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The near‐surface mounted (NSM) technique over the years has become the most popular retrofitting technique for obtaining enhanced strength and durability in reinforced concrete structural elements. It is mostly preferred for its easy application of composites in grooves cut on specimen concrete cover. The specimen surface is prepared with slits where polymer composite laminates are placed along with adhesives as filler to attain good bonding between laminates and the surface. The paper reviews the NSM carbon fiber reinforced polymer technique and its ascendancies over externally bonded composites retrofitting approach. Members strengthened with the NSM technique show enhanced shear strength, flexural capacity, and fatigue resistance. Motivated by the urge of gaining knowledge on various advantages of this emerging method, the paper reviews the load‐carrying capacity, failure modes, durability, and bonding behavior along with the enhancement ascertained in shear, flexure, and fatigue resistance by the NSM technique. In addition to offering guidance on the experimental and computational investigations on the overall behavior of the technique, the present review also intends to encourage further development in the near‐surface mounted carbon fiber polymer strengthening system of retrofit. [ABSTRACT FROM AUTHOR]

Extensive development in electronics and allied sectors has led to unseen pollution termed electromagnetic interference (EMI). Motivated by its after‐effects, the fabrication of efficient EMI shielding has become a major area of research. This review presents a detailed analysis of very recent trends in various hybrid materials based on polymers, cement, concrete, paints, and so on with diverse filler inclusions for electromagnetic shielding applications. This paper also focuses on the origin and effects of electromagnetic (EM) radiation, the shielding mechanism, and the suitability of the hybrids, various fabrication techniques, characterization; and so on. Fiber‐reinforced polymer composites, metal films, microfilms, inks, paints, multiple laminated composites, foams, aerogel‐based polymer composites, textiles, and so on are discussed. Newly developed materials like MXene, borophene, semiconducting filler‐based hybrid materials are also covered. Finally, an attempt is made, to sum up, the major challenges faced in the design and development of polymer materials for EMI shielding applications. [ABSTRACT FROM AUTHOR]

Composites are used in a variety of applications due to their excellent properties. However, structural polymers are sensitive and susceptible to thermal and mechanical damage in form of micro-cracks, which are onset to grow deep within the structure where detection and repair are practically impossible. To overcome these problems, broad range of self-healing structures have emerged. This technology has led to an increase in the material's lifetime and safety while reducing the repair and replacement costs. Capsule-based healing systems are a well-known technology that has many uses in smart protective coatings, dental composites, concrete components, and generally for polymer and fiber-reinforced composites. This article summarizes the research work on the capsule-based self-healing system over the last two decades. In this regard, after a brief introduction, various types of microencapsulation-based methods used in healing systems are classified. After explaining the manufacturing process of capsules, parameters affecting the microencapsulation quality particularly, agitation rate, core to shell weight ratio, monomer viscosity, solvent property, reaction time, temperature, pH, and U/F ratio are explained in detail. Finally, the most common healing efficiency evaluation methods are described. This review provides the reader with an overview of achievements to date, and insight into future development for industrial and engineering applications. 2MZ-Azine 2,4-diamino-6[-2-methyl-imidazolyl(1)]-ethyl-cis-triazine 2PhI 2-phenyl Imidazole BGE N-butyl Glycidyl Ether CAI Compression After Impact CB Carbon Black CC Compliance Calibration CNS Calcium hydroxide (Ca(OH)) Nano-spherulites CNTs Carbon Nanotubes DCB Double Cantilever Beam DCM Dichloromethane DCPD Dicyclopentadiene DGEBA Diglycidyl Ether of Bisphenol A DTHP Diglycidyl Tetrahydro-o-Phthalate EDA Ethylenediamine ENB Ethylidene Norbornene EPA Ethyl Phenyl Acetate FCG Fatigue Crack Growing FRP Fiber-Reinforced Polymer GHS Globally Harmonized System of the Classification and Labeling of Chemicals GO Graphene Oxide HGFs Hollow Glass Fibers IPDI Isophorone Diisocyanate MBT Modified Beam Theory MCC Modified Compliance Calibration MF Melamine-Formaldehyde MWCNT Multi-Walled Carbon Nanotube NaCMC Carboxymethyl Cellulose O/W Oil-in-Water PA Phenyl Acetate PAA Phthalic Anhydride PAANa Sodium Polyacrylate PCL Polycaprolactone PCP Polycyclopentadiene PDA Polydopamine PDMS Poly (Dimethyl-Siloxane) PEA Polyetheramine PhCl Chlorobenzene PMCs Polymer Matrix Composites PMMA Poly (Methyl-Methacrylate) PMUF Poly (Melamine-Urea-Formaldehyde) PU Polyurethane PVA Polyvinyl Alcohol ROMP Ring-Opening Metathesis Polymerization SEM Scanning Electron Microscope SENB Single-Edge Notched Bending SIFs Stress Intensity Factors SWCNT Single-Wall Carbon Nanotube TDCB Trapped Double Cantilever Beam TGA Thermogravimetric Analysis UF Urea-Formaldehyde UFM UF Microcapsules W/O Water-in-Oil W/O/W Water-in-Oil-in-Water η Healing efficiency K IC Critical stress intensity factor (Mode I) a Crack length δ Crack opening displacement w Specimen length b Specimen width d Specimen thickness P C Critical fracture load E Young's modulus C Compliance G IC Critical energy release rate (Mode-I) U Internal work (Strain energy) N Number of Fatigue cycles [ABSTRACT FROM AUTHOR]

In the past two decades (2001–2020), researchers have been attracted toward hybrid composite materials reinforced with synthetic and natural fibers. Bio‐degradability and harmlessness to the environment are the major attributes of natural fibers, such qualities support these fibers to reinforce into composites. At the same time, higher moisture absorption and poor compatibility characteristics of natural fibers have forced to hybridize with other synthetic/natural fibers. Several researchers have already done the hybridization of natural fibers with synthetic/natural fibers to overcome the limitations of natural fibers. Due to this reason, we perform a literature review on the influence of hybridization on the properties of composites reinforced with synthetic and natural fibers. This review is made on resulting properties of hybrid composites such as mechanical, thermal, water absorption, tribological behavior, morphological characteristics, and other properties from the year 2001 to 2020. [ABSTRACT FROM AUTHOR]

Reinforcing polymers with particles and fibers has been a common strategy for decades, in order to make them suitable for high‐demanding industrial applications. As composites often undergo dynamic loads, it is important to understand their behavior under such conditions. This review first classifies the types of polymer composites and then explains their failure behavior under tension and compression loading, followed by an overview of some of the experimental procedures used to characterize the polymer composites' dynamic mechanical performance. Afterward, the most significant findings in terms of the high‐strain‐rate compressive and tensile strength and modulus of polymer composites are thoroughly discussed. The results, available in the literature, on the mechanical properties of polymer composites under quasi‐static conditions are also presented and compared with the high‐strain‐rate data. The differences are explained by discussing the changes in the structural configurations of polymer matrices under quasi‐static and dynamic loads. Lastly, conclusions and future perspectives are given, with the intent of highlighting the most promising polymer composites that can be used for a wide variety of applications. [ABSTRACT FROM AUTHOR]

One of the most promising pharmaceutical research areas is developing advanced delivery systems for controlled and sustained drug release. The drug delivery system (DDS) can be designed to strengthen the pharmacological and therapeutic characteristics of different medicines. Natural polymers have resolved numerous commencing hurdles, which hindered the clinical implementation of traditional DDS. The naturally derived polymers furnish various advantages such as biodegradability, biocompatibility, inexpensiveness, easy availability, and biologically identifiable moieties, which endorse cellular activity in contrast to synthetic polymers. Among them, chitosan has recently been in the spotlight for devising safe and efficient DDSs due to its superior properties such as minimal toxicity, bio-adhesion, stability, biodegradability, and biocompatibility. The primary amino group in chitosan shows exceptional qualities such as the rate of drug release, anti-microbial properties, the ability to cross-link with various polymers, and macrophage activation. This review intends to provide a glimpse into different practical utilization of chitosan as a drug carrier. The first segment of the review will give cognizance into the source of extraction and chitosan's remarkable properties. Further, we have endeavored to provide recent literature pertaining to chitosan applications in various drug delivery systems via different administration routes along with current patented chitosan formulations. Unlabelled Image [ABSTRACT FROM AUTHOR]