Advanced Industrial and Engineering Polymer Research最新文献

Additive Manufacturing (AM) has been a noticeable technology and made significant progress since the late 1980s. Despite the tremendous growth, this technology is still facing numerous manufacturing challenges. AM of structures and smart materials such as shape memory polymers and alloys is one of the most actively researched areas in which printed objects can alter their properties and shape when exposed to a stimulus e.g., light, temperature, magnetic fields, pH, and humidity. The AM-build parts which can take advantage of these shape-changing features, lead to the growth of 4D printing by introducing time as a fourth dimension in AM processes. This new field originated in 2013, and since then, it has generated great interest due to its potential to build innovative, multi-functional, self-assembling, and self-repairing components with modifiable properties, shapes, and functionalities. This review article intends to examine the major developments of 4D printing in the biomedical field. The study will provide an overview of various 4D printing technologies including vat photo-polymerization, extrusion-based methods, and material jetting and their uses in the biomedical field. It focuses on smart materials like SMPs, LCEs, SMPAs, etc., and their applications in various industries e.g., mechanical, biomedical, aerospace, etc., and explores external stimuli such as moisture, temperature, pH, magnetic fields, and light. The article delves into the promising applications of 4D printing in biomedical fields such as drug delivery, orthopedics, medical devices, tissue engineering, and dentistry and analyzes the challenges associated with 4D printing in the biomedical field, and suggests the future directions including optimization of printing parameters, and exploration of novel materials to broaden its applications.

Bacterial nanocellulose (BNC), as a natural polymer, produced in vivo by bacteria and in vitro by the cell-free enzymes system, is comprised of nano-sized fibers. The pristine BNC possesses unique structural, physiological, and biological properties. Its fibrous and porous morphology allows the incorporation of natural and synthetic polymers, nanomaterials, clays, etc., while the presence of free hydroxyl (OH) groups allows its chemical modification with a variety of functional groups to form nanohybrids. These hybrids not only have superior properties to those of pristine BNC but possess additional functionalities imparted by the reinforcement materials. The properties of BNC-based nanohybrids can be tuned at macro, micro, and nano-scales as well as controlled at molecular levels. This review consolidates the current knowledge on the synthesis of β-(1,4)-glucan chains, their excretion and organization into high-ordered nano-sized fibers, as well as functionalization, both at physiological and molecular levels. It comparatively discusses the microbial and cell-free synthesis of cellulose and discusses the potential merits and limitations of each method. It further explores the methods used for developing BNC-based hybrids and discusses the synthesis-structure-properties relationship of BNC-based hybrids to justify their use for targeted biotechnological applications. A large portion of this review is devoted to discussing the recent trends in the preparation of BNC-based nanohybrids for their biotechnological applications, including biomedical (i.e., wound healing, cardiovascular devices, neural tissues, bone and cartilage tissues, dental implants, and drug delivery) and non-biomedical (biosensing, cosmetics, food, bio- and optoelectronics, environment, energy, and additive manufacturing). Finally, it provides an outlook on the future BNC research for human welfare.

Graphene has unusual physical properties such as high thermal and electrical conductivity, high elasticity, and unique optical properties, making it suitable for a variety of biomedical applications in biosensing and drug delivery. Nanostructures of graphene and graphene derivatives have been fabricated and applied to different types of biosensors. In this article, we have reviewed recent advances in the fabrication of graphene-and graphene-derivatives-based nanomaterials, with a particular focus on green processes for producing bio-based graphene nanostructures. The various methods used to synthesize a few layers of graphene sheets, including the top-down and bottom-up approaches, have been thoroughly discussed. The benefits of using those green processes and current challenges are analyzed. We also discussed the applications of these nanomaterials in biomedical sensors. Current reviews for graphene-based nanostructures in biomedical sensors provide brief summaries of current technologies. We have reviewed current state-of-the-art graphene-based biosensors and provided an in-depth summary of their working mechanism and use of graphene nanomaterials to enhance their sensitivities. We have grouped these sensors based on their working principles, such as optical and electrochemical sensors for detecting and quantifying a variety of biomolecules and cells. The performance of the graphene nanomaterial-based biosensors have been compared with conventional biosensing techniques, and their pros and cons are discussed. We concluded the article by summarizing our findings, discussing current challenges, and outlining the future directions of using graphene-based nanostructures for biosensing applications.

Chitosan is obtained from chitin, which is abundantly found in crustaceans and obtained through various methods. The demineralization, deproteinization, discoloration, and deacetylation of chitin produce chitosan consisting of d-glucosamine and N-acetyl d-glucosamine units that are linked through β-(1,4)-glycosidic linkages. Chitosan has gained significant attention in the biomedical field due to its unique properties such as abundance, renewability, non-toxic nature, antimicrobial activity, biodegradability, and polyfunctionality. One of its key properties is its antimicrobial activity, which is why it has been heavily utilized in the biomedical field. To provide a comprehensive overview of chitosan, this review discusses its extraction from chitin and its properties based on its source and extraction methods. It also delves into various chemical modifications and nanocomposite development using natural and synthetic materials. The review emphasizes the multitude of properties that make chitosan an excellent choice for a wide range of biomedical applications. It discusses various mechanisms of antibacterial activity and the factors affecting this activity. Additionally, the review highlights biodegradability, hemocompatibility, antioxidant activity, anti-inflammation, and other properties of chitosan that contribute to its suitability for different biomedical applications, including wound dressing materials, drug delivery carriers, biosensing and diagnostic devices, bone substitutes, and bioimaging. While discussing some limitations of chitosan, the review concludes with an overview of the future perspective for developing multifunctional chitosan-based nanomaterials that could potentially move from laboratory to clinical trials for treating various diseases.

Recent advancements in nanostructured materials have found widespread application across many domains, particularly in the biomedical field. Before using nanostructured materials in clinical applications, many important challenges, especially those related to their uses in biomedicine, must be resolved. Biological activity, compatibility, toxicity, and nano-bio interfacial characteristics are some of the major problems in biomedicine. We may therefore investigate the nanostructured materials for biomedical applications with the aid of modern characterization techniques. This overview article illustrates the present state of nanostructured materials in the biomedical field with uses and the importance of characterization methods through the use of cutting-edge characterization techniques. In this article, the techniques for analysing the topology of nanostructures, including Field Emission Scanning Electron Microscopy (FESEM), Dynamic Light Scattering (DLS), Scanning Probe Microscopy (SPM), Near-field Scanning Optical Microscopy (NSOM), and Confocal microscopy, are described. In addition, the internal structural investigation techniques X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), and Magnetic Resonance Force Microscopy (MRFM) are discussed. In addition, composition analysis techniques such as X-ray Photoelectron Spectroscopy (XPS), Energy Dispersive X-ray spectroscopy (EDS), Auger Electron Spectroscopy (AES), and Secondary Ion Mass Spectroscopy (SIMS) have been discussed. The essence of the nanomaterials as they relate to physics, chemistry, and biology is thoroughly explained in this overview along with characterization techniques through case studies. Additionally, the constraints and difficulties with specimen and analysis that are related to comprehending nanostructured materials have been identified and addressed in this study.

Injection moulded specimens were produced from biodegradable poly(butylene succinate) (PBS)/organomodified montmorillonite (OMMT) nanocomposites, after melt compounding in different compositions. WAXD studies demonstrated that the OMMT formed similar intercalation levels in the 2.5–10 w/w% additive ratio range. It was also proved by rotational rheometry that the nanoclay stacks form physical network above 5 w/w% concentration, which significantly influence the viscoelastic properties of the melt. The value of zero shear viscosity also changed accordingly, starting to increase above 5 w/w% nanoclay content. The OMMT content reduced the creep sensitivity measured in molten state.

X-ray and DSC investigations showed that OMMT inhibits the crystallisation of PBS, resulting in a decrease in crystallinity at higher nanoclay ratios. As a result, the room temperature creep increased with the OMMT ratio.

The Young's modulus linearly increases in the entire concentration range exceeding 1.2 GPa at 10 w/w% nanoclay content. The value of yield strength does not change significantly (35–40 MPa), but the strain at yield – which characterises stiffness – and the notched Izod impact strength already decrease at 2.5 w/w% OMMT content, but further increasing the nanoclay content has minor effect. However, the nanocomposite with 10 w/w% OMMT can be a real alternative to polypropylene (PP) and high-density polyethylene (HDPE) injection moulded products based on its mechanical properties.

To characterise the effect of OMMT on dynamic mechanical properties, the S (Stiffening effectiveness), L (Loss effectiveness) and D (Damping effectiveness) indices were introduced to quantitatively describe the nanoclay effect intensity in each temperature range.

Biopolymers from renewable bio-based resources provide a sustainable alternative to petroleum-derived plastics, but limitations like brittleness and cost restrict applicability. Blending offers an affordable route to combine the advantages of different biopolymers for tailored performance. However, most biopolymer pairs are intrinsically immiscible, necessitating compatibilization to obtain optimal blend morphology, interfacial interaction, and properties. This review summarizes key compatibilization strategies and recent advances in tailoring biopolymer blends. Non-reactive techniques using block or graft copolymers can increase compatibility, though property enhancements are often modest. More impactful are reactive methods, which functionalize and form compatibilizing copolymers in-situ during melt-blending. Nanoparticle incorporation also effectively compatibilizes through interface localization and morphology control. These strategies enable significant toughening and compatibilization of poly(lactic acid) (PLA) and other brittle biopolyesters by blending with ductile polymers such as poly(butylene adipate-co-terephthalate)((PBAT) or elastomers like natural rubber. Properly compatibilized PLA blends exhibit major simultaneous improvements in elongation, strength, and impact resistance. Using inexpensive starch decreases cost but requires compatibilization to maintain adequate properties. Nanoparticles additionally impart functionality like barrier and flame retardance. However, quantitatively correlating interaction, processing, morphology, and properties will enable further blend optimization. Developing tailored reactive chemistries and nanoparticles offers potential beyond conventional techniques, and retaining biodegradability is also crucial. Overall, compatibilization facilitates synergistic property combinations from complementary biopolymers, providing eco-friendly, high-performance, and cost-effective alternatives to traditional plastics across diverse applications.

In recent decades, demand for sustainable materials in place of low cost and high strength materials has been trigged globally, which has motivated researchers towards biocomposites/green composites. The PLA has been the most promising matrix material for suistanable biocomposites owing to its biodegradability, good availability, eco-friendliness, antibacterial property, and good mechanical and thermal properties. The PLA-based biocomposites are economical, full/partial biodegradable depends upon types of reinforcement, light in weight, and also offer good thermal and mechanical properties. A number of research works have been performed on PLA and its biocomposites to explore their potential for sustainable products. However, no comprehensive review with up-to-date research data on PLA and its biocomposites are reported so far. This fact motivated to summerize the reported studies on PLA and its biocomposites. The aim of present review is to highlight the current and past trends in the research of PLA and its biocomposites. This review article covers current and past efforts reported by researchers on the synthesis and sustainability of PLA, processing, characterization, applications and future scope of its biocomposites. This study observed that PLA-based composites are the most emerging materials that can replace existing non-biodegradable and non-renewable synthetic materials. The PLA-based biocomposites could be considered as the best source of sustainable products. PLA's mechanical and thermal properties can be enhanced by reinforcing the nano and micro sizes of natural fibers and cellulose.

Polymers have proven to be a successful alternative to conventional toxic corrosion inhibitors. Because they have a lot of electron-rich donor sites, they can effectively adsorb on metallic surfaces, offering excellent surface coverage and protection. They have a large number of applications in coating and anti-corrosion solution phases. Currently, corrosion science and engineering strongly encourage the invention and utilization of biodegradable, nonbioaccumulative, and eco-friendly materials because of the increasing demand for green chemistry and sustainable developments. This prompts the widespread use of natural polymers. Unfortunately, they frequently experience physiochemical changes that negatively impact their performance, especially at high temperatures and electrolyte concentrations. The extraction, purification, characterization, and application of natural polymers are typically laborious, drawn-out and not cost-effective approaches. Therefore, biodegradable synthetic polymers (BDSPs) have emerged as ideal substitutes for sustainable corrosion protection. There are numerous studies that cover the various facets of corrosion inhibition, but they rarely discuss BDSPs' overall corrosion inhibition potential. The current report discusses the potential of common BDSPs to inhibit corrosion. The obstacles and potential of using biodegradable synthetic polymers in sustainable corrosion mitigation have also been discussed.

Plastics are the most utilized materials for product packaging in most manufacturing industries, from electronics to food and fashion accessories. However, numerous challenges surround plastics because of their non-biodegradability, which poses a severe threat to the environment. This study has uncovered the possibilities of replacing and discouraging the use of plastics in the packaging of products. A few scholarly articles have successfully proven that biopolymers which are valuable polymers obtained from plant-based and organic materials are better for packaging products. Unlike plastics, biopolymers are biocompatible and biodegradable within a short period, which would help preserve the ecosystem and are healthier for humans. More specifically, biopolymers have found valuable applications in consumer products, medical, electrical, and structural products. Numerous studies on plastic are still ongoing, owing to the increasing demand and quest for removing plastics from human communities, making this area of study very prolific and grey.