Ultra-stable metal-organic framework-derived carbon nanocontainers with defect-induced pore enlargement for anti-corrosive epoxy coatings.

Zeolitic imidazolate frameworks-8 (ZIF-8) have recently gained attention as nanocontainers for encapsulating corrosion inhibitors. However, two main challenges remain unsolved, casting doubt on their suitability as nanocontainers. The first challenge is their instability in acidic and basic environments, leading to structural decomposition and the second challenge is their mass diffusion limitation caused by micropore dominance and a small aperture size of 0.

From Wet to Protective: Film Formation in Waterborne Coatings.

The importance of anticorrosive coatings cannot be overstated, as they play a vital role in safeguarding assets and infrastructure across various industries. Within this context, the emergence of waterborne (WB) coatings stands out for their paramount significance, offering a sustainable alternative to traditional solvent-based (SB) coatings and addressing pressing environmental concerns. Despite their eco-friendliness, the complexity of their film formation mechanism and the lack of understanding present challenges in enhancing the performance of waterborne coatings for corrosion protection.

Advanced materials for smart protective coatings: Unleashing the potential of metal/covalent organic frameworks, 2D nanomaterials and carbonaceous structures.

The detrimental impact of corrosion on metallic materials remains a pressing concern across industries. Recently, intelligent anti-corrosive coatings for safeguarding metal infrastructures have garnered significant interest. These coatings are equipped with micro/nano carriers that store corrosion inhibitors and release them when triggered by external stimuli.

Synthesis of Mesoporous Silica Particles as Inhibitor Containers for Anticorrosive Applications.

Herein, we introduce an innovative experimental assembly based on a high-speed disperser and a water recirculator connected to a double-wall stainless steel container as a new and effective pathway for an eco-friendly and controlled synthesis of mesoporous silica particles (MSPs). With the setup, we demonstrated a one-pot encapsulation of the particles with an inhibitor benzotriazole (BTA) to produce a smart nano/microcontainer for potential use in anticorrosive coatings. One advantage of the experimental setup is the high volume of reactant solution that can be used, yet with good control of solution temperature and stirring conditions, which increases the yield and saves laboratory time.

Encapsulated Corrosion Inhibitive Pigment for Smart Epoxy Coating Development: An Investigation of Leaching Behavior of Inhibitive Ions.

A comparative study between the leaching behavior of inhibitive ions from conventionally pigmented and smart (with encapsulated pigments) epoxy coatings has been conducted. Leaching of calcium phosphate as an inhibitive pigment from epoxy coatings was tested in 3.5 wt % NaCl solution.

Assessment of Anticorrosion Performance of Zinc-Rich Epoxy Coatings Added with Zinc Fibers for Corrosion Protection of Steel.

The effect of adding 0.5 wt % zinc fibers on the anticorrosion performance of zinc-rich epoxy (ZRE) coatings with 85, 75, and 65 wt % of zinc dust was investigated. The salt spray testing, scanning electron microscopy, open circuit potential, and electrochemical impedance spectroscopy measurements were used to characterize the corrosion protection performance of coatings.

Characterization and Release Mechanisms of Aerogel-Encapsulated Biocide Crystals for Low-Loading and High-Utilization Antifouling Coatings.

Silica aerogel-encapsulated biocide crystals can potentially enhance the protection efficiency of antifouling coatings, thereby lowering the impact on nontarget aquatic life. In the present study, copper pyrithione (CuPT) crystals are encapsulated by silica aerogel to obtain loadings of 50-80 wt % CuPT. For optimal design of the heterogeneous particles and mapping of the underlying biocide release mechanisms, the aerogel-encapsulated biocide crystals are characterized by scanning (transmission) electron microscopy, energy-dispersive X-ray spectroscopy, thermal gravimetric analysis, mercury intrusion porosity, Brunauer-Emmett-Teller analysis, and light scattering.

A Tunable Hyperspectral Imager for Detection and Quantification of Marine Biofouling on Coated Surfaces.

Fouling control coatings (FCCs) are used to prevent the accumulation of marine biofouling on, e.g., ship hulls, which causes increased fuel consumption and the global spread of non-indigenous species.

A review of blasting waste generation and management in the ship repair industry.

Solid blasting waste generated from coating removal during ship repair and maintenance poses environmental challenges. This paper presents a review of the generation, characterization, and treatment of blasting waste in the ship repair industry. The quantities, properties, and environmental impacts of the generated blasting waste are summarized and analyzed, and the results indicate that blasting waste has a high generation rate and/or high toxicity.

Reliable Condensation Curing Silicone Elastomers with Tailorable Properties.

The long-term stability of condensation curing silicone elastomers can be affected by many factors such as curing environment, cross-linker type and concentration, and catalyst concentration. Mechanically unstable silicone elastomers may lead to undesirable application failure or reduced lifetime. This study investigates the stability of different condensation curing silicone elastomer compositions.

Reactor design for minimizing product inhibition during enzymatic lignocellulose hydrolysis: II. Quantification of inhibition and suitability of membrane reactors.

Product inhibition of cellulolytic enzymes affects the efficiency of the biocatalytic conversion of lignocellulosic biomass to ethanol and other valuable products. New strategies that focus on reactor designs encompassing product removal, notably glucose removal, during enzymatic cellulose conversion are required for alleviation of glucose product inhibition. Supported by numerous calculations this review assesses the quantitative aspects of glucose product inhibition on enzyme-catalyzed cellulose degradation rates.

Reactor design for minimizing product inhibition during enzymatic lignocellulose hydrolysis: I. Significance and mechanism of cellobiose and glucose inhibition on cellulolytic enzymes.

Achievement of efficient enzymatic degradation of cellulose to glucose is one of the main prerequisites and one of the main challenges in the biological conversion of lignocellulosic biomass to liquid fuels and other valuable products. The specific inhibitory interferences by cellobiose and glucose on enzyme-catalyzed cellulose hydrolysis reactions impose significant limitations on the efficiency of lignocellulose conversion - especially at high-biomass dry matter conditions. To provide the base for selecting the optimal reactor conditions, this paper reviews the reaction kinetics, mechanisms, and significance of this product inhibition, notably the cellobiose and glucose inhibition, on enzymatic cellulose hydrolysis.

A passive apparatus for controlled-flux delivery of biocides: hydrogen peroxide as an example.

A new test method has been developed to estimate the required release rate of hydrogen peroxide (H2O2) to prevent marine biofouling. The technique exploits a well-defined concentration gradient of biocide across a cellulose acetate membrane. A controlled flux of H2O2, an environmentally friendly biocide, was obtained.

Effect and modeling of glucose inhibition and in situ glucose removal during enzymatic hydrolysis of pretreated wheat straw.

The enzymatic hydrolysis of lignocellulosic biomass is known to be product-inhibited by glucose. In this study, the effects on cellulolytic glucose yields of glucose inhibition and in situ glucose removal were examined and modeled during extended treatment of heat-pretreated wheat straw with the cellulolytic enzyme system, Celluclast 1.5 L, from Trichoderma reesei, supplemented with a beta-glucosidase, Novozym 188, from Aspergillus niger.

Effects of substrate loading on enzymatic hydrolysis and viscosity of pretreated barley straw.

In this study, the applicability of a "fed-batch" strategy, that is, sequential loading of substrate or substrate plus enzymes during enzymatic hydrolysis was evaluated for hydrolysis of steam-pretreated barley straw. The specific aims were to achieve hydrolysis of high substrate levels, low viscosity during hydrolysis, and high glucose concentrations. An enzyme system comprising Celluclast and Novozyme 188, a commercial cellulase product derived from Trichoderma reesei and a beta-glucosidase derived from Aspergillus niger, respectively, was used for the enzymatic hydrolysis.

Presence and effects of marine microbial biofilms on biocide-based antifouling paints.

Marine microorganisms are capable of successfully colonizing toxic surfaces through the formation of biofilm structures. In this article, most of the literature reporting the presence of marine biofilms on chemically-active antifouling paints is briefly reviewed. Of special concern is the influence of the dense extracellular polymeric substances (EPS) matrix on the release rate of the compounds involved in antifouling paint performance (i.

Estimation of polishing and leaching behaviour of antifouling paints using mathematical modelling: a literature review.

The development of chemically active antifouling paints has traditionally been based on an empirical approach. Optimisation and evaluation of novel and existing products are frequently conducted by means of, for example, systematic paint rotary tests in the laboratory or at sea sites. In this review, the usefulness of combining rotary experiments with the development of detailed mathematical models of paint behaviour will be discussed with reference to the relevant literature.

Controlled drug delivery from swellable hydroxypropylmethylcellulose matrices: model-based analysis of observed radial front movements.

This work is related to the on-going development of mathematical models describing transient drug delivery from hydroxypropylmethylcellulose (HPMC) matrices. Recently, experimental data providing a detailed mapping of radial swelling, diffusion, and erosion front movements in a high-viscosity HPMC matrix were published [J. Controlled Release 70 (2001) 383].