Intelligent micro- and nanocapsules

Behaviour of FITC-Labeled Polyallylamine in Polyelectrolyte Microcapsules

There are many studies devoted to the application of polyelectrolyte microcapsules (PMC) in various fields; however, there are significantly fewer studies devoted to the study of the polyelectrolyte microcapsules themselves. The study examined the mutual arrangement of the polyelectrolytes in 13-layered PMC capsules composed of (PAH/PSS)6PAH. The research showed that different layers of the polyelectrolyte microcapsules dissociate equally, as in the case of 13-layered PMC capsules composed of (PAH/PSS)6PAH with a well-defined shell, and in the case of 7-layered PMC capsules composed of (PAH/PSS)3PAH, where the shell is absent. The study showed that polyallylamine layers labeled with FITC migrate to the periphery of the microcapsule regardless of the number of layers. This is due to an increase in osmotic pressure caused by the rapid flow of ions from the interior of the microcapsule into the surrounding solution. In addition, FITC-polyallylamine has a lower charge density and less interaction with polystyrene sulfonate in the structure of the microcapsule. Meanwhile, the hydrophilicity of FITC-polyallylamine does not change or decreases slightly. The results suggest that this effect promotes the migration of labeled polyallylamine to a more hydrophilic region of the microcapsule, towards its periphery.

Fortification by design: A rational approach to designing vitamin D delivery systems for foods and beverages

Over the past few decades, vitamin D deficiency has been recognized as a serious global public health challenge. The World Health Organization has recommended fortification of foods with vitamin D, but this is often challenging because of its low water solubility, poor chemical stability, and low bioavailability. Studies have shown that these challenges can be overcome by encapsulating vitamin D within well-designed delivery systems containing nanoscale or microscale particles. The characteristics of these particles, such as their composition, size, structure, interfacial properties, and charge, can be controlled to attain desired functionality for specific applications. Recently, there has been great interest in the design, production, and application of vitamin-D loaded delivery systems. Many of the delivery systems reported in the literature are unsuitable for widespread application due to the complexity and high costs of the processing operations required to fabricate them, or because they are incompatible with food matrices. In this article, the concept of "fortification by design" is introduced, which involves a systematic approach to the design, production, and testing of colloidal delivery systems for the encapsulation and fortification of oil-soluble vitamins, using vitamin D as a model. Initially, the challenges associated with the incorporation of vitamin D into foods and beverages are reviewed. The fortification by design concept is then described, which involves several steps: (i) selection of appropriate vitamin D form; (ii) selection of appropriate food matrix; (iii) identification of appropriate delivery system; (iv) identification of appropriate production method; (vii) establishment of appropriate testing procedures; and (viii) system optimization.

Recent progress on quality improvement and detection technologies of special foods used for activities in space and aviation: a review

This paper focuses on the development and evolution, quality improvement and research progress in the rapidly emerging area of new detection technologies of special foods for use in space and to some extent aviation. The quality improvement aspects covered in this review ranged from the special food processing technology, sterilization treatment and product packaging to new detection technologies for quality assurance based on DNA microarray technology, sensor, imaging technology, carbon nanotubes and novel probe technology.

Merging Porphyrins with Gold Nanorods: Self Assembly Construct to High Fluorescent Polyelectrolyte Microcapsules

Dual probe porphyrin-gold nanorod polyelectrolyte microcapsules were developed to explore the enhancing effects of a plasmonic interface of self-assembled gold nanoparticles in the fluorescence emission from porphyrins loaded into the capsules’ core. An analysis of fluorescence lifetime imaging microscopy (FLIM) data reports a notable 10⁵–10⁶-fold increase in the maximum detected photon rates from diffraction-limited spots and an overall six-fold increase in fluorescence as averaged over the whole microcapsule area. Large emission enhancements were correlated with decreases in fluorescence lifetimes. The microcapsule’s design proved effective in achieving high fluorescent hybrids and may shed light on new possibilities for advanced materials imaging applications.

New sight at the organization of layers of multilayer polyelectrolyte microcapsules

In this work, the mutual arrangement of polyelectrolytes of multilayer polyelectrolyte microcapsules (with layers-[PAH/PSS]3PAH) by determination of the dissociation level of polyallylamine (PAH) from the surface of a polyelectrolyte microcapsules (PMC) of various types was studied: PMC with a dissolved CaCO3 core after preparation, PMC with an undissolved CaCO3 core and PMC with an encapsulated protein. It was concluded that the polyelectrolyte layers are mixed in the entire shell of the capsules with a dissolved CaCO3 core. In the case of the PMC with an undissolved CaCO3 core, such mixing of polyelectrolyte layers does not occur. That fact allows us to conclude that the mixing of polyelectrolytes layers mixing at the stage of dissolution of CaCO3 core. The PMC with encapsulated protein has partial mixing of polyelectrolytes layers. That phenomenon may be due to the fact that seven-layered protein-containing microcapsules already have a dense and well-formed shell. The obtained data correlate with the data on the study of the surface charge of microcapsules.

Synthesis and structure of temperature-sensitive nanocapsules

The transport and systematic release of functional agents at specific areas are key challenges in various application fields. These make the development of micro- and nanocapsules, which allow for uptake, storage, and triggered release, of high interest. Hollow thermoresponsive microgels, cross-linked polymer networks with a solvent-filled cavity in their center, are promising candidates as triggerable nanocapsules, as they can adapt their size and shape to the environment. Their shell permeability can be controlled by temperature, while the cavity can serve as a storage place for guest species. Here, we present the synthesis and structural characterization of temperature-responsive microgels, which are deswollen at room temperature and swell upon moderate cooling, to facilitate potential encapsulation experiments. We present microgels made from poly(N-isopropylacrylamide-co-diacetone acrylamide), p(NIPAM-co-DAAM), possessing a volume phase transition temperature below room temperature. Their colloidal stability in the deswollen state can be enhanced by adding a swollen polymer shell made of poly(N-isopropylacrylamide), pNIPAM, as periphery. The synthesis of hollow double-shell microgels comprising a cavity surrounded by an inner p(NIPAM-co-DAAM) shell and an outer pNIPAM shell is established. The inner network enables the control of the shell permeability: the network is deswollen at room temperature and swells upon moderate cooling. The outer network guarantees for steric stability at room temperature. Light scattering techniques are employed for the characterization of the microgels. Form factor analysis reveals that the cavity of the nanocapsules persists at all swelling states, making it an ideal site for the storage of guest species.

Bio-Based Phase Change Materials Incorporated in Lignocellulose Matrix for Energy Storage in Buildings—A Review

Due to growing consciousness regarding the environmental impact of fossil-based and non-sustainable materials in construction and building applications, there have been an increasing interest in bio-based and degradable materials in this industry. Due to their excellent chemical and thermo-physical properties for thermal energy storage, bio-based phase change materials (BPCMs) have started to attract attention worldwide for low to medium temperature applications. The ready availability, renewability, and low carbon footprint of BPCMs make them suitable for a large spectrum of applications. Up to now, most of the BPCMs have been incorporated into inorganic matrices with only a few attempts to set the BPCMs into bio-matrices. The current paper is the first comprehensive review on BPCMs incorporation in wood and wood-based materials, as renewable and sustainable materials in buildings, to enhance the thermal mass in the environmentally-friendly buildings. In the paper, the aspects of choosing BPCMs, bio-based matrices, phase change mechanisms and their combination, interpretation of life cycle analyses, and the eventual challenges of using these materials are presented and discussed.

Effect of Pollyallylamine on Alcoholdehydrogenase Structure and Activity

In this article, the effect of polyallylamine (PAA) on the structure and catalytic characteristics of alcohol dehydrogenase (ADH) was studied. For this research, we used methods of stationary kinetics and fluorescence spectroscopy. It has been shown that PAA non-competitively inhibits ADH activity while preserving its quaternary structure. It was established that 0.1 M ammonium sulfate removes the inhibitory effect of PAA on ADH, which is explained by the binding of sulfate anion (NH₄)₂SO₄ with polyallylamine amino groups. As a result, the rigidity of the polymer chain increases and the ability to bind to the active loop of the enzyme increases. It is also shown that sodium chloride removes the inhibitory effect of PAA on ADH due to an electrostatic screening of the enzyme from polyelectrolyte. The method of encapsulating ADH in polyelectrolyte microcapsules was adapted to the structure and properties of the enzyme molecule. It was found that the best for ADH is its encapsulation by adsorption into microcapsules already formed on CaCO₃ particles. It was shown that the affinity constant of encapsulated alcohol dehydrogenase to the substrate is 1.7 times lower than that of the native enzyme. When studying the affinity constant of ADH in a complex with PAA to ethanol, the effect of noncompetitive inhibition of the enzyme by polyelectrolyte was observed.

Destruction of Polyelectrolyte Microcapsules Formed on CaCO3 Microparticles and the Release of a Protein Included by the Adsorption Method

The degradation of polyelectrolyte microcapsules formed on protein-free CaCO₃ particles consisting of polyallylamine (PAH) and polystyrene sulfonate (PSS) and the resulting yield of protein in the presence of various salts of different concentrations, as well as at two pH values, was studied by fluorescence spectroscopy; the protein was incorporated into prepared microcapsules by adsorption. It was found that a high concentration of sodium chloride (2 M) leads to considerable dissociation of PAH, which is apparently due to the loosening of polyelectrolytes under the action of ionic strength. At the same time, 0.2 M sodium chloride and ammonium sulfate of the same ionic strength (0.1 M) exert less influence on the amount of dissociated polymer. In the case of ammonium sulfate (0.1 M), the effect is due to the competitive binding of sulfate anions to the amino groups of the polyelectrolyte. However, unlike microcapsules formed on CaCO₃ particles containing protein, the dissociation of polyelectrolyte from microcapsules formed on protein-free particles increased with increasing temperature. Apparently, a similar effect is associated with the absence of a distinct shell, which was observed on microcapsules formed on protein-containing CaCO₃ particles. The high level of the presence of Fluorescein isothiocyanate (FITC)-labeled Bovine Serum Albumin (BSA) in the supernatant is explained by the large amount of electrostatically bound protein and the absence of a shell that prevents the release of the protein from the microcapsules. In 2M NaCl, during the observation period, the amount of the released protein did not exceed 70% of the total protein content in the capsules, in control samples, this value does not exceed 8%, which indicates the predominantly electrostatic nature of protein retention in capsules formed on protein-free CaCO₃ particles. The increase in protein yield and peeling of PAH with increasing pH is explained by the proximity of pH 7 to the point of charge exchange of the amino group of polyelectrolyte, as a result of the dissociation of the microcapsule.

Deciphering and Controlling Structural and Functional Parameters of the Shells in Vesicle-Templated Polymer Nanocapsules

Vesicle-templated nanocapsules are prepared by polymerization of hydrophobic acrylic monomers and cross-linkers in the hydrophobic interior of self-assembled bilayers. Understanding the mechanism of capsule formation and the influence of synthetic parameters on the structural features and functional performance of nanocapsules is critical for the rational design of functional nanodevices, an emerging trend of application of the nanocapsule platform. This study investigated the relationship between basic parameters of the formulation and synthesis of nanocapsules and structural and functional characteristics of the resulting structures. Variations in the monomer/surfactant ratio, temperature of polymerization, and the molar fraction of the free-radical initiators were investigated with a multipronged approach, including shell thickness measurements using small-angle neutron scattering, evaluation of the structural integrity of nanocapsules with scanning electron microscopy, and determination of the retention of entrapped molecules using absorbance and fluorescence spectroscopy. Surprisingly, the thickness of the shells did not correlate with the monomer/surfactant ratio, supporting the hypothesis of substantial stabilization of the surfactant bilayer with loaded monomers. Decreasing the temperature of polymerization had no effect on the spherical structure of nanocapsules but resulted in progressively lower retention of entrapped molecules, suggesting that a spherical skeleton of nanocapsule forms rapidly, followed by filling the gaps to create the structure without pinholes. Lower content of initiators resulted in slower reactions, outlining the baseline conditions for practical synthetic protocols. Taken together, these findings provide insights into the formation of nanocapsules and offer methods for controlling the properties of nanocapsules in viable synthetic methods.

Multilayer Capsules Inside Biological Systems: State-of-the-Art and Open Challenges

There are many reports about the interaction of multilayer capsules with biological systems in the literature. A majority of them are devoted to the in vitro study with two-dimensional cell cultures. Multilayer capsule fabrication had been under intensive investigation from 1990s and 2000s by Prof. Helmuth Möhwald, and many of his followers further developed their own research directions, focusing on capsule implementation in various fields of biology and medicine. The aim of this future article is to consistently consider the most recent advances in cell-capsule interactions for different biomedical applications, including functionalization of clinically relevant cells, nonviral gene delivery, magnetization of cells to control their movement, and in vivo drug delivery. Finally, the description and discussion of the new trends and perspectives for improved functionalities of capsules in design and functionalization of cell-assisted drug vehicles are the major topics of this work.

Layer by layer supported laccase on lignin nanoparticles catalyzes the selective oxidation of alcohols to aldehydes

Lignin nanoparticles support laccase from Trametes versicolor in the selective oxidation of alcohols to aldehydes, in the presence of redox mediators.

Nanoencapsulation of phase change materials for advanced thermal energy storage systems

Phase change materials (PCMs) allow the storage of large amounts of latent heat during phase transition. They have the potential to both increase the efficiency of renewable energies such as solar power through storage of excess energy, which can be used at times of peak demand; and to reduce overall energy demand through passive thermal regulation. 198.3 million tons of oil equivalent were used in the EU in 2013 for heating. However, bulk PCMs are not suitable for use without prior encapsulation. Encapsulation in a shell material provides benefits such as protection of the PCM from the external environment and increased specific surface area to improve heat transfer. This review highlights techniques for the encapsulation of both organic and inorganic PCMs, paying particular attention to nanoencapsulation (capsules with sizes <1 μm). We also provide insight on future research, which should focus on (i) the development of multifunctional shell materials to improve lifespan and thermal properties and (ii) advanced mass manufacturing techniques for the economically viable production of PCM capsules, making it possible to utilize waste heat in intelligent passive thermal regulation systems, employing controlled, "on demand" energy release/uptake.

Preparation and application of flavor and fragrance capsules

The preparation methods and applications of flavor and fragrance capsules based on polymeric, inorganic and polymeric–inorganic wall materials are summarized.

Influence of fluorobenzene mass transfer on the qualities of poly-α-methylstyrene shells

Polymer shells prepared by the microencapsulation technique with perfect sphericity and defect-free surface finish are demanded in inertial confinement fusion (ICF) experiments. The sphericity and surface finish are some of the hardest specifications to fulfill. Driven by the need to improve qualities of the polymer shells to meet the critical specifications, the effects of fluorobenzene (FB) mass transfer rate on sphericity and surface finish were investigated and the mechanisms of the effects of FB mass transfer on sphericity and surface finish of poly-α-methylstyrene (PAMS) were also discussed. The sphericity and surface finish of the PAMS shells are greatly improved by decreasing the FB mass transfer rate. The calculative frequency of the final shells with an out-of-round (δ_OOR) of less than 2 μm increases from 30% to 80%, while the power spectra density (PSD) plot gets closer to the specification of the national ignition facility (NIF). The tracking experiments show that the curing process is extended and the percolation transition is also postponed by decreasing the FB mass transfer rate. Therefore, the interfacial tension can work sufficiently, helping make double droplets become spherical, since the double droplets’ stay in the liquid state is effectively extended. Moreover, the Marangoni instabilities at the O–W2 boundary are also restrained by controlling the mass transfer, due to the diffusivity of FB being slowed down. Both the results and methods presented in this work provide a more in-depth understanding of the curing process and the mass transfer, to the benefit of fabricating polymer shells with high sphericity and defect-free surface finish used in ICF experiments.

Polymer shells prepared by the microencapsulation technique with perfect sphericity and defect-free surface finish are demanded in inertial confinement fusion (ICF) experiments.

Strong Microcapsules with Permeable Porous Shells Made through Phase Separation in Double Emulsions

Microcapsules for controlled chemical release and uptake are important in many industrial applications but are often difficult to produce with the desired combination of high mechanical strength and high shell permeability. Using water-oil-water double emulsions made in microfluidic devices as templates, we developed a processing route to obtain mechanically robust microcapsules exhibiting a porous shell structure with controlled permeability. The porous shell consists of a network of interconnected polymer particles that are formed upon phase separation within the oil phase of the double emulsion. Porosity is generated by an inert diluent incorporated in the oil phase. The use of undecanol and butanol as inert diluents allows for the preparation of microcapsules covering a wide range of shell-porosity and force-at-break values. We found that the amount and chemical nature of the diluent influence the shell porous structure by changing the mechanism of phase separation that occurs during polymerization. In a proof-of-concept experiment, we demonstrate that the mechanically robust microcapsules prepared through this simple approach can be utilized for the on-demand release of small molecules using a pH change as exemplary chemical trigger.

Hierarchically porous materials: synthesis strategies and structure design

This review addresses recent advances in synthesis strategies of hierarchically porous materials and their structural design from micro-, meso- to macro-length scale.

One-Step Generation of Cell-Encapsulating Compartments via Polyelectrolyte Complexation in an Aqueous Two Phase System

Diverse fields including drug and gene delivery and live cell encapsulation require biologically compatible encapsulation systems. One widely adopted means of forming capsules exploits cargo-filled microdroplets in an external, immiscible liquid phase that are encapsulated by a membrane that forms by trapping of molecules or particles at the drop surface, facilitated by the interfacial tension. To eliminate the potentially deleterious oil phase often present in such processes, we exploit the aqueous two phase system of poly(ethylene glycol) (PEG) and dextran. We form capsules by placing dextran-rich microdroplets in an external PEG-rich phase. Strong polyelectrolytes present in either phase form complexes at the drop interface, thereby forming a membrane encapsulating the fluid interior. This process requires considerable finesse as both polyelectrolytes are soluble in either the drop or external phase, and the extremely low interfacial tension is too weak to provide a strong adsorption site for these molecules. The key to obtaining microcapsules is to tune the relative fluxes of the two polyelectrolytes so that they meet and complex at the interface. We identify conditions for which complexation can occur inside or outside of the drop phase, resulting in microparticles or poor encapsulation, respectively, or when properly balanced, at the interface, resulting in microcapsules. The resulting microcapsules respond to the stimuli of added salts or changes in osmotic pressure, allowing perturbation of capsule permeability or triggered release of capsule contents. We demonstrate that living cells can be sequestered and interrogated by encapsulating Pseudomonas aeruginosa PAO1 and using a Live/Dead assay to assess their viability. This method paves the way to the formation of a broad variety of versatile functional membranes around all aqueous capsules; by tuning the fluxes of complexing species to interact at the interface, membranes comprising other complexing functional moieties can be formed.

Core-Shell Chitosan Microcapsules for Programmed Sequential Drug Release

A novel type of core-shell chitosan microcapsule with programmed sequential drug release is developed by the microfluidic technique for acute gastrosis therapy. The microcapsule is composed of a cross-linked chitosan hydrogel shell and an oily core containing both free drug molecules and drug-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles. Before exposure to acid stimulus, the resultant microcapsules can keep their structural integrity without leakage of the encapsulated substances. Upon acid-triggering, the microcapsules first achieve burst release due to the acid-induced decomposition of the chitosan shell. The encapsulated free drug molecules and drug-loaded PLGA nanoparticles are rapidly released within 60 s. Next, the drugs loaded in the PLGA nanoparticles are slowly released for several days to achieve sustained release based on the synergistic effect of drug diffusion and PLGA degradation. Such core-shell chitosan microcapsules with programmed sequential drug release are promising for rational drug delivery and controlled-release for the treatment of acute gastritis. In addition, the microcapsule systems with programmed sequential release provide more versatility for controlled release in biomedical applications.

Composite hydrogels of polyacrylamide and crosslinked pH-responsive micrometer-sized hollow particles

Whilst hydrogels and hollow particles both continue to attract much attention in the literature there are few examples of hydrogel composites containing hollow particles. Here, we study composite polyacrylamide (PAAm) hydrogels containing micrometer-sized pH-responsive shell-crosslinked hollow particles (abbreviated as HPXL) based on poly(methylmethacrylate-co-methacrylic acid) functionalised with glycidyl methacrylate (GMA). The HPXL particles were prepared using our scaleable emulsion template method and inclusion of GMA was found to promote spherical hollow particle formation. The pendant vinyl groups from GMA enabled shell-crosslinked hollow particles to be prepared prior to formation of the PAAm/HPXL composite gels. The morphologies of the particles and composite gels were studied by optical microscopy, confocal laser scanning microscopy and scanning electron microscopy. Dynamic rheology measurements for the composite gels showed that the modulus variation with HPXL concentration could be described by a percolation model with a HPXL percolation threshold concentration of 4.4 wt% and a scaling exponent of 2.6. The composite gels were pH-responsive and largely maintained their mechanical properties over the pH range 4.0 to 8.0. Because the composite gels had tuneable mechanical properties (with modulus values up to 530 kPa) and were pH-responsive they are potential candidates for future wound healing or membrane applications.

pH-Responsive nanocapsules from silylated copolymers

We introduce here a concept allowing the synthesis of smart nanocapsules without a surfactant.

A smart poly(aniline-formaldehyde) microcapsule based self-healing anticorrosive coating

Schematic representation of the synthesis procedure to obtain poly(aniline-formaldehyde) microcapsules and the mechanism of self healing on mild steel substrate.

Water soluble stimuli-responsive star copolymers with multiple encapsulation and release properties

Stimuli-responsive, water soluble, nontoxic, star-copolymers showing reversible encapsulation and release of hydrophobic dye/drug molecule with increasing temperature and decreasing pH.

Preparation of IL-loaded microreactors based on polyelectrolyte microcapsules

Encapsulation of ionic liquids (ILs) in crosslinked polyelectrolyte microcapsules, made via layer-by-layer assembly (LbL) was successfully conducted. Two different ILs were studied: 1-butyl-3-methylimidazolium tetrafluoroborate [Bmim]BF4 and 1-butyl-3-methylimidazolium hexafluorophosphate [Bmim]PF6. The polyelectrolyte microcapsules were successfully used as microcages for the synthesis of poly(methylmethacrylate) (PMMA), a non water-soluble polymer, in IL medium. Finally, the behaviour of the IL-loaded microreactors in polar and apolar solvents was evaluated. The strategies described in this study offer new routes for the preparation of microreactors incorporating IL which are of interest for many applications in the field of organic synthesis, catalysis and adsorption of active substances.

Microfluidic Assisted Synthesis of Multipurpose Polymer Nanoassembly Particles for Fluorescence, LSPR, and SERS Activities

Potential biomedical applications such as controlled delivery with sustained drug release profile demand for multifunctional polymeric particles of precise chemical composition and with welldefined physicochemical properties. The real challenge is to obtain the reproducible and homogeneous nanoparticles in a minimum number of preparation steps. Here, single-step nanoarchitectures of soft surface layered copolymer nanoparticles with a regular tuning in the size via micro flow-through assisted synthesis are reported. Interfacial copolymerization induces the controlled compartmentalization where a hydrophobic core adopts spherical shape in order to minimize the surface energy and simultaneously shelter in the hydrophilic shelllike surface layer. Surface layer can swell in the aqueous medium and allow controlled entrapping of functional hydrophobic nanoparticles in the hydrophilic interior via electrostatic interaction which can be particularly interesting for combined fluorescence activity. Furthermore, the nanoarchitecture of size and concentration controlled polymer-metal nanoassembly particles can be implemented as an ideal surface-enhanced Raman scattering substrate for detection of the trace amounts of various analytes.

Preparation and characterization of enzyme-responsive emamectin benzoate microcapsules based on a copolymer matrix of silica–epichlorohydrin–carboxymethylcellulose

Novel enzyme-responsive emamectin benzoate microcapsules with remarkable loading ability and photo- and thermal stability were prepared for sustained crop protection.

pH-responsive ion transport in polyelectrolyte multilayers of poly(diallyldimethylammonium chloride) (PDADMAC) and poly(4-styrenesulfonic acid-co-maleic acid) (PSS-MA) bearing strong- and weak anionic groups

We describe the creation of interfacial architectures displaying pH-dependent ionic transport properties which until now have not been observed in polyelectrolyte multilayers.

A synthetic approach towards micron-sized smectic liquid crystal capsules via the diffusion controlled swelling method

Micron-sized smectic liquid crystal encapsulated poly(methyl methacrylate) capsules were synthesized via emulsion polymerization using a diffusion-controlled swelling method.

Development of Self-Healing Coatings Based on Linseed Oil as Autonomous Repairing Agent for Corrosion Resistance

In recent years corrosion-resistant self-healing coatings have witnessed strong growth and their successful laboratory design and synthesis categorises them in the family of smart/multi-functional materials. Among various approaches for achieving self-healing, microcapsule embedment through the material matrix is the main one for self-healing ability in coatings. The present work focuses on optimizing the process parameters for developing microcapsules by in-situ polymerization of linseed oil as core and urea-formaldehyde as shell material. Characteristics of these microcapsules with respect to change in processing parameters such as stirring rate and reaction time were studied by using optical microscopy (OM), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The effectiveness of these microcapsules in coatings was characterized by studying their adhesion, performance, and mechanical properties.