were synthesized via chemical oxidative polymerization and characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), nanoindentation (NI), and four-point probe techniques. FTIR results showed an increase in conjugation length of the PANI after the addition of GNS into the mixture which can be indicative of an enhancement of electrical properties. Nanoindentation studies showed an elastic modulus and hardness of 2.6 GPa and 0.17 GPa, respectively, for PANI-GNS-5 nanocomposite, compared to 1.9 GPa and 0.08 GPa, for pure PANI. This was later confirmed by the four-point probe technique as the addition of GNS increased the conductivity of electrodes up to 9 S/cm at a 5% weight ratio. Moreover, SEM results of the PANI-GNS showed an open porous morphology of the polymer matrix in comparison with pure PANI samples which would readily translate into higher amounts of enzyme immobilization on the surface.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86495772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Characterization of a Biocomposite of Electrospun PVDF Membranes with Embedded BaTiO3 Micro- and Nanoparticles 电纺丝PVDF膜包埋BaTiO3微粒子和纳米粒子生物复合材料的表征

Macromol Pub Date : 2022-11-17 DOI: 10.3390/macromol2040034

S. Almeida, J. Silva, J. Borges, M. Lança

{"title":"Characterization of a Biocomposite of Electrospun PVDF Membranes with Embedded BaTiO3 Micro- and Nanoparticles","authors":"S. Almeida, J. Silva, J. Borges, M. Lança","doi":"10.3390/macromol2040034","DOIUrl":"https://doi.org/10.3390/macromol2040034","url":null,"abstract":"Damage to bone tissue is a common health issue that tends to increase in severity with age and other underlying conditions. To take advantage of the piezoelectric effect on bone remodulation, piezoelectric materials can be used to fill patients bone defects. Polyvinylidene fluoride (PVDF) and barium titanate (BaTiO3) are both well-known polymeric and ceramic biomaterials, respectively, as well as piezoelectric at room temperature. To mimic the extracellular matrix, PVDF membranes were produced by electrospinning onto a rotating drum to promote the alignment of fibers and micro- and nano-sized tetragonal BaTiO3 particles were embedded into these membranes to try to enhance the piezoelectric response and, therefore, bioactivity. After defining the best deposition parameters to produce pure PVDF membranes, the same parameters were carried over for the embedded membranes and both were characterized, revealing that the proposed method for obtaining β-phase PVDF (the polymer phase with highest piezoelectric coefficient) through electrospinning is viable, producing fibers with coherent diameters and alignment. The presence of barium titanate conferred bioactivity to the membranes and caused a decrease in fibers’ diameter and in superficial charge density.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"262 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77018007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enzymatic Degradation of Fiber-Reinforced PLA Composite Material 纤维增强PLA复合材料的酶解研究

Macromol Pub Date : 2022-10-27 DOI: 10.3390/macromol2040033

E. Urinov, S. Hanstein, A. Weidenkaff

{"title":"Enzymatic Degradation of Fiber-Reinforced PLA Composite Material","authors":"E. Urinov, S. Hanstein, A. Weidenkaff","doi":"10.3390/macromol2040033","DOIUrl":"https://doi.org/10.3390/macromol2040033","url":null,"abstract":"Application of thermoplastic fiber-reinforced lightweight composite materials provides a wide range of advantages that are of particular importance for the mobility sector. UD tapes composed of unidirectionally (UD) oriented inorganic fibers embedded in a thermoplastic matrix represent light-weight materials with high tensile strength. This publication addresses recycling aspects of novel UD tape made of a combination of basalt fibers and different PLA (polylactic acid) formulations. The kinetics of enzyme-based separation of polymer from the fiber were investigated. Different types of UD tapes with a thickness of 270–290 µm reinforced with basalt fiber weight ratios ranging between 51 and 63% were incubated at 37 °C in buffer solution (pH 7.4) containing proteinase K. The influence of enzyme concentration, tape weight per incubation tube, proteinase K activators, and tape types on the rate of enzymatic decomposition was investigated. Enzyme activity was measured by analyzing lactate concentration with lactate dehydrogenase and by measuring weight loss of the composite material. The rate of lactate release increased in the first 30 min of incubation and remained stable for at least 90 min. Weight loss of 4% within 4 h was achieved for a tape with 56% (w/w) fiber content. For a sample with a surface area of 3 cm2 in a buffer volume of 10 mL, the rate of lactate release as a function of enzyme concentration reached saturation at 300 µg enzyme/mL. With this enzyme concentration, the rate of lactate release increased in a linear manner for tape surface areas between 1 and 5 cm2. Four tapes with different PLA types were treated with the enzyme for 17 h. Weight loss ranged between 7 and 24%. Urea at a concentration of 0.5% (w/v) increased lactate release by a factor of 9. Pretreatment of tapes in alkaline medium before enzymatic degradation increased weight loss to 14% compared to 5% without pretreatment. It is concluded that enzymatic PLA hydrolysis from UD tapes is a promising technology for the release of basalt fibers after alkaline pretreatment or for the final cleaning of basalt fibers.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88069724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanical Response of Reactive Extruded Biocomposites Based on Recycled Poly(lactic Acid) (R-PLA)/Recycled Polycarbonate (R-PC) and Cellulosic Fibers with Different Aspect Ratios 基于再生聚乳酸(R-PLA)/再生聚碳酸酯(R-PC)和不同长径比纤维素纤维的反应性挤出生物复合材料的力学响应

Macromol Pub Date : 2022-10-26 DOI: 10.3390/macromol2040032

V. Gigante, Laura Aliotta, M. Coltelli, A. Lazzeri

引用次数: 0

Copolymerization of Ethylene and Methyl Acrylate by Dibenzocycloheptyl-Substituted Aryliminopyridyl Ni(II) Catalysts 二苯并环庚基取代芳基吡啶镍催化乙烯与丙烯酸甲酯共聚的研究

Macromol Pub Date : 2022-10-23 DOI: 10.3390/macromol2040031

I. D’Auria, Z. Saki, Ming Liu, Wen‐Hua Sun, C. Pellecchia

引用次数: 2

Influencing the Shape Recovery and Thermomechanical Properties of 3DP PLA Using Smart Textile and Boehmite Alumina and Thermochromic Dye Modifiers 智能纺织品、薄铝铝及热致变色染料改性剂对3DP PLA形状恢复及热机械性能的影响

Macromol Pub Date : 2022-09-18 DOI: 10.3390/macromol2030030

Dimakatso Makwakwa, M. Motloung, V. Ojijo, J. Bandyopadhyay, S. Ray

{"title":"Influencing the Shape Recovery and Thermomechanical Properties of 3DP PLA Using Smart Textile and Boehmite Alumina and Thermochromic Dye Modifiers","authors":"Dimakatso Makwakwa, M. Motloung, V. Ojijo, J. Bandyopadhyay, S. Ray","doi":"10.3390/macromol2030030","DOIUrl":"https://doi.org/10.3390/macromol2030030","url":null,"abstract":"The technology of 4DP utilizes shape memory materials (SMMs). Among the SMMs, SMP is the material that has potential and is ideal for this technology. However, due to their restrictions, fillers are incorporated to produce a novel shape memory polymer composite (SMPC). The objective of the present work was to investigate how the modification of PLA via the incorporation of boehmite alumina and thermochromic dye, and the use of 3DP on polyester fabric to make smart material textiles (SMT), influenced the shape-memory properties of printed objects. SMPCs with 3 wt% BA particles were prepared by means of the fused deposition modelling (FDM) process, with heat used as an actuation. It was demonstrated that sample thickness and the method of PLA modification affected the shape recovery of 3D-printed objects. All neat PLA samples recovered their angle fully for all thicknesses, while modified PLA incorporated with BA particles and dye recovered its initial angle fully at 1 mm thickness and showed less recovery for 1.5- and 2 mm-thicknesses. The 1 mm-thick sample was then chosen for printing onto the textile material for all samples. When printed onto the fabric, the neat PLA and SMPCs recovered their initial shapes fully, while samples with the dye added into the PLA and SMPC did not recover their initial shape fully due to the presence of the dye, which hindered the movement of the polymer chains. SEM revealed good layer bonding for the SMPCs compared to the neat PLA, which led to improved mechanical properties. The thermal stability of PLA was improved by the BA particles; furthermore, the dye and BA particles nucleated the crystallization of PLA, resulting in an enhanced storage modulus. Overall, a biodegradable 3D-printed object of 1 mm in thickness with improved thermal and mechanical properties was produced, with and without the use of the textile.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80089061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Impact of Exogenous Nitric Oxide Treatment on Vascularization of a Subcutaneous Device for Cell Transplantation 外源性一氧化氮处理对细胞移植皮下装置血管化的影响

Macromol Pub Date : 2022-09-18 DOI: 10.3390/macromol2030029

A. Smink, Bryan Ceballos, T. Koster, S. Rodriquez, M. Alexander, J. Lakey, P. de Vos

{"title":"Impact of Exogenous Nitric Oxide Treatment on Vascularization of a Subcutaneous Device for Cell Transplantation","authors":"A. Smink, Bryan Ceballos, T. Koster, S. Rodriquez, M. Alexander, J. Lakey, P. de Vos","doi":"10.3390/macromol2030029","DOIUrl":"https://doi.org/10.3390/macromol2030029","url":null,"abstract":"Subcutaneous polymer scaffolds have shown potential for creating an optimal transplantation site in cellular replacement therapy, e.g., when transplanting insulin-producing cells to cure type 1 diabetes. Imperative for these scaffolds is a high degree of vascularization to guarantee long-term functional cellular survival. In this study, the effect of the nitric oxide (NO) donor S-nitroso-N-acetyl-dl-penicillamine (SNAP) on the vascularization degree of a subcutaneous poly(d,l-lactide-co-ε-caprolactone) (PDLLCL) scaffold was investigated. To this end, scaffolds were implanted under the skin of C57BL/6 mice. Each mouse received a control scaffold and a scaffold containing SNAP. At day 7, 14, and 28, the oxygen percentage within the scaffolds was measured and at day 28, the vascularization degree was determined with lectin infusion and gene expression analysis. We measured lower oxygen percentages within the scaffolds containing the NO-donor up to day 14 compared to the control scaffolds, but no differences were found at day 28. Although blood vessels in the scaffolds were well perfused, no differences between the groups were found in the lectin staining and gene expression of vascular markers, such as CD31, CD105, and VEGFa. To conclude, in this biomaterial setting, addition of a NO-donor did not improve the vascularization degree of the subcutaneous scaffold.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82761259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0