Michelle M. Jarvie, Thu N. T. Nguyen, Benjamin Southwell, Derek Wright
The prevalence of coronavirus disease 2019 (Covid-19) in the community has become more difficult to gauge utilizing clinical testing due to a decrease in reported test results stemming from the availability of at-home test kits and a reduction in the number of cases seeking medical treatment. The purpose of this study was to examine the trend of diminishing correlation between reported clinical cases of Covid-19 and wastewater-based surveillance epidemiological data as home testing became available in the Eastern Upper Peninsula of Michigan. Wastewater grab samples were collected weekly from 16 regional locations from June 2021 to December 2022. Samples were analyzed for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) N1 and N2 viral particles using reverse transcriptase digital droplet polymerase chain reaction (RT ddPCR). N1 and N2 gene copies were correlated with clinical cases. The t test was used to determine the correlation deterioration point. Clinical cases postdeterioration were calculated for high-correlated predeterioration locations using linear regression. Correlation between the wastewater-based surveillance of SARS-CoV-2 and reported clinical cases deteriorated after February 1, 2022. This corresponds with the timeframe in which commercially available at-home test kits became available in the United States. The increase in at-home testing for SARS-CoV-2 likely contributed to the decrease in reported clinical positive tests in early 2022, providing an unrealistic picture of the presence of Covid-19 in the community. As measures to reduce exposure such as personal masking, clinical testing, social isolating, and quarantining continue to decline, wastewater surveillance for the presence of SARS-CoV-2 may be the best method for public health professionals to remain aware of virus dynamics in localized regions. Time-series modeling adds another layer of information when clinical data is unobtainable or underreported.
{"title":"Leveraging wastewater surveillance to actively monitor Covid-19 community dynamics in rural areas with reduced reliance on clinical testing","authors":"Michelle M. Jarvie, Thu N. T. Nguyen, Benjamin Southwell, Derek Wright","doi":"10.1002/appl.202400012","DOIUrl":"10.1002/appl.202400012","url":null,"abstract":"<p>The prevalence of coronavirus disease 2019 (Covid-19) in the community has become more difficult to gauge utilizing clinical testing due to a decrease in reported test results stemming from the availability of at-home test kits and a reduction in the number of cases seeking medical treatment. The purpose of this study was to examine the trend of diminishing correlation between reported clinical cases of Covid-19 and wastewater-based surveillance epidemiological data as home testing became available in the Eastern Upper Peninsula of Michigan. Wastewater grab samples were collected weekly from 16 regional locations from June 2021 to December 2022. Samples were analyzed for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) N1 and N2 viral particles using reverse transcriptase digital droplet polymerase chain reaction (RT ddPCR). N1 and N2 gene copies were correlated with clinical cases. The <i>t</i> test was used to determine the correlation deterioration point. Clinical cases postdeterioration were calculated for high-correlated predeterioration locations using linear regression. Correlation between the wastewater-based surveillance of SARS-CoV-2 and reported clinical cases deteriorated after February 1, 2022. This corresponds with the timeframe in which commercially available at-home test kits became available in the United States. The increase in at-home testing for SARS-CoV-2 likely contributed to the decrease in reported clinical positive tests in early 2022, providing an unrealistic picture of the presence of Covid-19 in the community. As measures to reduce exposure such as personal masking, clinical testing, social isolating, and quarantining continue to decline, wastewater surveillance for the presence of SARS-CoV-2 may be the best method for public health professionals to remain aware of virus dynamics in localized regions. Time-series modeling adds another layer of information when clinical data is unobtainable or underreported.</p>","PeriodicalId":100109,"journal":{"name":"Applied Research","volume":"3 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/appl.202400012","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140263421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Academic translational research efforts to industry are often an underlying sought-after goal among various researchers. Through the interchanges of research endeavors between academia-industry, great innovations can/has been achieved that cater to the real-world application by bridging “industrially relevant” problem solving with pursuing fundamental studies. It is pertinent that most of the studies from university-level research works may not translate into demonstrable market products due to various reasons. Funding support, individual researcher goals, socioeconomic factors, and most importantly the technical know-how of generating revenue strategies for startups, are a few of the factors that have slowed the pace of collaborative efforts. However, we believe that the most crucial component is the identification of the critical parameters that solve long-standing problems that hinder the scale-up of the lab scale research into marketable products considering the techno-economic analysis. To illustrate this, we take the three most relevant examples of devices for fuel generation, devices to utilize solar radiation, and devices for detection and other related applications. In this perspective, we provide an in-depth case study of each of these critical parameters to comment on the direction of research avenues that can serve as step-stones for the commercialization of university-level lab research studies.
{"title":"Narrowing lab-to-market gaps: Device innovations in fuel generation, solar-cell, and photodetection","authors":"Sukanta Nandi, Raaghesh Vijayan, Manjeet Chhetri","doi":"10.1002/appl.202300109","DOIUrl":"10.1002/appl.202300109","url":null,"abstract":"<p>Academic translational research efforts to industry are often an underlying sought-after goal among various researchers. Through the interchanges of research endeavors between academia-industry, great innovations can/has been achieved that cater to the real-world application by bridging “industrially relevant” problem solving with pursuing fundamental studies. It is pertinent that most of the studies from university-level research works may not translate into demonstrable market products due to various reasons. Funding support, individual researcher goals, socioeconomic factors, and most importantly the technical know-how of generating revenue strategies for startups, are a few of the factors that have slowed the pace of collaborative efforts. However, we believe that the most crucial component is the identification of the critical parameters that solve long-standing problems that hinder the scale-up of the lab scale research into marketable products considering the techno-economic analysis. To illustrate this, we take the three most relevant examples of devices for fuel generation, devices to utilize solar radiation, and devices for detection and other related applications. In this perspective, we provide an in-depth case study of each of these critical parameters to comment on the direction of research avenues that can serve as step-stones for the commercialization of university-level lab research studies.</p>","PeriodicalId":100109,"journal":{"name":"Applied Research","volume":"3 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/appl.202300109","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140263527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eszter E. Najbauer, Lucza Sinkó, Szilvia Biró, Zsolt Durkó, Peter Basa
Silicon epitaxy is an essential building block in the manufacturing of complementary metal-oxide semiconductor (CMOS) devices. Accurate determination of epitaxial layer thickness is indispensable for a uniform and reproducible process. In this paper, we compare thickness values of the transition zone (TZ) in silicon epitaxial wafers obtained by two of Semilab's production-compatible electrical and optical characterization techniques: Fourier-transform infrared (FTIR) reflectometry and spreading resistance profiling (SRP). We demonstrate a high correlation between TZ thicknesses obtained from the optical modeling of FTIR reflectance spectra and SRP profiles. The dependence of TZ thickness change on the high-temperature annealing steps is also examined. FTIR reflectometry thus offers a quick, contactless alternative for obtaining structural parameters of an epitaxial layer, and these values can be well matched to those given by SRP.
{"title":"Epitaxial silicon transition zone measurements by spreading resistance profiling and Fourier transform infrared reflectometry","authors":"Eszter E. Najbauer, Lucza Sinkó, Szilvia Biró, Zsolt Durkó, Peter Basa","doi":"10.1002/appl.202300146","DOIUrl":"10.1002/appl.202300146","url":null,"abstract":"<p>Silicon epitaxy is an essential building block in the manufacturing of complementary metal-oxide semiconductor (CMOS) devices. Accurate determination of epitaxial layer thickness is indispensable for a uniform and reproducible process. In this paper, we compare thickness values of the transition zone (TZ) in silicon epitaxial wafers obtained by two of Semilab's production-compatible electrical and optical characterization techniques: Fourier-transform infrared (FTIR) reflectometry and spreading resistance profiling (SRP). We demonstrate a high correlation between TZ thicknesses obtained from the optical modeling of FTIR reflectance spectra and SRP profiles. The dependence of TZ thickness change on the high-temperature annealing steps is also examined. FTIR reflectometry thus offers a quick, contactless alternative for obtaining structural parameters of an epitaxial layer, and these values can be well matched to those given by SRP.</p>","PeriodicalId":100109,"journal":{"name":"Applied Research","volume":"3 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/appl.202300146","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140087922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abraham Israel Calderón-Martínez, Omar Jiménez-Sandoval, Francisco Rodríguez-Melgarejo, Martín Adelaido Hernández-Landaverde, Francisco Javier Flores-Ruiz, Sergio Joaquín Jiménez-Sandoval
Cadmium telluride is an efficient light absorbing material successfully used in solar cell technology. The efficiency of such photovoltaic devices is strongly dependent on post-deposition thermal treatments in the presence of chlorine. The benefits of this process on the absorbing layer include removal of intragrain defects, grain growth enhancement, and grain boundaries passivation. The absorber chlorination is a crucial step for which CdCl2 is the most common choice. Its use, however, has been overshadowed by the toxicity of Cd- and Cl-containing vapors and residues. In this work, chlorine was incorporated in CdTe films during growth using sputtering targets with different chloride compounds: CdCl2, TeCl4, BaCl2, CaCl2, or LiCl. After characterizing these films, CdTe:CdCl2 and CdTe:TeCl4 were selected as feasible absorbers for testing their performance in photovoltaic devices. Efficiencies near 7% were obtained in as-grown unoptimized cells in which the absorber consisted of two layers: pristine CdTe and CdTe:CdCl2 or CdTe:TeCl4. The chlorinated layers acted as Cl sources for the adjacent CdTe and CdS, which produced a homogeneous distribution of chlorine throughout the cell. In the during-growth activating-layer (DG-AL) method used here, the chlorine diffusion during growth had a doping effect, passivated grain boundaries and defects, improved the back contact characteristics by reducing the CdTe work function, and lowered the pinhole formation probability by producing a compact chlorinated CdTe layer.
{"title":"Alternative during-growth chlorination of sputtered CdTe films and their implementation as activating layers in CdS/CdTe solar cells","authors":"Abraham Israel Calderón-Martínez, Omar Jiménez-Sandoval, Francisco Rodríguez-Melgarejo, Martín Adelaido Hernández-Landaverde, Francisco Javier Flores-Ruiz, Sergio Joaquín Jiménez-Sandoval","doi":"10.1002/appl.202300143","DOIUrl":"10.1002/appl.202300143","url":null,"abstract":"<p>Cadmium telluride is an efficient light absorbing material successfully used in solar cell technology. The efficiency of such photovoltaic devices is strongly dependent on post-deposition thermal treatments in the presence of chlorine. The benefits of this process on the absorbing layer include removal of intragrain defects, grain growth enhancement, and grain boundaries passivation. The absorber chlorination is a crucial step for which CdCl<sub>2</sub> is the most common choice. Its use, however, has been overshadowed by the toxicity of Cd- and Cl-containing vapors and residues. In this work, chlorine was incorporated in CdTe films during growth using sputtering targets with different chloride compounds: CdCl<sub>2</sub>, TeCl<sub>4</sub>, BaCl<sub>2</sub>, CaCl<sub>2</sub>, or LiCl. After characterizing these films, CdTe:CdCl<sub>2</sub> and CdTe:TeCl<sub>4</sub> were selected as feasible absorbers for testing their performance in photovoltaic devices. Efficiencies near 7% were obtained in <i>as-grown</i> unoptimized cells in which the absorber consisted of two layers: pristine CdTe and CdTe:CdCl<sub>2</sub> or CdTe:TeCl<sub>4</sub>. The chlorinated layers acted as Cl sources for the adjacent CdTe and CdS, which produced a homogeneous distribution of chlorine throughout the cell. In the during-growth activating-layer (DG-AL) method used here, the chlorine diffusion during growth had a doping effect, passivated grain boundaries and defects, improved the back contact characteristics by reducing the CdTe work function, and lowered the pinhole formation probability by producing a compact chlorinated CdTe layer.</p>","PeriodicalId":100109,"journal":{"name":"Applied Research","volume":"3 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/appl.202300143","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140421429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Siyuan Pang, Mahmoud A. Mahrous, Ana Carolina Constancio Trindade, Andrij Kozych, Nupur Kale, Waltraud M. Kriven, Iwona Jasiuk
Geopolymers (GPs) are emerging, low-density ceramic materials that are simple to manufacture, with high elastic modulus and strength, albeit with low toughness. Fiber reinforcements have been used to achieve varied ductile behaviors, but little is known about the GP addition to polymeric frame structures. Thus, drawing inspiration from the nanostructure of bones, this paper investigated an interpenetrating, co-continuous composite consisting of a GP as the stiff but brittle phase, and a 3D-printed polymer (PA12 White) as the soft and deformable phase. The composite mechanical properties and failure modes were studied experimentally using uniaxial compression and four-point bending tests. The co-continuous network constrained brittle cracking within the GP and reduced strain localization in the polymer. The results showed that the composite had higher strength (56.11 ± 2.12 MPa) and elastic modulus (6.08 ± 1.37 GPa) than the 3D-printed polymer and had higher toughness (5.98 ± 0.24 MJ/mm3) than the GP for the specific geometries examined. The shape effect study demonstrated that cubic structures had higher elastic modulus and strength but at the expense of lower toughness when compared to rectangular prism structures. The study of scale effects indicated that increasing the number of periodic unit cells while maintaining consistent bulk dimensions led to augmented strength and toughness, albeit without statistically significant alterations in elastic modulus. Thus, this paper presents an experimental realization of a novel, bio-inspired, interpenetrating, GP–polymer composite design, offering improved strength and toughness. It also provides valuable insights into the shape and size effects on the mechanical properties of this new composite.
{"title":"Mechanical behavior of bio-inspired composites made of co-continuous geopolymer and 3D-printed polymer","authors":"Siyuan Pang, Mahmoud A. Mahrous, Ana Carolina Constancio Trindade, Andrij Kozych, Nupur Kale, Waltraud M. Kriven, Iwona Jasiuk","doi":"10.1002/appl.202300097","DOIUrl":"10.1002/appl.202300097","url":null,"abstract":"<p>Geopolymers (GPs) are emerging, low-density ceramic materials that are simple to manufacture, with high elastic modulus and strength, albeit with low toughness. Fiber reinforcements have been used to achieve varied ductile behaviors, but little is known about the GP addition to polymeric frame structures. Thus, drawing inspiration from the nanostructure of bones, this paper investigated an interpenetrating, co-continuous composite consisting of a GP as the stiff but brittle phase, and a 3D-printed polymer (PA12 White) as the soft and deformable phase. The composite mechanical properties and failure modes were studied experimentally using uniaxial compression and four-point bending tests. The co-continuous network constrained brittle cracking within the GP and reduced strain localization in the polymer. The results showed that the composite had higher strength (56.11 ± 2.12 MPa) and elastic modulus (6.08 ± 1.37 GPa) than the 3D-printed polymer and had higher toughness (5.98 ± 0.24 MJ/mm<sup>3</sup>) than the GP for the specific geometries examined. The shape effect study demonstrated that cubic structures had higher elastic modulus and strength but at the expense of lower toughness when compared to rectangular prism structures. The study of scale effects indicated that increasing the number of periodic unit cells while maintaining consistent bulk dimensions led to augmented strength and toughness, albeit without statistically significant alterations in elastic modulus. Thus, this paper presents an experimental realization of a novel, bio-inspired, interpenetrating, GP–polymer composite design, offering improved strength and toughness. It also provides valuable insights into the shape and size effects on the mechanical properties of this new composite.</p>","PeriodicalId":100109,"journal":{"name":"Applied Research","volume":"3 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/appl.202300097","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140424707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sounik Manna, Rumi Mahata, Surya K. Dey, Angsuman Das Chaudhuri, Sujata M. Choudhury
The biggest obstacles in treating cancer with traditional chemotherapy are unpleasant side effects and drug resistance. A growing amount of interest has been exhibited in using aptamers as target ligands for targeted cancer therapy and specific cancer cell identification due to their distinct benefits. Aptamer-conjugated nano-materials have recently provided new prospects in cancer treatment with their improved therapeutic efficacy and capability of reducing toxicity. Consequently, they are not perceived as alien substances our body, which allows their comfortable acceptance. Several tumor markers such as nucleolin, mucin, and the epidermal growth factor receptor can be effectively recognized by aptamers. In addition, glycoproteins on the surface of tumor cells can be recognized using aptamers. So surface modification of drug by aptamer are accomplished for enhanced tumor-specific recognition by which drug-specific accretion, internalization, and drug retention in tumors increased through specific ligand-mediated interactions and thus therapeutic index is increased. Here, we highlight some promising classes of aptamer-conjugated nanoparticles for the specific recognition of cancer cells and targeted drug delivery and the molecular mechanism and immunomodulatory regulation of these aptamer have been focused.
{"title":"Multifunctional aptamer grafted targeted nano-drugs execute molecular cross-talks with cancer cells","authors":"Sounik Manna, Rumi Mahata, Surya K. Dey, Angsuman Das Chaudhuri, Sujata M. Choudhury","doi":"10.1002/appl.202300115","DOIUrl":"10.1002/appl.202300115","url":null,"abstract":"<p>The biggest obstacles in treating cancer with traditional chemotherapy are unpleasant side effects and drug resistance. A growing amount of interest has been exhibited in using aptamers as target ligands for targeted cancer therapy and specific cancer cell identification due to their distinct benefits. Aptamer-conjugated nano-materials have recently provided new prospects in cancer treatment with their improved therapeutic efficacy and capability of reducing toxicity. Consequently, they are not perceived as alien substances our body, which allows their comfortable acceptance. Several tumor markers such as nucleolin, mucin, and the epidermal growth factor receptor can be effectively recognized by aptamers. In addition, glycoproteins on the surface of tumor cells can be recognized using aptamers. So surface modification of drug by aptamer are accomplished for enhanced tumor-specific recognition by which drug-specific accretion, internalization, and drug retention in tumors increased through specific ligand-mediated interactions and thus therapeutic index is increased. Here, we highlight some promising classes of aptamer-conjugated nanoparticles for the specific recognition of cancer cells and targeted drug delivery and the molecular mechanism and immunomodulatory regulation of these aptamer have been focused.</p>","PeriodicalId":100109,"journal":{"name":"Applied Research","volume":"3 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/appl.202300115","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140448150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rita Höller, Katja Hrbinič, David Reisinger, Walter Alabiso, Stephan Schuschnigg, Mathias Fleisch, Christoph Waly, Elisabeth Rossegger, Sandra Schlögl
For the manufacture of extrusion dies, three-dimensional (3D) printing with photopolymers offers numerous advantages including flexibility, high surface quality, decent build speed, low costs and a reduced amount of waste. However, the majority of photocurable resins used in vat photopolymerization 3D printing rely on acrylates, which entail 3D-printed objects with poor mechanical properties. In particular, the high brittleness limits their application in rapid tooling, for which tough materials with high glass transition temperatures (Tg) are required. In the present study, we highlight the use of dual curable acrylate-epoxy resins with dynamic covalent bonds for the direct fabrication of extrusion dies. During digital light processing (DLP) 3D printing the acrylate network is formed, whose toughness and thermal stability are significantly enhanced by the thermoactivated formation of a second network. By following a postbaking procedure, aminoglycidiyl monomers are cured with an anhydride hardener bearing bulky norbornene groups yielding interpenetrating polymer networks with a Tg > 100°C. The tertiary amine groups present in the structure of the aminoglycidyl derivatives do not only accelerate the ring-opening reaction but also act as internal catalysts and activate bond exchange reactions between free –OH groups and ester moieties available in the photopolymer. This is confirmed by rheometer studies showing a distinctive stress relaxation at elevated temperature and giving rise to a possible reprocessability of the 3D-printed dies. With a selected resin formulation, a set of dies is printed by DLP 3D printing, with which a highly filled rubber compound is successfully extruded. The results clearly show that dual curable resins with dynamic covalent bonds are a promising class of material for rapid tooling and pave the way towards a customized and convenient fabrication of extrusion dies for rubber processing.
对于挤压模具的制造,使用光聚合物进行三维打印具有许多优势,包括灵活性、高表面质量、适当的构建速度、低成本和减少废料量。然而,大桶光聚合三维打印中使用的大多数光固化树脂都依赖于丙烯酸酯,这导致三维打印物体的机械性能较差。特别是,高脆性限制了它们在快速模具中的应用,而快速模具需要具有高玻璃化转变温度(Tg)的坚韧材料。在本研究中,我们重点介绍了使用具有动态共价键的双固化丙烯酸酯-环氧树脂直接制造挤压模具的方法。在数字光处理 3D 打印过程中,丙烯酸酯网络形成,通过热激活形成第二个网络,其韧性和热稳定性显著增强。通过后烘烤程序,氨基缩水甘油酯单体与带有大块降冰片烯基团的酸酐固化剂一起固化,形成互穿聚合物网络,Tg > 100°C。氨缩水甘油酯衍生物结构中的叔胺基团不仅能加速开环反应,还能充当内部催化剂,激活光聚合物中的游离 -OH 基团和酯分子之间的键交换反应。流变仪研究证实了这一点,该研究显示在温度升高时会出现明显的应力松弛,从而使 3D 打印模具具有可再加工性。利用选定的树脂配方,通过数字光处理三维打印技术打印出一套模具,并成功挤出了高填充度的橡胶复合物。研究结果清楚地表明,具有动态共价键的双固化树脂是一类很有前途的快速模具材料,并为定制和方便地制造橡胶加工挤出模具铺平了道路。本文受版权保护,保留所有权利。
{"title":"Rapid tooling for rubber extrusion molding by digital light processing 3D printing with dual curable vitrimers","authors":"Rita Höller, Katja Hrbinič, David Reisinger, Walter Alabiso, Stephan Schuschnigg, Mathias Fleisch, Christoph Waly, Elisabeth Rossegger, Sandra Schlögl","doi":"10.1002/appl.202300133","DOIUrl":"10.1002/appl.202300133","url":null,"abstract":"<p>For the manufacture of extrusion dies, three-dimensional (3D) printing with photopolymers offers numerous advantages including flexibility, high surface quality, decent build speed, low costs and a reduced amount of waste. However, the majority of photocurable resins used in vat photopolymerization 3D printing rely on acrylates, which entail 3D-printed objects with poor mechanical properties. In particular, the high brittleness limits their application in rapid tooling, for which tough materials with high glass transition temperatures (<i>T</i><sub>g</sub>) are required. In the present study, we highlight the use of dual curable acrylate-epoxy resins with dynamic covalent bonds for the direct fabrication of extrusion dies. During digital light processing (DLP) 3D printing the acrylate network is formed, whose toughness and thermal stability are significantly enhanced by the thermoactivated formation of a second network. By following a postbaking procedure, aminoglycidiyl monomers are cured with an anhydride hardener bearing bulky norbornene groups yielding interpenetrating polymer networks with a <i>T</i><sub>g</sub> > 100°C. The tertiary amine groups present in the structure of the aminoglycidyl derivatives do not only accelerate the ring-opening reaction but also act as internal catalysts and activate bond exchange reactions between free –OH groups and ester moieties available in the photopolymer. This is confirmed by rheometer studies showing a distinctive stress relaxation at elevated temperature and giving rise to a possible reprocessability of the 3D-printed dies. With a selected resin formulation, a set of dies is printed by DLP 3D printing, with which a highly filled rubber compound is successfully extruded. The results clearly show that dual curable resins with dynamic covalent bonds are a promising class of material for rapid tooling and pave the way towards a customized and convenient fabrication of extrusion dies for rubber processing.</p>","PeriodicalId":100109,"journal":{"name":"Applied Research","volume":"3 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/appl.202300133","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140451219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xavier Allonas, Ben Hammouda, Boris Métral, Emile Goldbach, Anne-Sophie Schuller, Christian Ley, C.Céline Croutxé-Barghorn
Today, controlling the photopolymerization process during the 3D printing in vat photopolymerization is a key challenge. In this work, it is shown that using a relatively limited set of parameter, it is possible to estimate key factors involved in such process. On the basis of 16 formulations containing different concentrations of photoinitiator and UV filter, attempt was made to rationalize the photonic parameters used in the 3D printing process, that is, the depth of penetration Dp and the critical energy Ec. It is shown that the experimental Dp values can be correlated with calculated ones from Bouguer–Beer–Lambert law. Real-time Fourier-transform infrared spectroscopy (RT-FTIR) experiments were performed under similar conditions as in 3D printing. The conversion profiles were used to estimate the Ec values. The limits of this approach was discussed as a function of the UV filter concentration. Finally, the RT-FTIR curves are exploited to predict the in-depth conversion of the different 3D printed layers and compared to experimental results obtained by confocal Raman microscopy.
如今,在大桶光聚合 3D 打印过程中控制光聚合过程是一项关键挑战。这项研究表明,使用一组相对有限的参数,就有可能估算出此类过程中涉及的关键因素。根据含有不同浓度光引发剂和紫外线过滤器的 16 种配方,尝试对 3D 打印过程中使用的光子参数(即穿透深度 Dp 和临界能量 Ec)进行合理化。实验结果表明,实验得出的 Dp 值与根据布格-比尔-朗伯定律计算得出的 Dp 值具有相关性。实时傅立叶变换红外实验是在与 3D 打印类似的条件下进行的。转换曲线用于估算 Ec 值。讨论了这种方法的局限性与紫外线滤光片浓度的函数关系。最后,利用 RT-FTIR 曲线预测了不同 3D 打印层的深度转换,并与共焦拉曼显微镜获得的实验结果进行了比较。本文受版权保护。
{"title":"Controlling photopolymerization reaction in layer-by-layer photopolymerization in 3D printing","authors":"Xavier Allonas, Ben Hammouda, Boris Métral, Emile Goldbach, Anne-Sophie Schuller, Christian Ley, C.Céline Croutxé-Barghorn","doi":"10.1002/appl.202400004","DOIUrl":"10.1002/appl.202400004","url":null,"abstract":"<p>Today, controlling the photopolymerization process during the 3D printing in vat photopolymerization is a key challenge. In this work, it is shown that using a relatively limited set of parameter, it is possible to estimate key factors involved in such process. On the basis of 16 formulations containing different concentrations of photoinitiator and UV filter, attempt was made to rationalize the photonic parameters used in the 3D printing process, that is, the depth of penetration <i>Dp</i> and the critical energy <i>Ec</i>. It is shown that the experimental <i>Dp</i> values can be correlated with calculated ones from Bouguer–Beer–Lambert law. Real-time Fourier-transform infrared spectroscopy (RT-FTIR) experiments were performed under similar conditions as in 3D printing. The conversion profiles were used to estimate the <i>Ec</i> values. The limits of this approach was discussed as a function of the UV filter concentration. Finally, the RT-FTIR curves are exploited to predict the in-depth conversion of the different 3D printed layers and compared to experimental results obtained by confocal Raman microscopy.</p>","PeriodicalId":100109,"journal":{"name":"Applied Research","volume":"3 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/appl.202400004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139960555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Intelligent packaging has attracted research interest during the last decades. More specifically, food packaging is of great importance due to the utmost need to monitor and maintain food quality until consumption. Thus, there is a high demand for sensors capable of detecting gases such as CO2, emitted by packaged meat or chicken which serve as freshness indicators. In the present work, a sensor based on Cu2O nanocubes was fabricated and tested against CO2 at room temperature. Cu2O nanocubes were synthesized by solution-based methods and deposited on commercial interdigitated electrodes. Specifically, the Cu2O-based sensor successfully detected down to 5% CO2 (50,000 ppm) in the ambient atmosphere, at room temperature, with a response time of less than 90 s. This level of CO2 is in the range that indicates the unsuitability of packaged meat for consumption. Furthermore, the sensor was able to maintain its response to CO2 after being stored in the fridge for 20 days, showcasing its endurance under food maintenance conditions.
{"title":"Cu2O nanocubes as gas sensing elements for food packaging applications","authors":"Emmanouil Gagaoudakis, Angelliki Sfakianou, Eleni Mantsiou, Vassilios Binas","doi":"10.1002/appl.202300125","DOIUrl":"10.1002/appl.202300125","url":null,"abstract":"<p>Intelligent packaging has attracted research interest during the last decades. More specifically, food packaging is of great importance due to the utmost need to monitor and maintain food quality until consumption. Thus, there is a high demand for sensors capable of detecting gases such as CO<sub>2</sub>, emitted by packaged meat or chicken which serve as freshness indicators. In the present work, a sensor based on Cu<sub>2</sub>O nanocubes was fabricated and tested against CO<sub>2</sub> at room temperature. Cu<sub>2</sub>O nanocubes were synthesized by solution-based methods and deposited on commercial interdigitated electrodes. Specifically, the Cu<sub>2</sub>O-based sensor successfully detected down to 5% CO<sub>2</sub> (50,000 ppm) in the ambient atmosphere, at room temperature, with a response time of less than 90 s. This level of CO<sub>2</sub> is in the range that indicates the unsuitability of packaged meat for consumption. Furthermore, the sensor was able to maintain its response to CO<sub>2</sub> after being stored in the fridge for 20 days, showcasing its endurance under food maintenance conditions.</p>","PeriodicalId":100109,"journal":{"name":"Applied Research","volume":"3 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/appl.202300125","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139962228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carbon nanotubes (CNTs) have attracted interest for optoelectronic applications due to their unique electronic and optoelectronic properties. In particular, multiwall (MW) CNTs film acts as perfect photo-collector surface with the possibility to tune the absorbance by controlling the film thickness. In this work, we demonstrate two types of hybrid Si-MWCNTs photodetectors. The MWCNTs are solution-processed and deposited on n-silicon substrate covered by two different dielectrics (Si3N4 or SiO2). The MWCNTs/SiO2/n-Si device is used here as reference, since the SiO2/Si system is the most widely investigated structure in microelectronics. The electrical and optical characteristics of the reference device are compared with the corresponding of our basic MWCNTs/Si3N4/n-Si device. The MWCNTs are deposited on the substrate with the drop casting technique. Optical performance of the SiO2 device is comparable to the Si3N4 device thus revealing a quite interesting response under UV illumination. The Si3N4 device exhibited a peak equivalent quantum efficiency (EQE) of 57% at 3 μW of source illumination power, thus demonstrating a superior performance as compared to the SiO2 device (EQE of up to 55%, which is also promising for future applications). This performance can be attributed to the great absorption in UV region of CNTs layer. Apart from this technological goal, we also investigated how MWCNTs/Si3N4 or MWCNTs/SiO2 heterojunctions perform using standard electrical characterization techniques and how the presence of the CNTs change the dielectric characteristics of both substrates.
{"title":"Optimizing fabrication and performance of liquid-processed carbon nanotube photodetectors on various substrates","authors":"Vasileios Lionas, Dimitrios Velessiotis, George Pilatos, Konstantinos Giannakopoulos, Aristotelis Kyriakis, Nikolaos Glezos, Dimitrios Skarlatos","doi":"10.1002/appl.202300121","DOIUrl":"10.1002/appl.202300121","url":null,"abstract":"<p>Carbon nanotubes (CNTs) have attracted interest for optoelectronic applications due to their unique electronic and optoelectronic properties. In particular, multiwall (MW) CNTs film acts as perfect photo-collector surface with the possibility to tune the absorbance by controlling the film thickness. In this work, we demonstrate two types of hybrid Si-MWCNTs photodetectors. The MWCNTs are solution-processed and deposited on n-silicon substrate covered by two different dielectrics (Si<sub>3</sub>N<sub>4</sub> or SiO<sub>2</sub>). The MWCNTs/SiO<sub>2</sub>/n-Si device is used here as reference, since the SiO<sub>2</sub>/Si system is the most widely investigated structure in microelectronics. The electrical and optical characteristics of the reference device are compared with the corresponding of our basic MWCNTs/Si<sub>3</sub>N<sub>4</sub>/n-Si device. The MWCNTs are deposited on the substrate with the drop casting technique. Optical performance of the SiO<sub>2</sub> device is comparable to the Si<sub>3</sub>N<sub>4</sub> device thus revealing a quite interesting response under UV illumination. The Si<sub>3</sub>N<sub>4</sub> device exhibited a peak equivalent quantum efficiency (EQE) of 57% at 3 μW of source illumination power, thus demonstrating a superior performance as compared to the SiO<sub>2</sub> device (EQE of up to 55%, which is also promising for future applications). This performance can be attributed to the great absorption in UV region of CNTs layer. Apart from this technological goal, we also investigated how MWCNTs/Si<sub>3</sub>N<sub>4</sub> or MWCNTs/SiO<sub>2</sub> heterojunctions perform using standard electrical characterization techniques and how the presence of the CNTs change the dielectric characteristics of both substrates.</p>","PeriodicalId":100109,"journal":{"name":"Applied Research","volume":"3 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/appl.202300121","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139838172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}