Hyper-Crosslinked Polymer Nanocomposites Containing Mesoporous Silica Nanoparticles with Enhanced Adsorption Towards Polar Dyes

Hyper-Crosslinked Porous Organic Nanomaterials: Structure-Oriented Design and Catalytic Applications

Hyper-crosslinked porous organic nanomaterials, especially the hyper-crosslinked polymers (HCPs), are a unique class of materials that combine the benefits of high surface area, porous structure, and good chemical and thermal stability all rolled into one. A wide range of synthetic methods offer an enormous variety of HCPs with different pore structures and morphologies, which has allowed HCPs to be developed for gas adsorption and separations, chemical adsorption and encapsulation, and heterogeneous catalysis. Here, we present a systematic review of recent approaches to pore size modulation and morphological tailoring of HCPs and their applications to catalysis. We mainly compare the effects of pore size modulation and morphological tailoring on catalytic applications, aiming to pave the way for researchers to develop HCPs with an optimal performance for modern applications.

Hybrid Polymer-Silica Nanostructured Materials for Environmental Remediation

Due to the ever-growing global population, it is necessary to develop highly effective processes that minimize the impact of human activities and consumption on the environment. The levels of organic and inorganic contaminants have rapidly increased in recent years, posing a threat to ecosystems. Removing these toxic pollutants from the environment is a challenging task that requires physical, chemical, and biological methods. An effective solution involves the use of novel engineered materials, such as silica-based nanostructured materials, which exhibit a high removal capacity for various pollutants. The starting materials are also thermally and mechanically stable, allowing for easy design and development at the nanoscale through versatile functionalization procedures, enabling their effective use in pollutant capture. However, improvements concerning mechanical properties or applicability for repeated cycles may be required to refine their structural features. This review focuses on hybrid/composite polymer-silica nanostructured materials. The state of the art in nanomaterial synthesis, different techniques of functionalization, and polymer grafting are described. Furthermore, it explores the application of polymer-modified nanostructured materials for the capture of heavy metals, dyes, hydrocarbons and petroleum derivatives, drugs, and other organic compounds. The paper concludes by offering recommendations for future research aimed at advancing the application of polymer-silica nanostructured materials in the efficiency of pollutant uptake.

Lignin-Based Nanoparticles as Both Structural and Active Elements in Self-Assembling and Self-Healing Multifunctional Hydrogels for Chronic Wound Management

Efficient wound healing is feasible when the dressing materials simultaneously target multiple factors causing wound chronicity, such as deleterious proteolytic and oxidative enzymes and bacterial infection. Herein, entirely bio-based multifunctional self-assembled hydrogels for wound healing were developed by simply mixing two biopolymers, thiolated hyaluronic acid (HA-SH) and silk fibroin (SF), with lignin-based nanoparticles (NPs) as both structural and functional elements. Sono-enzymatic lignin modification with natural phenolic compounds results in antibacterial and antioxidant phenolated lignin nanoparticles (PLN) capable of establishing multiple interactions with both polymers. These strong and dynamic polymer-NP interactions endow the hydrogels with self-healing and shear-thinning properties, and pH-responsive NP release is triggered at neutral to alkaline pH (7-9). Despite being a physically crosslinked hydrogel, the material was stable for at least 7 days, and its mechanical and functional properties can be tuned depending on the polymer and NP concentration. Furthermore, human skin cells in contact with the nanocomposite hydrogels for 7 days showed more than 93% viability, while the viability of clinically relevant Staphylococcus aureus and Pseudomonas aeruginosa was reduced by 99.7 and 99.0%, respectively. The hydrogels inhibited up to 52% of the activity of myeloperoxidase and matrix metalloproteinases, responsible for wound chronicity, and showed a strong antioxidant effect, which are crucial features promoting wound healing.

Amino-Functionalized Titanate Nanotubes: pH and Kinetic Study of a Promising Adsorbent for Acid Dye in Aqueous Solution

This work reports the functionalization of sodium titanate nanotubes with amine groups obtained from the reaction of titanate nanotubes with [3-(2-Aminoethylamino)propyl]trimethoxysilane, NaTiNT-2NH, and 3-[2-(2-Aminoethylamino)ethylamino]propyltrimethoxysilane, NaTiNT-3NH. It was verified that the crystalline and morphological structures of NaTiNT were preserved after the functionalization, spectroscopies showed that aminosilane interacted covalently with the surface of NaTiNT, and the incorporation of the aminosilane groups on the surface of NaTiNT can be confirmed. The adsorbent matrices NaTiNT-2NH and NaTiNT-3NH were used to remove the anionic dye from remazol blue R (RB) in aqueous medium, and the highest adsorption capacity was around 365.84 mg g-1 (NaTiNT-2NH) and 440.70 mg g-1 (NaTiNT-3NH) in the range of pH 5.0 to 10.0 and the equilibrium time was reached in 210 min (NaTiNT-2NH) and 270 min (NaTiNT-3NH). Furthermore, the Elovich model, which reports the adsorption in heterogeneous sites and with different activation energies in the chemisorption process, was the most appropriate to describe the adsorption kinetics. Thus, these adsorbent matrices can be used as an alternative potential for dye removal RB in aqueous solution.

Recent advances in porous organic frameworks for sample pretreatment of pesticide and veterinary drug residues: a review

Rapid and accurate detection of pesticide and veterinary drug residues is a continuing challenge because of the complex matrix effects. Thus, appropriate sample pretreatment is a crucial step for the effective extraction of the analytes and removal of the interferences. Recently, the development of nanomaterial adsorbents has greatly promoted the innovation of food sample pretreatment approaches. Porous organic frameworks (POFs), including polymers of intrinsic microporosity, covalent organic frameworks, hyper crosslinked polymers, conjugated microporous polymers, and porous aromatic frameworks, have been widely utilized due to their tailorable skeletons and pores as well as fascinating features. This review summarizes the recent advances for POFs to be utilized in adsorption and sample preparation of pesticide and veterinary drug residues. In addition, future prospects and challenges are discussed, hoping to offer a reference for further study on POFs in sample pretreatment.

Innovative Silver-Based Capping System for Mesoporous Silica Nanocarriers Able to Exploit a Twofold Anticorrosive Mechanism in Composite Polymer Coatings: Tailoring Benzotriazole Release and Capturing Chloride Ions

In this work, engineered stimuli-responsive mesoporous silica nanoparticles (MSNs) were developed and exploited in polymer coatings as multifunctional carriers of a typical corrosion inhibitor, benzotriazole (BTA). In detail, a new capping system based on a BTA-silver coordination complex, able to dissolve in acid and alkaline conditions and to simultaneously tailor the BTA release and the capture of chloride ions, was properly designed and realized. Acrylic coatings embedding the engineered MSNs were deposited onto iron rebar samples and tested for their protective capability in acid and alkaline environments. Results highlighted the high potential of the proposed system for the protection of metals, due to the synergistic effect of the mesoporous structure and the capping system, which guaranteed both the sequestration of chloride ions and the on-demand release of the effective amount of anticorrosive agents able to ensure the enhanced protection of the substrate.

Mesoporous silica nanoparticles as carriers of active agents for smart anticorrosive organic coatings: a critical review

Mesoporous silica nanoparticles (MSN) have attracted increasing interest for their applicability as smart nanocarriers of corrosion inhibitors, due to their porous structure, resistance to main corrosive environments and good compatibility with polymer coatings. In this review, the main synthetic routes to obtain MSN with tailored textural properties, the design of different loading and stimuli-induced release strategies, the development of advanced organic nanocomposite coatings with MSN and the validation of their anticorrosive performances are reviewed and compared. Through a critical analysis of the literature, the most promising research trends and perspectives to exploit the highly interesting properties of MSN in advanced organic coatings are proposed.