{"title":"Preparation of magnetic scaffolds via supercritical carbon dioxide foaming process using iron oxide nanoparticles coated with CO2-philic materials as nucleating agents","authors":"Zhen Jiao, Shuo Zhang, Jinjing Wang, Yi Zhang","doi":"10.1002/app.56256","DOIUrl":"10.1002/app.56256","url":null,"abstract":"<p>The iron oxide nanoparticles (IONs), coated with different materials, are synthesized and utilized as nucleating agents to prepare magnetic multi-modal porous scaffolds of poly (lactic-<i>co</i>-glycolic acid)/IONs using the supercritical carbon dioxide (ScCO<sub>2</sub>) foaming process. The effects of the modification materials, including citric acid, polycaprolactone, and polyvinyl acetate, on the foaming process and properties of the magnetic scaffolds are systematically investigated. The results indicate that the solubility and diffusion ability of CO<sub>2</sub> in the foaming materials played a vital role in the foaming process. The use of CO<sub>2</sub>-philic materials and high pressure proves beneficial in generating micropores. The scaffolds with multi-modal porous structures can be obtained at relatively low pressure for the ScCO<sub>2</sub> foaming systems evaluated in this study. Furthermore, the prepared scaffolds exhibit high porosity and a good compressive modulus (higher than 0.4 MPa), satisfying the requirements of tissue engineering for soft tissue scaffolds.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 47","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Murtaza Haider Syed, Md Maksudur Rahman Khan, Mior Ahmad Khushairi Mohd Zahari, Mohammad Dalour Hossen Beg, Norhayati Abdullah
{"title":"Optimization of solvent system for chitosan/polylactic acid/nanocellulose nanofibers using needleless electrospinning","authors":"Murtaza Haider Syed, Md Maksudur Rahman Khan, Mior Ahmad Khushairi Mohd Zahari, Mohammad Dalour Hossen Beg, Norhayati Abdullah","doi":"10.1002/app.56291","DOIUrl":"10.1002/app.56291","url":null,"abstract":"<p>Needless electrospinning (NES) is the most advanced and robust method to generate biopolymeric nanofibers. NES overcomes the needle clogging and low throughput issues of conventional needle based electrospinning (ES). However, the issue with all ES techniques is the absence of generalized methods in the literature, and most of the work is being done empirically. The solvent system dictates the feasibility of the ES process, and solvent system based studies can help create more generalized ES methods. The current work provides a systematic approach to fabricating tribiopolymeric nanofibers. NES was used to fabricate chitosan (CS)/polylactic acid (PLA)/nanocellulose (NCC) based nanofibers by optimizing the solvent system using dichloromethane (DCM) and trifluoroacetic acid (TFA). Biopolymeric blend PLA/CS/NCC (10:0.1:0.05 w/v %) in various formulated solvent systems were made and analyzed for their physical properties (sedimentation rate, particle size, viscosity, and surface tension) and subjected to NES. The binary solvent system SS91 (DCM (90):TFA (10) %) showed the lowest sedimentation rate and viscosity while the highest particle size and surface tension, resulting in the beads free nanofibers. The viscosity and surface tension comparison were used to determine a critical point for the feasibility of nanofiber fabrication. Overall, the study showed a systematic approach for fabricating complex tri-biopolymeric nanofibers in future.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 48","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hao Wu, Dengwang Lai, Mengyao Nan, Wuyan Cao, Li Liu, Yuejun Liu, Jun Yang
{"title":"Flame retardant polyvinyl alcohol film with self-releasing carbon dioxide and ammonia from phytic acid and urea","authors":"Hao Wu, Dengwang Lai, Mengyao Nan, Wuyan Cao, Li Liu, Yuejun Liu, Jun Yang","doi":"10.1002/app.56258","DOIUrl":"10.1002/app.56258","url":null,"abstract":"<p>This paper utilizes the reaction of phytic acid (PA) and urea (UM) in polyvinyl alcohol (PVA) solution to synthesize flame retardant gasses (CO<sub>2</sub>, NH<sub>3</sub>) for the preparation of PVA composite films containing flame retardant microbubbles. The flame retardancy of PVA composite films was assessed using methods including limiting oxygen index (LOI), vertical burning (UL 94), and cone calorimetry. The results indicated an increase in the LOI of the PVA composite film containing flame retardant microfoam from 20% to 30% compared with the pure PVA film, and that UL 94 reached VTM-0. Furthermore, its peak exothermic rate and total exothermic amount were reduced by 36.25% and 38.92%, respectively, compared with the pure PVA film. The investigation of the flame-retardant mechanism employed thermogravimetric-infrared (TG-IR), scanning electron microscopy (SEM), Raman spectroscopy, and infrared spectroscopy. The results demonstrate that the CO<sub>2</sub> and NH<sub>3</sub> flame retardant microbubbles within the composite film render it less ignitable at the initial stage, and that the internal UM of the composite film continues to decompose, releasing CO<sub>2</sub> and NH<sub>3</sub> upon heating. In addition, the acidic substances decomposed by PA during combustion promote the dehydration, cross-linking, and cyclization of PVA, generating chemical structures such as P<span></span>O<span></span>C, P<span></span>O<span></span>P, and PO<sub>4</sub> with enhanced thermal stability. This encourages the formation of a continuous, dense charcoal layer and impedes the transfer of oxygen and heat into the interior.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 47","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Catalytic pyrolysis upcycling of waste thermosetting epoxy resin into fire-retardant additive","authors":"Roya Mahmoodi, Omid Zabihi, Mojtaba Ahmadi, Mahmoud Reza Ghandehari Ferdowsi, Minoo Naebe","doi":"10.1002/app.56271","DOIUrl":"10.1002/app.56271","url":null,"abstract":"<p>This research introduces a low-temperature catalytic-assisted pyrolysis method for recycling waste thermosetting epoxy resins, transforming them into an efficient fire-retardant additive for new epoxy resin formulations. In this study, we demonstrate that boric acid (BA) can significantly reduce the temperature required for epoxy resin (EP) pyrolysis, resulting in degradation products containing boron atoms that can act as a fire-retardant additive. The impact of 5%–20% content of recycled EP (R-EP) on the curing process, thermal stability, fire retardancy, and mechanical properties of the new EP was comprehensively investigated. The TGA results show that adding BA to epoxy resin at a 1:4 BA:EP ratio significantly reduces pyrolysis temperature. Neat EP degrades in two stages in 341°C and 557°C, while EP with BA degrades in three stages, starting below 120°C and peaking around 142°C. The results demonstrated an outstanding effect of incorporating 20% R-EP on the char formation and fire retardancy of the new EP, surpassing the performance of 20% triphenyl phosphate (TPP), a commercially available fire retardant. The storage modulus for neat EP is 1510 MPa, increasing to 2280 MPa with EP/R-EP 20%, indicating enhanced rigidity. Addition of R-EP raised glass transition temperature (<i>T</i><sub>g</sub>) of the epoxy resin up to 38°C, indicating highly cross-linked structures compared to TPP-modified EP, which shows lower <i>T</i><sub>g</sub> values.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 47","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/app.56271","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuejiao Wu, Jian Yang, Ke Shen, Liyan Liu, Jing Cao, Zhaomei Wang
{"title":"Novel amphiphilic rhamnogalacturonnan I-based nanomicelles for targeted delivery of curcumin to hepatocellular carcinoma cells","authors":"Yuejiao Wu, Jian Yang, Ke Shen, Liyan Liu, Jing Cao, Zhaomei Wang","doi":"10.1002/app.56264","DOIUrl":"10.1002/app.56264","url":null,"abstract":"<p>Curcumin (Cur) is a bioactive nutraceutical with great potential in biological, nutritional, and medical applications. However, these applications are limited by various factors such as insufficient ingestion, low aqueous solubility, and relatively high toxicity to normal cells. To tackle these obstacles, we synthesized a novel Cur-modified-rhamnogalacturonan (RG-C) nano-micelle carrier to target-deliver Cur to hepatocellular carcinoma HepG2 cells via specific recognition of RG-I by the overexpressed surface galactin-3 receptor. Fourier transfer infrared, UV–vis, and <sup>1</sup>H NMR analyses confirmed the conjugation between RG and Cur RG-C loaded with Cur (RG-CC) was formed via self-assembly in an aqueous solution with a drug loading efficiency of 12.2%. RG-CC micelle was ellipsoidal or cubic with a size ranging between 100 and 200 nm by scanning electron microscopy observation. Cur release from RG-CC exhibited a controlled and pH-dependent manner with 50% at pH 5.0 in contrast to 5% at pH 7.4 after 24 h exposure. RG-CC possessed more potent anti-proliferative activity against HepG2 cells than normal embryonic kidney 293T cells. Compared to free Cur, both the anti-proliferative effect and uptake of RG-CC were significantly higher in HepG2 cells as revealed from laser confocal microscopy and flow cytometry analyses. RG-CC was a promising anticancer candidate and deserves further preclinical and clinical investigations.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 47","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Enhanced rheological, crystallization, mechanical, and heat resistance performance of poly(L-lactide)/basalt fibers composites via in situ formation of stereocomplex polylactide crystals","authors":"Hongda Cheng, Lijuan Wang, Changyu Han","doi":"10.1002/app.56280","DOIUrl":"10.1002/app.56280","url":null,"abstract":"<p>Due to its favorable mechanical strength, transparency, and biocompatibility, polylactic acid (PLA) has considerable potential as a biodegradable material. Nevertheless, developing high-performance PLA composites through environmentally friendly and cost-effective methods remains a significant challenge. In this study, the composites comprising poly(L-lactide) (PLLA), basalt fibers (BFs), and poly(D-lactide) (PDLA) are prepared through facile melt blending. The in situ formed stereocomplex polylactide (SC-PLA) crystals improve the crystallization ability and rheological behavior of PLLA/BF/PDLA composites. Upon adding 5 wt% PDLA, BFs are nicely dispersed in PLLA matrix because of increased shear intensity. The synergistic effect of BFs and SC-PLA crystals enhances the mechanical, thermomechanical, and heat resistance properties of PLLA. In particular, PLLA/BF/10%PDLA composites exhibit a Vicat Softening Temperature (VST) of 155.5°C, increasing by approximately 100°C over neat PLLA. Annealing treatment increases the Young's modulus, thermomechanical properties, and VST of samples while reducing their tensile strength. Interestingly, the tensile strength of the annealed PLLA/BF/10%PDLA composites is 50.2 MPa, twice that of the annealed neat PLLA due to the introduction of SC-PLA crystals. Simultaneously improving the rheological, mechanical, and heat resistance performance of PLLA opens possibilities for expanding its potential applications in the industrial field.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 48","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Preparation and antimicrobial properties of Ag+/carboxymethyl chitosan/silk fibroin composite microspheres","authors":"Xiaofei Yan, Zhaoyang Gao, Yehua Shao, Dongming Qi, Bei Wu, Shirong Guo","doi":"10.1002/app.56277","DOIUrl":"10.1002/app.56277","url":null,"abstract":"<p>The frequent occurrence of respiratory infectious diseases has made it difficult for traditional antibacterial materials to meet practical needs in recent years. There was an urgent need to develop new antimicrobial materials with stronger antimicrobial effects and biosafety. In this paper, the carboxymethyl chitosan (CMCTS)/silk fibroin (SF) composite microspheres were synthesized through self-assembly, and the Ag<sup>+</sup>/CMCTS/SF composite microspheres were prepared by loading the Ag<sup>+</sup> onto their surface. It investigated the effect of CMCTS contents, SF on the size and secondary structure of CMCTS/SF composite microspheres, and the antibacterial activity and mechanism of Ag<sup>+</sup>/CMCTS/SF composite microspheres. The results showed that the average particle size distribution size of CMCTS/SF composite microspheres was ranged from approximately 593–1115 nm. When CMCTS was added at 50 wt%, the content of <i>β</i>-sheet structures in silk fibroin microspheres was the largest at 38.6%. And the CMCTS/SF composite microspheres loaded with Ag<sup>+</sup> enhanced the bactericidal rate against <i>Escherichia coli</i> and <i>Staphylococcus aureus</i> by 27.51% and 36.39%, respectively. In addition, the Ag<sup>+</sup>/CMCTS/SF composite microspheres have high biological safety, providing a new method for designing an efficient, green, and safe composite antibacterial agent.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 47","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jin Yang, Yixuan Hou, Yingzheng Hong, Yingbang Yao
{"title":"Surface modification of h-BN and electric field control of its orientation in sulfonated polyetheretherketone","authors":"Jin Yang, Yixuan Hou, Yingzheng Hong, Yingbang Yao","doi":"10.1002/app.56255","DOIUrl":"10.1002/app.56255","url":null,"abstract":"<p>Since thermally conductive fillers easily aggregate when introduced into polymer matrix, it is essential to apply a modifier to enhance the dispersion of the filler. In current study, the surface of boron nitride (h-BN) is firstly modified by employing a double modification process and then added into sulfonated polyetheretherketone (SPEEK) to form the composite materials. Four different kinds of samples of double-modified h-BN were obtained. Ultimately, the XXX@h-BN/SPEEK (XXX denoted as modifier, i.e. PDA, VTMS, TEOS, and APS) flexible film with the horizontally oriented XXX@h-BN was produced by heating the mixture under an external electric field. The test results indicate that the thermally conductive filler PDA@h-BN (PDA: polydopamine), which was prepared by modifying OH@h-BN with PDA, loaded into SPEEK, and electrically oriented, shows the best overall performances. With a high tensile strength of 43.24 MPa and good flexibility, PDA@h-BN/SPEEK flexible film exhibits an in-plane thermal conductivity of 2.3 Wm<sup>−1</sup> K<sup>−1</sup> at a filling ratio of 10 wt%. The sample may be bent at a steep angle without breaking down and can recover to original shape bearing its high degree of flexibility.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 47","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Evaluation of cell adhesion and inflammatory response of chitin and chitosan nanofibers patterned by inkjet printing","authors":"Tetsuya Katuragawa, Yoshikuni Teramoto","doi":"10.1002/app.56285","DOIUrl":"10.1002/app.56285","url":null,"abstract":"<p>Chitin and chitosan nanofibers (ChNF and CtsNF) are promising biomaterials due to their biocompatibility, biodegradability, and non-toxicity. This study investigates the cell adhesion properties and inflammatory responses of CtsNF, ChNF, and their mixtures when patterned on cellophane films using inkjet printing technology, keeping in mind their potential applications as cell culture scaffolds. The viscosities of 0.1 wt% aqueous dispersions of CtsNF, ChNF, and their mixtures were confirmed to be suitable for inkjet printing. Microstructures with varying thicknesses were fabricated by adjusting the printing parameters. Mouse fibroblast cells (L929) and mouse macrophages (RAW264.7) were used to evaluate cell adhesion and inflammatory responses. The results demonstrated that CtsNF microstructures exhibited excellent cell adhesion even for those as thin as ~140 nm and low inflammatory potential. This finding provides valuable insights into the development of advanced biomaterials for medical applications and could be instrumental in optimizing dosage settings for wound healing treatments as well.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 48","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Boron nitride nanosheets synergized with two-dimensional micron silver sheets to enhance thermal conductivity and insulation of epoxy resin composites","authors":"Wenchao Zhang, Yutong Xiao, Yuan Liang, Qingguo Chen, Dong Yue, Yu Feng","doi":"10.1002/app.56293","DOIUrl":"10.1002/app.56293","url":null,"abstract":"<p>With the rapid progress of the advanced electronic device industry, precision electronic instruments are gradually developing towards miniaturization. In this case, epoxy resin gradually attracts people's attention, but its intrinsic thermal conductivity is not high, and the resulting heat dissipation problem limits the further application of epoxy resin in the field of electronic packaging. Therefore, how to enhance the thermal conductivity of epoxy resins has become an urgent problem in the field of electronic packaging. In this work, BNNS was successfully prepared by stripping h-BN into a flaky two-dimensional material, which was added to the epoxy resin as a filler to make the composite material. And on the basis of the above, two-dimensional micron silver flakes (AgMS) with different mass fractions were added to the composites, and the AgMS/BNNS/EP composites were successfully prepared. When BNNS was 25 wt% and AgMS was 1 wt%, its out-of-plane thermal conductivity was enhanced from 0.17 W m<sup>−1</sup> K<sup>−1</sup> of pure epoxy resin to 0.43 W m<sup>−1</sup> K<sup>−1</sup>. When BNNS was 20 wt% and AgMS was 1 wt%, the breakdown strength was enhanced from 105 kV/mm for pure epoxy to 130 kV/mm. This work provides a new strategy for synthesizing high-thermal-conductivity epoxy matrix composites.</p>","PeriodicalId":183,"journal":{"name":"Journal of Applied Polymer Science","volume":"141 48","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}