In recent years, polymers have been popular in industrial applications due to their lightweight, corrosion‐resistant, improved surface polish, ease of manufacturing, cost‐effectiveness, and so forth. Similarly, micro/nano‐indentation has gained popularity as a technique for assessing the surface mechanical characteristics of polymers. The present study conducted comprehensive experiments using cyclic micro‐indentation on engineering polymers, specifically poly‐ether‐ether‐ketone (PEEK), poly(methyl methacrylate) (PMMA), and poly(tetra‐fluoroethylene) (PTFE). An appropriate and optimal indentation method has been proposed after analyzing the behavior and significance of all the input parameters in evaluating the properties. Both constant load multi‐cycle (CLMC) and progressive load multi‐cycle (PLMC) were considered for this investigation. A comparative evaluation has been conducted to assess two multi‐cycle tests on these materials. From the analysis of the input parameters, including maximum loads, loading and unloading rates, and the number of cycles, the unloading rate and indentation cycle are crucial factors in determining hardness (H) and elastic modulus (E). Increasing the loading rates leads to an increase in H and a reduction in E for all three materials. This effect arises from the thermal effect, which is characterized by the creep modulus and a closed hysteresis loop. Employing the holding duration and multiple cycle data in constant load multi‐cycle can significantly influence the creep behavior and use of the hysteresis loop for fatigue behavior. Similarly, a progressive load multi‐cycle indentation with a force greater than 0.5 N and a minimum of five cycles is the most accurate approach for evaluating surface mechanical parameters.
近年来,聚合物因其重量轻、耐腐蚀、表面光洁度高、易于制造、成本效益高等优点而在工业应用中大受欢迎。同样,微/纳米压痕技术作为一种评估聚合物表面机械特性的技术也越来越受欢迎。本研究对工程聚合物,特别是聚醚醚酮(PEEK)、聚甲基丙烯酸甲酯(PMMA)和聚四氟乙烯(PTFE)进行了循环微压痕综合实验。在分析了所有输入参数在性能评估中的行为和意义后,提出了一种适当的最佳压痕方法。本次研究同时考虑了恒定载荷多循环(CLMC)和渐进载荷多循环(PLMC)两种方法。对这些材料的两种多循环测试进行了比较评估。从对输入参数(包括最大载荷、加载和卸载速率以及循环次数)的分析来看,卸载速率和压痕循环是决定硬度(H)和弹性模量(E)的关键因素。对于所有三种材料来说,加载速率的增加都会导致 H 的增加和 E 的减少。这种效应源于热效应,其特点是蠕变模量和闭合滞后环。在恒定载荷多循环中使用保持时间和多循环数据可以显著影响蠕变行为和疲劳行为滞后环的使用。同样,力大于 0.5 N 且至少循环五次的渐进加载多循环压痕是评估表面机械参数的最准确方法。
{"title":"Advancement of constant and progressive load multi‐cycle indentation method on surface properties characterization of polymers","authors":"Soumya Ranjan Guru, Mihir Sarangi","doi":"10.1002/pat.6573","DOIUrl":"https://doi.org/10.1002/pat.6573","url":null,"abstract":"In recent years, polymers have been popular in industrial applications due to their lightweight, corrosion‐resistant, improved surface polish, ease of manufacturing, cost‐effectiveness, and so forth. Similarly, micro/nano‐indentation has gained popularity as a technique for assessing the surface mechanical characteristics of polymers. The present study conducted comprehensive experiments using cyclic micro‐indentation on engineering polymers, specifically poly‐ether‐ether‐ketone (PEEK), poly(methyl methacrylate) (PMMA), and poly(tetra‐fluoroethylene) (PTFE). An appropriate and optimal indentation method has been proposed after analyzing the behavior and significance of all the input parameters in evaluating the properties. Both constant load multi‐cycle (CLMC) and progressive load multi‐cycle (PLMC) were considered for this investigation. A comparative evaluation has been conducted to assess two multi‐cycle tests on these materials. From the analysis of the input parameters, including maximum loads, loading and unloading rates, and the number of cycles, the unloading rate and indentation cycle are crucial factors in determining hardness (<jats:italic>H</jats:italic>) and elastic modulus (<jats:italic>E</jats:italic>). Increasing the loading rates leads to an increase in <jats:italic>H</jats:italic> and a reduction in <jats:italic>E</jats:italic> for all three materials. This effect arises from the thermal effect, which is characterized by the creep modulus and a closed hysteresis loop. Employing the holding duration and multiple cycle data in constant load multi‐cycle can significantly influence the creep behavior and use of the hysteresis loop for fatigue behavior. Similarly, a progressive load multi‐cycle indentation with a force greater than 0.5 N and a minimum of five cycles is the most accurate approach for evaluating surface mechanical parameters.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
γ‐Polyglutamic acid (γ‐PGA) microgel, produced by Bacillus spp., represents a promising biomaterial with diverse industrial applications due to its biodegradability, biocompatibility, and nontoxic nature. This review explores the current methodologies in the industrial production of γ‐PGA microgel, emphasizing the optimization of fermentation conditions, genetic engineering of Bacillus strains, and advances in downstream processing techniques. Key applications in pharmaceuticals, agriculture, and environmental management are discussed, highlighting its role in drug delivery systems, as a biocontrol agent, and in wastewater treatment. Future perspectives include enhancing production efficiency through synthetic biology, expanding its application scope, and addressing economic and regulatory challenges to facilitate broader adoption. The integration of innovative technologies and multidisciplinary approaches is crucial for the sustainable development and commercial success of γ‐PGA microgel.
{"title":"Production of gamma‐polyglutamic acid microgel by Bacillus species: Industrial applications and future perspectives","authors":"Priti Pal, Akhilesh Kumar Singh, Prakash Kumar Sarangi, Uttam Kumar Sahoo, Harikesh B. Singh, Sanjukta Subudhi, Thangjam Anand Singh","doi":"10.1002/pat.6565","DOIUrl":"https://doi.org/10.1002/pat.6565","url":null,"abstract":"γ‐Polyglutamic acid (γ‐PGA) microgel, produced by <jats:italic>Bacillus</jats:italic> spp., represents a promising biomaterial with diverse industrial applications due to its biodegradability, biocompatibility, and nontoxic nature. This review explores the current methodologies in the industrial production of γ‐PGA microgel, emphasizing the optimization of fermentation conditions, genetic engineering of <jats:italic>Bacillus</jats:italic> strains, and advances in downstream processing techniques. Key applications in pharmaceuticals, agriculture, and environmental management are discussed, highlighting its role in drug delivery systems, as a biocontrol agent, and in wastewater treatment. Future perspectives include enhancing production efficiency through synthetic biology, expanding its application scope, and addressing economic and regulatory challenges to facilitate broader adoption. The integration of innovative technologies and multidisciplinary approaches is crucial for the sustainable development and commercial success of γ‐PGA microgel.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The relentless drive towards miniaturization and seamless integration of electronic components in wireless communications and wearable devices has significantly increased the demand for flexible, cost‐effective composites with high dielectric constants and low losses. This study presents a wideband, low‐profile, and flexible antenna with excellent on body radiation performance for wearable applications. The antenna is designed using a low‐loss composite film based on PMMA‐PVDF‐HFP‐PZT and silver‐based ink. The proposed flexible antenna exhibits a wide bandwidth of 132.16% with a voltage standing wave ratio (VSWR) of less than two. It achieves a peak gain of 2.76 dBi at 2.92 GHz and maintains a maximum radiation efficiency of 80% across the 1.26–6.17 GHz frequency range. These characteristics demonstrate that the antenna is an effective solution for achieving high data rates and reliable communication links. The antenna's suitability for wearable applications is assessed by testing it on a simulated human body and analyzing its behavior under physical deformation. The results under bending showed only a minimal frequency detuning, which is negligible given the antenna's wide operational bandwidth. The specific absorption rate (SAR) analysis shows values of approximately 1.88 W/kg at 3.5 GHz with an input power of 0.5 W, and 0.279 W/kg at 5.8 GHz with an input power of 0.45 W, which complies with established safety limits for exposure. Overall, these results suggest that the proposed antenna is a viable solution for integration into wearable medical devices, such as a doctor's chest badge, enabling noncontact interactions and reducing the risk of bacterial contamination.
{"title":"A wideband flexible antenna utilizing PMMA/PVDF‐HFP/PZT polymer composite film and silver‐based conductive ink for wearable applications","authors":"Saïd Douhi, Abdelkrim Boumegnane, Nabil Chakhchaoui, Adil Eddiai, Omar Cherkaoui, M'hammed Mazroui","doi":"10.1002/pat.6575","DOIUrl":"https://doi.org/10.1002/pat.6575","url":null,"abstract":"The relentless drive towards miniaturization and seamless integration of electronic components in wireless communications and wearable devices has significantly increased the demand for flexible, cost‐effective composites with high dielectric constants and low losses. This study presents a wideband, low‐profile, and flexible antenna with excellent on body radiation performance for wearable applications. The antenna is designed using a low‐loss composite film based on PMMA‐PVDF‐HFP‐PZT and silver‐based ink. The proposed flexible antenna exhibits a wide bandwidth of 132.16% with a voltage standing wave ratio (VSWR) of less than two. It achieves a peak gain of 2.76 dBi at 2.92 GHz and maintains a maximum radiation efficiency of 80% across the 1.26–6.17 GHz frequency range. These characteristics demonstrate that the antenna is an effective solution for achieving high data rates and reliable communication links. The antenna's suitability for wearable applications is assessed by testing it on a simulated human body and analyzing its behavior under physical deformation. The results under bending showed only a minimal frequency detuning, which is negligible given the antenna's wide operational bandwidth. The specific absorption rate (SAR) analysis shows values of approximately 1.88 W/kg at 3.5 GHz with an input power of 0.5 W, and 0.279 W/kg at 5.8 GHz with an input power of 0.45 W, which complies with established safety limits for exposure. Overall, these results suggest that the proposed antenna is a viable solution for integration into wearable medical devices, such as a doctor's chest badge, enabling noncontact interactions and reducing the risk of bacterial contamination.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohammadreza Mahdavijalal, Homayon Ahmad Panahi, Elham Moniri, Niloufar Torabi Fard
Levels of anticancer agents in cancer patients' body fluids are typically measured to adjust drug dosages or improve treatment results. The goal of this research is to present a new method for extracting bicalutamide (BCT) from biological samples using a responsive polymeric nanoadsorbent that reacts to temperature and near‐infrared radiation (NIR). To achieve this, the surface layers of tungsten disulfide nanosheets are modified using poly (N‐vinylcaprolactam) and three generations of polymeric dendrimers. The adsorbent product is then characterized using thermogravimetric analysis, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, and X‐ray diffraction techniques. The drug loading operation on the proposed adsorbent is studied through central composite design and response surface strategy, with optimization for temperature (25–45°C), pH (5–9), and contact time (2–18 min). Nonlinear kinetic and adsorption isotherm analysis results show the best fit with Langmuir and pseudo‐second‐order models. The drug release process from the BCT‐loaded adsorbent is investigated via an HPLC‐UV system under both NIR‐irradiated and non‐irradiated conditions. The suggested method demonstrates remarkable recovery rates for BCT spikes from urine (95.23%) and plasma (93.33%), respectively. Overall, the recommended strategy can be regarded as a potent analytical tool for evaluating BCT in complex biosamples.
{"title":"Synthesis, characterization, and optimization of dual‐responsive PAMAM nanodendrimers for improved dispersive solid‐phase extraction of cancer agents from complex biological samples","authors":"Mohammadreza Mahdavijalal, Homayon Ahmad Panahi, Elham Moniri, Niloufar Torabi Fard","doi":"10.1002/pat.6570","DOIUrl":"https://doi.org/10.1002/pat.6570","url":null,"abstract":"Levels of anticancer agents in cancer patients' body fluids are typically measured to adjust drug dosages or improve treatment results. The goal of this research is to present a new method for extracting bicalutamide (BCT) from biological samples using a responsive polymeric nanoadsorbent that reacts to temperature and near‐infrared radiation (NIR). To achieve this, the surface layers of tungsten disulfide nanosheets are modified using poly (N‐vinylcaprolactam) and three generations of polymeric dendrimers. The adsorbent product is then characterized using thermogravimetric analysis, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, and X‐ray diffraction techniques. The drug loading operation on the proposed adsorbent is studied through central composite design and response surface strategy, with optimization for temperature (25–45°C), pH (5–9), and contact time (2–18 min). Nonlinear kinetic and adsorption isotherm analysis results show the best fit with Langmuir and pseudo‐second‐order models. The drug release process from the BCT‐loaded adsorbent is investigated via an HPLC‐UV system under both NIR‐irradiated and non‐irradiated conditions. The suggested method demonstrates remarkable recovery rates for BCT spikes from urine (95.23%) and plasma (93.33%), respectively. Overall, the recommended strategy can be regarded as a potent analytical tool for evaluating BCT in complex biosamples.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shahrzad Shakouri, Sajad Arabshahi, Hamid Madanchi, Mohammad Amin Mohammadifar, Anna Abdolshahi
Bigels are innovative and appealing heterogeneous matrices composed of two structured‐gel (hydrogel and oleogel) phases, which suitable for the entrapment of both hydrophilic and lipophilic active agents. As structuring the bigel phases using convenient materials can enhance the main characteristics, this study aimed to develop bigel system based on a hybrid hydrogel consisting of gelatin and carboxymethylcellulose (CMC). The impact of incorporating various concentrations of CMC (0, 0.5, 1, 2, and 3% w/w) into gelatin‐based hydrogel at a constant organogel/hydrogel ratio of 60:40 was investigated on bigel properties. The integration of gelatin and CMC significantly affected the solvent holding capacity (SHC), microstructure, rheology, thermal, and textural properties. The results showed that bigel samples containing gelatin‐CMC had lower SHC compared to gelatin‐based samples. The integration of CMC to bigel formulation resulted in a significant decrease in hardness, cohesiveness, and adhesiveness also smooth texture. Differential scanning calorimeter (DSC) analysis of the bigels showed a descending trend in melting point from 99.07 to 98.60°C for bigel samples as the CMC concentration increased from 0% to 2%. This was followed by an increase in melting temperature (100.95°C) in the bigel containing 3% CMC. Particle size distribution data indicated that the droplet sizes of the bigels increased with the incorporation of CMC into the hydrogel phase, without displaying a distinct concentration‐dependent trend. The rheological characteristics of strain sweep, frequency sweep, and loss factor affected by gelatin/CMC concentration. Overall obtained results highlight that CMC incorporation to gelatin plays a crucial role in bigel offering different textural, rheological and thermal properties. So that carefully selection and optimization of gelatin and CMC concentrations in hydrogel phase are essential for tailoring the mechanical strength and stability of bigels for various applications such as drug delivery, cosmetic, and food industries. Regarding the desired properties of CMC, it could be recommend to use by combination with gelatin to create a structure–function aimed bigels.
{"title":"Effect of carboxymethyl cellulose incorporation to gelatin‐sunflower oil bigel on the physicochemical and structural properties","authors":"Shahrzad Shakouri, Sajad Arabshahi, Hamid Madanchi, Mohammad Amin Mohammadifar, Anna Abdolshahi","doi":"10.1002/pat.6567","DOIUrl":"https://doi.org/10.1002/pat.6567","url":null,"abstract":"Bigels are innovative and appealing heterogeneous matrices composed of two structured‐gel (hydrogel and oleogel) phases, which suitable for the entrapment of both hydrophilic and lipophilic active agents. As structuring the bigel phases using convenient materials can enhance the main characteristics, this study aimed to develop bigel system based on a hybrid hydrogel consisting of gelatin and carboxymethylcellulose (CMC). The impact of incorporating various concentrations of CMC (0, 0.5, 1, 2, and 3% w/w) into gelatin‐based hydrogel at a constant organogel/hydrogel ratio of 60:40 was investigated on bigel properties. The integration of gelatin and CMC significantly affected the solvent holding capacity (SHC), microstructure, rheology, thermal, and textural properties. The results showed that bigel samples containing gelatin‐CMC had lower SHC compared to gelatin‐based samples. The integration of CMC to bigel formulation resulted in a significant decrease in hardness, cohesiveness, and adhesiveness also smooth texture. Differential scanning calorimeter (DSC) analysis of the bigels showed a descending trend in melting point from 99.07 to 98.60°C for bigel samples as the CMC concentration increased from 0% to 2%. This was followed by an increase in melting temperature (100.95°C) in the bigel containing 3% CMC. Particle size distribution data indicated that the droplet sizes of the bigels increased with the incorporation of CMC into the hydrogel phase, without displaying a distinct concentration‐dependent trend. The rheological characteristics of strain sweep, frequency sweep, and loss factor affected by gelatin/CMC concentration. Overall obtained results highlight that CMC incorporation to gelatin plays a crucial role in bigel offering different textural, rheological and thermal properties. So that carefully selection and optimization of gelatin and CMC concentrations in hydrogel phase are essential for tailoring the mechanical strength and stability of bigels for various applications such as drug delivery, cosmetic, and food industries. Regarding the desired properties of CMC, it could be recommend to use by combination with gelatin to create a structure–function aimed bigels.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Advanced flexible display materials have drastically sparked considerable interest for heat‐resistant, low dielectric, and transparent polyimide (PI) materials. In light of this, our study aims to develop high‐performance semi‐aromatic PI films, followed by investigate the correlations between bridged‐alkyl/heteroaromatic ring structures and their thermal, dielectric, optical, and mechanical properties. Such PI films, namely AP‐PIs, were synthesized with a one‐step high‐temperature method between 4‐[4‐(4‐aminophenoxy) phenyl]‐2‐(4‐aminophenyl)‐1(2H)‐phthalazinone (DHPZDA) and various commercial alicyclic dianhydrides. The incorporation of rigid phthalazinone structures significantly enhanced thermal resistance and mechanical flexibility, while simultaneously reducing their dielectric constant (Dk), attributed to the large polymer internal free volume. Impressively, the prepared films exhibit exceptional glass transition temperature (Tg) as high as 419°C (DMTA tanδ peak), low Dk as low as 2.71, and elongation at break (ε %) up to 50.4%. Furthermore, AP‐PI films demonstrate reasonable solubility and optical transparency within the UV–visible region. The maximum optical transmittance at 550 nm (T550 nm) could reach 83.01%. These desirable properties position these materials as promising candidates for flexible substrate applications.
{"title":"Heat‐resistant and transparent polyimides derived from alicyclic dianhydrides and phthalazinone‐based diamine","authors":"Bingbing Wang, Lishuai Zong, Jinyan Wang, Yabin Zhang, Wenhua Hou, Xigao Jian","doi":"10.1002/pat.6562","DOIUrl":"https://doi.org/10.1002/pat.6562","url":null,"abstract":"Advanced flexible display materials have drastically sparked considerable interest for heat‐resistant, low dielectric, and transparent polyimide (PI) materials. In light of this, our study aims to develop high‐performance semi‐aromatic PI films, followed by investigate the correlations between bridged‐alkyl/heteroaromatic ring structures and their thermal, dielectric, optical, and mechanical properties. Such PI films, namely AP‐PIs, were synthesized with a one‐step high‐temperature method between 4‐[4‐(4‐aminophenoxy) phenyl]‐2‐(4‐aminophenyl)‐1(2H)‐phthalazinone (DHPZDA) and various commercial alicyclic dianhydrides. The incorporation of rigid phthalazinone structures significantly enhanced thermal resistance and mechanical flexibility, while simultaneously reducing their dielectric constant (<jats:italic>D</jats:italic><jats:sub>k</jats:sub>), attributed to the large polymer internal free volume. Impressively, the prepared films exhibit exceptional glass transition temperature (<jats:italic>T</jats:italic><jats:sub>g</jats:sub>) as high as 419°C (DMTA tanδ peak), low <jats:italic>D</jats:italic><jats:sub>k</jats:sub> as low as 2.71, and elongation at break (<jats:italic>ε</jats:italic> %) up to 50.4%. Furthermore, AP‐PI films demonstrate reasonable solubility and optical transparency within the UV–visible region. The maximum optical transmittance at 550 nm (T<jats:sub>550 nm</jats:sub>) could reach 83.01%. These desirable properties position these materials as promising candidates for flexible substrate applications.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Optically clear pressure‐sensitive adhesive (OCA) possesses exceptional optical properties and exhibits pressure‐sensitive adhesion, making it widely utilized in the adhesive layers of various electronic display devices. However, the increasing popularity of foldable mobile phones in recent years has imposed new requirements on the overall performance of OCA. Conventional pressure‐sensitive adhesives can enhance recoverability through cross‐linking but often demonstrate inadequate adhesive strength. In this study, three long‐chain crosslinking agents (CL) were synthesized using hydroxyethyl acrylate (HEA), dicyclohexylmethane diisocyanate (HMDI), polypropylene glycol (PPG), polyether amine (PEA), and hydroxyl‐terminated polybutadiene (R45V). The long‐chain CL agent contains numerous flexible segments that improve the recovery capability of the OCA while maintaining a certain level of adhesion. The optical clear pressure‐sensitive adhesive, crosslinked by three flexible crosslinkers, exhibits a low glass transition temperature (−60 to −40°C) and a low storage modulus (<0.1 MPa), along with an appropriate 180° stripping force (6–8 N/25 mm). Optically transparent pressure‐sensitive adhesives demonstrate excellent recovery properties (>85%), high light transmittance (>92%), and exceptional flexibility. Moreover, compared to market products, the optically transparent pressure‐sensitive adhesive shows superior folding resistance (>100,000 times). This indicates its suitability for applications in flexible optical displays such as foldable mobile phones and wearable electronics.
{"title":"Optically clear pressure‐sensitive adhesive with flexible crosslinking agent for high recovery efficiency, low energy storage modulus, and excellent folding resistance","authors":"Jinbiao Min, Jinqing Qu","doi":"10.1002/pat.6574","DOIUrl":"https://doi.org/10.1002/pat.6574","url":null,"abstract":"Optically clear pressure‐sensitive adhesive (OCA) possesses exceptional optical properties and exhibits pressure‐sensitive adhesion, making it widely utilized in the adhesive layers of various electronic display devices. However, the increasing popularity of foldable mobile phones in recent years has imposed new requirements on the overall performance of OCA. Conventional pressure‐sensitive adhesives can enhance recoverability through cross‐linking but often demonstrate inadequate adhesive strength. In this study, three long‐chain crosslinking agents (CL) were synthesized using hydroxyethyl acrylate (HEA), dicyclohexylmethane diisocyanate (HMDI), polypropylene glycol (PPG), polyether amine (PEA), and hydroxyl‐terminated polybutadiene (R45V). The long‐chain CL agent contains numerous flexible segments that improve the recovery capability of the OCA while maintaining a certain level of adhesion. The optical clear pressure‐sensitive adhesive, crosslinked by three flexible crosslinkers, exhibits a low glass transition temperature (−60 to −40°C) and a low storage modulus (<0.1 MPa), along with an appropriate 180° stripping force (6–8 N/25 mm). Optically transparent pressure‐sensitive adhesives demonstrate excellent recovery properties (>85%), high light transmittance (>92%), and exceptional flexibility. Moreover, compared to market products, the optically transparent pressure‐sensitive adhesive shows superior folding resistance (>100,000 times). This indicates its suitability for applications in flexible optical displays such as foldable mobile phones and wearable electronics.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maryam Aliakbari, Omid Moini Jazani, Majid Moghadam, José Miguel Martín‐Martínez
Epoxy adhesives become very brittle after curing due to their high‐crosslinking degree. For increasing the toughness of epoxy adhesives, the addition of different toughening agents has been proposed. In this study the diglycidyl ether of bisphenol A (DGEBA)/dicyandiamide epoxy network has been modified by adding an emulsion latex containing core–shell rubber particles (CSPs) prepared by means of seeded emulsion polymerization. The CSPs consist of poly (butyl acrylate) (PBA) as core and methyl methacrylate (MMA) copolymerized with glycidyl methacrylate (GMA) as shell. The effects of adding various amounts of the emulsion latex on the mechanical properties, thermal stability, adhesion, and microstructure of the cured epoxy resin were investigated. The CSPs were analyzed by transmission electron microscopy (TEM), Fourier‐transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). The mechanical properties, thermal stability, adhesion to aluminum plates, and microstructure of the cured epoxy resin were investigated by stress–strain, thermal gravimetric analysis (TGA), single lap shear test, and field emission scanning electron microscopy (FESEM), respectively. The addition of 7 wt.% emulsion latex to epoxy enhanced the tensile strength and the toughness of the dumbbell‐shaped samples by 421% and 4388% with respect to neat epoxy, respectively. Furthermore, the single lap shear strength increased in 33% and an increase of 71°C in the initial decomposition temperature of the epoxy was obtained by adding 7 wt.% CSP, without affecting the maximum decomposition temperature. The FESEM micrographs of the fractured surfaces indicated that the major toughening mechanisms were CSP de‐bonding, plastic void growth, and shear bond yielding.
{"title":"Manipulating a novel epoxy‐based composite with core–shell rubber particles for designing a structural adhesive in aluminum–aluminum bonded joints","authors":"Maryam Aliakbari, Omid Moini Jazani, Majid Moghadam, José Miguel Martín‐Martínez","doi":"10.1002/pat.6564","DOIUrl":"https://doi.org/10.1002/pat.6564","url":null,"abstract":"Epoxy adhesives become very brittle after curing due to their high‐crosslinking degree. For increasing the toughness of epoxy adhesives, the addition of different toughening agents has been proposed. In this study the diglycidyl ether of bisphenol A (DGEBA)/dicyandiamide epoxy network has been modified by adding an emulsion latex containing core–shell rubber particles (CSPs) prepared by means of seeded emulsion polymerization. The CSPs consist of poly (butyl acrylate) (PBA) as core and methyl methacrylate (MMA) copolymerized with glycidyl methacrylate (GMA) as shell. The effects of adding various amounts of the emulsion latex on the mechanical properties, thermal stability, adhesion, and microstructure of the cured epoxy resin were investigated. The CSPs were analyzed by transmission electron microscopy (TEM), Fourier‐transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). The mechanical properties, thermal stability, adhesion to aluminum plates, and microstructure of the cured epoxy resin were investigated by stress–strain, thermal gravimetric analysis (TGA), single lap shear test, and field emission scanning electron microscopy (FESEM), respectively. The addition of 7 wt.% emulsion latex to epoxy enhanced the tensile strength and the toughness of the dumbbell‐shaped samples by 421% and 4388% with respect to neat epoxy, respectively. Furthermore, the single lap shear strength increased in 33% and an increase of 71°C in the initial decomposition temperature of the epoxy was obtained by adding 7 wt.% CSP, without affecting the maximum decomposition temperature. The FESEM micrographs of the fractured surfaces indicated that the major toughening mechanisms were CSP de‐bonding, plastic void growth, and shear bond yielding.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Graphene quantum dots (GQDs), owing to their unique optical, electrical, and chemical properties, have emerged as promising nanomaterials for various biomedical applications. This review provides a comprehensive overview of the latest advancements in the utilization of GQDs in tissue engineering, wound healing, drug delivery systems, and other biomedical therapies. The inherent properties of GQDs, including high biocompatibility, tunable photoluminescence, and significant surface area, make them ideal candidates for enhancing medical treatments and diagnostics. In tissue engineering, GQDs improve the mechanical and biological performance of scaffolds, promoting cell proliferation and differentiation. For wound healing, GQDs enhance antimicrobial activity and facilitate faster tissue regeneration. Their potential in DDS is highlighted by their ability to deliver therapeutic agents efficiently, ensuring targeted and controlled release. Additionally, GQDs play a crucial role in biomedical therapies, particularly in cancer treatment, by enhancing drug efficacy and reducing side effects. While GQDs offer significant potential in enhancing medical treatments and diagnostics, challenges such as understanding their long‐term biocompatibility, potential cytotoxicity at higher concentrations, and the need for standardized synthesis methods remain critical areas for further research. This review also discusses the future directions and opportunities for GQDs, emphasizing their transformative potential in advancing modern healthcare solutions. The insights presented here contribute to the expanding field of GQD research, highlighting their potential to significantly enhance patient outcomes and drive healthcare innovations.
{"title":"The role of graphene quantum dots in cutting‐edge medical therapies","authors":"Kosar Arab, Aliakbar Jafari, Farangis Shahi","doi":"10.1002/pat.6571","DOIUrl":"https://doi.org/10.1002/pat.6571","url":null,"abstract":"Graphene quantum dots (GQDs), owing to their unique optical, electrical, and chemical properties, have emerged as promising nanomaterials for various biomedical applications. This review provides a comprehensive overview of the latest advancements in the utilization of GQDs in tissue engineering, wound healing, drug delivery systems, and other biomedical therapies. The inherent properties of GQDs, including high biocompatibility, tunable photoluminescence, and significant surface area, make them ideal candidates for enhancing medical treatments and diagnostics. In tissue engineering, GQDs improve the mechanical and biological performance of scaffolds, promoting cell proliferation and differentiation. For wound healing, GQDs enhance antimicrobial activity and facilitate faster tissue regeneration. Their potential in DDS is highlighted by their ability to deliver therapeutic agents efficiently, ensuring targeted and controlled release. Additionally, GQDs play a crucial role in biomedical therapies, particularly in cancer treatment, by enhancing drug efficacy and reducing side effects. While GQDs offer significant potential in enhancing medical treatments and diagnostics, challenges such as understanding their long‐term biocompatibility, potential cytotoxicity at higher concentrations, and the need for standardized synthesis methods remain critical areas for further research. This review also discusses the future directions and opportunities for GQDs, emphasizing their transformative potential in advancing modern healthcare solutions. The insights presented here contribute to the expanding field of GQD research, highlighting their potential to significantly enhance patient outcomes and drive healthcare innovations.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Gomathi, Nair Deepa, Aiswarya Muraleedharan, Shanmugavel Uma Maheswari, R. Thirumalaisamy, T. Selvankumar, Arunachalam Chinnathambi, Sulaiman Ali Alharbi
The current study aimed to investigate the drug delivery potential of chitosan‐conjugated Spondias pinnata phytocompounds for anticancer and antibacterial applications. The phytochemical composition of the aqueous extract of S. pinnata plant leaves revealed seven major compounds, including stearic acid, 2H‐Indol‐2‐one, beta amyrin, oleic acid, octadecanoic acid, 7‐hexadecenoic acid, and phytol. Additionally, five minor compounds were identified through GC–MS analysis. SEM analysis of chitosan‐conjugated S. pinnata phytocompounds revealed amorphous particles. This demonstrates the attainment of optimized larger crystallites, which differ in size and shape extensively. The antioxidant potential of both the chitosan‐conjugated S. pinnata phytocompounds and S. pinnata leaf extracts was evaluated via DPPH and ABTS assays, and the results revealed that the chitosan‐conjugated S. pinnata phytocompounds exhibited significant scavenging activity, with IC50 values of 18.20 and 33.15 μg/mL, respectively. Chitosan‐conjugated S. pinnata phytocompounds also demonstrated antibacterial activity against four clinically significant infections, with zones of inhibition ranging from 16 ± 0.07, 19 ± 0.10, 17 ± 0.09, and 19 ± 0.11 mm against Escherichia coli (MTCC 452), Salmonella typhi (MTCC 733), Klebsiella pneumonia (MTCC 39), and Pseudomonas aeruginosa (MTCC 1688), respectively. Furthermore, the cytotoxicity of the chitosan‐conjugated S. pinnata phytocompounds was assessed against A549 lung cancer cells, and the results revealed a significant reduction in cell viability (33.85) at higher concentrations of 150 μg/mL. The IC50 values of S. pinnata leaf extract (149.2 mg/mL) and chitosan‐conjugated S. pinnata (126.4 mg/mL) toward A549 lung cancer cells were recorded. Overall, the results of the present study highlight the therapeutic applications of chitosan‐conjugated S. pinnata phytocompounds, particularly in the context of their anticancer and antibacterial activities.
{"title":"Novel drug delivery materials: Chitosan polymers conjugated with Spondias pinnata phytocompounds for enhanced anti‐microbial and anti‐cancer properties","authors":"M. Gomathi, Nair Deepa, Aiswarya Muraleedharan, Shanmugavel Uma Maheswari, R. Thirumalaisamy, T. Selvankumar, Arunachalam Chinnathambi, Sulaiman Ali Alharbi","doi":"10.1002/pat.6561","DOIUrl":"https://doi.org/10.1002/pat.6561","url":null,"abstract":"The current study aimed to investigate the drug delivery potential of chitosan‐conjugated <jats:italic>Spondias pinnata</jats:italic> phytocompounds for anticancer and antibacterial applications. The phytochemical composition of the aqueous extract of <jats:italic>S. pinnata</jats:italic> plant leaves revealed seven major compounds, including stearic acid, 2H‐Indol‐2‐one, beta amyrin, oleic acid, octadecanoic acid, 7‐hexadecenoic acid, and phytol. Additionally, five minor compounds were identified through GC–MS analysis. SEM analysis of chitosan‐conjugated <jats:italic>S. pinnata</jats:italic> phytocompounds revealed amorphous particles. This demonstrates the attainment of optimized larger crystallites, which differ in size and shape extensively. The antioxidant potential of both the chitosan‐conjugated <jats:italic>S. pinnata</jats:italic> phytocompounds and <jats:italic>S. pinnata</jats:italic> leaf extracts was evaluated via DPPH and ABTS assays, and the results revealed that the chitosan‐conjugated <jats:italic>S. pinnata</jats:italic> phytocompounds exhibited significant scavenging activity, with IC<jats:sup>50</jats:sup> values of 18.20 and 33.15 μg/mL, respectively. Chitosan‐conjugated <jats:italic>S. pinnata</jats:italic> phytocompounds also demonstrated antibacterial activity against four clinically significant infections, with zones of inhibition ranging from 16 ± 0.07, 19 ± 0.10, 17 ± 0.09, and 19 ± 0.11 mm against <jats:italic>Escherichia coli</jats:italic> (MTCC 452), <jats:italic>Salmonella typhi</jats:italic> (MTCC 733), <jats:italic>Klebsiella pneumonia</jats:italic> (MTCC 39), and <jats:italic>Pseudomonas aeruginosa</jats:italic> (MTCC 1688), respectively. Furthermore, the cytotoxicity of the chitosan‐conjugated <jats:italic>S. pinnata</jats:italic> phytocompounds was assessed against A549 lung cancer cells, and the results revealed a significant reduction in cell viability (33.85) at higher concentrations of 150 μg/mL. The IC<jats:sup>50</jats:sup> values of <jats:italic>S. pinnata</jats:italic> leaf extract (149.2 mg/mL) and chitosan‐conjugated <jats:italic>S. pinnata</jats:italic> (126.4 mg/mL) toward A549 lung cancer cells were recorded. Overall, the results of the present study highlight the therapeutic applications of chitosan‐conjugated <jats:italic>S. pinnata</jats:italic> phytocompounds, particularly in the context of their anticancer and antibacterial activities.","PeriodicalId":20382,"journal":{"name":"Polymers for Advanced Technologies","volume":null,"pages":null},"PeriodicalIF":3.4,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}