Ferrofluids (FFs) or magnetic nanofluids are incredible smart materials consisting of ultrafine magnetic nanoparticles suspended in a liquid carrier medium, which exhibit both fluidity and magnetic controllability. Studies involving the dynamics and physicochemical properties of these magnetic nanofluids are an interdisciplinary area of research attracting researchers from different fields of science and technology. Herein, a comprehensive Review on the different aspects of FF research is presented. First, the synthesis and stabilization of various types of FFs are discussed followed by their physicochemical features such as polydispersity, magnetic behavior, dipolar interactions, formation of chainlike aggregates, and long‐range ordering. The Review also details the rheological and thermal properties, dynamic instabilities, phase behavior, and particle assemblies in FFs to form complex multipolar geometries, photonic nanostructures, labyrinth structures, thin films, and droplets. Many important characterization techniques for probing FF properties are also briefly discussed, and the numerous innovative applications and future prospects of FFs are outlined.

Shape-memory polymer composite (SMPC) blends with thermo-responsive shape memorizing capability have received increasing interest and have been a grooming research area due to their various potential applications. In this work, we report three thermo-responsive SMPCs derived from poly­(ε-caprolactone) (PCL) and the polystyrene-block-polybutadiene-block-polystyrene-tri-block copolymer (SBS) encapsulated with CuO, Fe2O3, and CuFe2O4, namely, SMPC–CuO, SMPC–Fe 2 O 3 , and SMPC–CuFe 2 O 4 , respectively. We have also synthesized the neat shape-memory polymer matrix SMP in the context of the effect of the metal oxide encapsulates on the shape-memory property. Neat SBS rubber and PCL are used as the polymer-elastomer blend matrix to form SMP. The objective of this study is to understand the effect of these three metal oxide nanofillers encapsulated within the SMP matrix and their thermal, mechanical, and shape-memory properties. Morphological, thermal, mechanical, and shape-memory properties of the prepared SMPCs are completely characterized. It is revealed that the addition of nano-metallic-oxide fillers into the polymeric matrix significantly improved the overall properties of SMPCs. The tensile test confirmed that SMPC–CuFe 2 O 4 possesses a high tensile modulus and is found to be very rigid when compared to other SMPCs. The shape fixing property is found in the increasing order as follows: SMPC–CuO > SMPC–Fe 2 O 3 > SMP > SMPC–CuFe 2 O 4 . The better thermal, mechanical, and shape-memory performances were shown by the SMPC–Fe 2 O 3 composite, and thus, it can be considered as the better shape-memory polymer nanocomposite among all others. An optimum storage modulus was attained by SMPC–Fe 2 O 3 among the SMPCs. More interestingly, we have developed a microvalve actuator system using SMPC–Fe 2 O 3 , which could be useful for promising microsystem applications.

Metal-organic frameworks built from [Fe 3 (μ 3-O)(COO) 6 ] clusters and fumaric acid ligand, the so-called MIL-88 A(Fe) is a wellknown environment-friendly promising material for many applications. In this paper, three different morphologies of MIL-88 A(Fe) such as rod, diamond and spindle have been synthesized separately by reacting FeCl 3 * 6H 2 O and fumaric acid in 1 : 1 metal-ligand stoichiometric ratio using two different solvents such as water and DMF via hydrothermal method. The morphology of the products and their particle sizes were obtained using SEM and three distinct morphologies viz., rod, diamond and spindle were clearly distinguished by TEM. All the three samples were characterized by FT-IR, PXRD, UVDRS, PL, XPS and BET, and the effect of the morphologies of MIL-88 A (Fe) on the photocatalytic degradation of Rhodamine B (RhB) was studied under sunlight. The addition of an H 2 O 2 electron acceptor can markedly enhance the photocatalytic Rhodamine B degradation of MIL-88 A(Fe). Among these three, rod-shaped morphology of MIL-88 A(Fe) shows the higher photocatalytic effect for the degradation of Rhodamine B under sunlight due to its lower band gap, high surface area, and lower electronhole recombination rate which enable them the transfer of electrons for the photocatalytic degradation. We found that 98% degradation of RhB in 50 min has taken place by using r-MIL-88 A(Fe) as the catalyst under sunlight.

Stationary energy storage methods such as flow batteries are one of the best options to integrate with smart power grids. Though electrochemical energy storage using flow battery technologies has been successfully demonstrated since the 1970s, the introduction of ionic liquids into the field of energy storage introduces new dimensions in this field. This reliable energy storage technology can provide significantly more flexibility when incorporated with the synergic effects of ionic liquids. This mini-review enumerates the present trends in redox flow battery designs and the use of ionic liquids as electrolytes, membranes, redox couples, etc. explored in these designs. This review specifically intends to provide an overview of the research prospects of ionic liquids for redox flow batteries (RFB).

We have demonstrated the photocatalytic efficiency of the Ag/AgCl@MIL-88A(Fe) composite for the degradation of organic dyes and p-nitrophenol in water.

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The present study introduces the properties of three thermo-responsive shape memory polymer nanocomposites (SMPCs), viz. SMPC-NiO (SMP with nickel oxide), SMPC-Fe 2 O 3 (SMP with iron oxide), and SMPC-Fe 2 NiO 4 (SMP with iron nickel oxide) along with the neat SMP blend. Styrene-Butadiene rubber and poly ε-caprolactone (PCL) polymer are the vital part, which forms the backbone of polymer-elastomer blend matrix. This study helps to understand the effect and influence of these metal oxide nanofillers' integrated blend on their different inbuilt properties. The tensile test and dynamic mechanical analysis studies confirmed that SMPC-Fe 2 NiO 4 holds a large elastic modulus value and very rigid compared to other SMPCs. Thermal decomposition studies using differential scanning calorimetry, thermogravimetric (TG) analysis, and TG-gas chromatography and mass spectrometry results show that the nanocomposites undergoes a two-stage decomposition process. The shape memory test reveals that the time taken for temporary shape recovery is high for SMPC-Fe 2 NiO 4 because of its rigid nature and low for SMPC-Fe 2 O 3 . The results revealed that, from this exploratory study, the integration of metal oxide nanopowder fillers, especially Fe 2 O 3 with neat SMP, showed better properties.

The present work focuses on the evolution in the mechanical properties of an unsaturated polyester resin (UPR) on blending with itaconimide‐end terminated polyethers, namely, polypropylene glycol (I‐PPG), polyethylene glycol (I‐PEG), and polytetra methylene oxide (I‐PTMO). Blends of an unsaturated polyester (UPR, based on propylene glycol, terephthalic, and maleic acids) resin with different loading of itaconimide end‐capped telechelics were investigated for their mechanical and thermal properties. Blending with these additives enhanced the mechanical and thermal properties of the crosslinked UPR. The impact strength and fracture toughness values were improved by more than 100% by small quantities of the additives. The improvement in fracture properties was correlatable primarily to a decrease in overall crosslink density. The distribution of the polyether chains in the cured matrix as dictated by the reactivity ratios of styrene and polyether macromer was found to have a role in deciding the properties. The properties were found to be the best for the blend toughened with I‐PPG with a molecular weight 2000 g/mole at a loading of 2.5 parts per hundred parts. On comparison with the resin blended with a maleimide‐encapped polyether of same molecular weight, the itaconimide end‐capped polyether was found to provide a better toughening of the UPR matrix. This could a priori be explained based on a difference in distribution of the end‐capped polyether as a consequence of the difference in the copolymerization behavior of itaconimide and maleimide functionalized telechelics toward UPR. The itaconimide enters into a random copolymerization with styrene and the probability for formation of the continuous sequences of the itaconic group is about 60%. This will permit polyether segments to come close enough to form micro or even sub‐micron clusters of the polyether which eventually forms the micro crystallites of poly ether that act as a crack stopper. This possibility cannot be envisaged in maleimides which forms invariably an alternating sequence with styrene. The morphological features as reflected in scanning electron microscopic analyses tallied with these observations. This work could help identify the ways for obviating the inherent brittleness of the UPR systems.