Precipitation Polymerization Research Articles

Synthesis of novel magnetic carboxyl-functionalized crosslinked copolymer microspheres for methylene blue removal from water

Magnetic carboxyl-functionalized crosslinked copolymer microspheres of α-methyl styrene and maleic anhydride (MCPMs) with a uniform particle size were synthesized based on self-stabilized precipitation polymerization. Magnetic crosslinked copolymer microspheres (MPMs) were prepared by in situ polymerization using oleic acid-modified Fe3O4 as the magnetic source, α-methyl styrene and maleic anhydride as monomers and divinylbenzene as the crosslinking agent, and MCPMs were then obtained by hydrolyzing the anhydride groups of MPMs into carboxyl groups. The as-prepared MCPMs were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, vibrating sample magnetometry and the Brunauer–Emmett–Teller method. The adsorption behavior, adsorption kinetics and adsorption isotherms of MCPMs for methylene blue (MB) removal from water were systematically investigated. It was found that MCPMs manifested good MB removal ability from water with a maximum MB adsorption capacity of 315 mg/g. The kinetic and isothermal data of MCPMs for MB removal followed the pseudo-second-order model and the Langmuir isothermal model, respectively. In addition, MB-loaded MCPMs could be separated easily by magnets, and the MB removal rate of MCPMs still reached more than 90.0% after five cycles. These results indicate that MCPMs have great potential in cationic dye wastewater treatments.

Effect of Polymer Network Architecture on Adsorption Kinetics at Liquid-Liquid Interfaces: A Comparison Between Poly(NIPAM-co-AA) Copolymer Microgels and Interpenetrating Network Microgels.

Understanding the adsorption features of polymer microgels with different chemical compositions and structures is crucial in studying the mechanisms of respective emulsion stabilization. Specifically, the use of stimuli-responsive particles can introduce new properties and broaden the application range of such complex systems. Recently, we demonstrated that emulsions stabilized by microgels composed of interpenetrating networks (IPNs) of poly-N-isopropylacrylamide (PNIPAM) and polyacrylic acid (PAA) exhibit higher colloidal stability upon heating compared to PNIPAM homopolymer and other relevant PNIPAM-based copolymer counterparts. In the present work, using pendant drop tensiometry, we studied the evolution of water-tetradecane interfacial tension during the adsorption of PNIPAM-PAA IPN particles, comparing them with single-network P-(NIPAM-co-AA) and PNIPAM microgels. The results showed that, despite having the same chemical composition, copolymer particles exhibit completely different adsorption behavior in comparison to other microgel architectures. The observed disparity can be attributed to the nonuniform distribution of charged acrylic acid groups within the P-(NIPAM-co-AA) network obtained through precipitation polymerization. Oppositely, the presence of IPN architecture provides a uniform distribution of different monomers inside respective microgels. Additionally, hydrogen bonding between PNIPAM and PAA subchains appears to reduce the electrostatic energy barrier, enhancing the ability of IPN particles to successfully cover the liquid interface. Overall, our findings confirm the efficiency of using PNIPAM-PAA IPN microgels for the preparation of oil-in-water emulsions and their stability, even when the temperature rises above the lower critical solution temperature of PNIPAM.

Influence of polymer and surfactant-based precipitation inhibitors on supersaturation-driven absorption of Ibrutinib from high-dose lipid-based formulations.

There is a growing pharmaceutical interest in supersaturated lipid-based formulations (Super-LbF) as an innovative strategy to enhance drug loading capacities while simultaneously reducing pill burden. This approach involves increasing the drug concentration above its equilibrium solubility in a lipid solution, achieved through temperature-induced supersaturation or the dissolution of lipophilic ionic salts. However, the physical instability and potential drug precipitation upon the dispersion of LbF remain critical. The focus of this work was to assess the impact of polymer and surfactant as precipitation inhibitors (PIs) in Super-LbF and investigate whether PIs can effectively address the aforementioned challenges. Ibrutinib (Ibr) was selected as a model drug due to its limited solubility and dissolution characteristics. The optimized formulations were characterized with a focus on dispersibility, lipolysis-permeation, and physical stability during storage. The inclusion of PIs in Super-LbF significantly enhanced physical stability by increasing viscosity and reducing the degree of supersaturation through elevated equilibrium solubility. During the dispersion and digestion study, varying levels of transient supersaturation were observed for both Super-LbF and PI-loaded Super-LbF. A noteworthy 2.5 to 3-fold increase in the solubilization ratio was observed for PI-loaded Super-LbF in comparison to Super-LbF without PI. This increase indicates a significant rise in transient drug supersaturation through kinetic and thermodynamic precipitation inhibition mechanisms. Moreover, lipolysis-permeation studies revealed increased flux values with enhanced solubilization, except in the case of Pluronic® F68, which exhibited a reduced free drug concentration near the Permeapad® barrier. Further, the in vivo absorption study confirmed that prolonged supersaturation, facilitated by PIs, contributed to enhancement in drug exposure in rats. PI-loaded Super-LbFs demonstrated a significant improvement (5.1 to 8.9-fold) in the absorption profile compared to Super-LbF without PI (p<0.001). The study results indicate that incorporating PIs into Super-LbF enhances physical stability and maintains transient drug supersaturation under digestive conditions. Overall, this formulation approach shows promise for expanding the application of LbF to enable the successful oral delivery of high-dose regimen drugs.

Polycyclic aromatic polymer nanoparticles show potent infectious particle adsorption capability.

Nonspecific viral adsorption by polymer nanoparticles is more economical and superior in terms of operating cost and energy efficiency than viral adsorption using virus-specific antibodies and filtration techniques involving size exclusion in the order of tens of nanometres. In this study, we synthesised four types of polycyclic aromatic polymer (ArP) nanoparticles with different structures and evaluated their virus adsorption capability for infectious particles of the newly emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). ArP nanoparticles with a diameter of approximately 500 nm were prepared by one-pot precipitation polymerisation using structural isomers of bifunctional dihydroxynaphthalene (1,5-dihydroxynaphthalene and 2,6-dihydroxynaphthalene) as phenol monomers, as well as 3-hydroxybenzoic acid and 3-aminophenol as comonomers to introduce carboxylic acid and amino groups, respectively. This wide range of phenolic monomers offers a powerful molecular design capability, enabling the optimisation of surface properties for the adsorption of various infectious virus particles. The virus adsorption capacity of the ArP nanoparticles exceeded 20 000 plaque-forming units and was found to be correlated with the nitrogen (primary and secondary amines) and quinone contents on the ArP nanoparticle surface. Furthermore, a polyvinylidene difluoride membrane filter uniformly coated with the ArP nanoparticles could remove viruses by filtration in a flow system.

Influence of Composition on the Patterns of Electrokinetic Potential of Thermosensitive N-(Isopropyl)Acrylamide Derivatives with Poly(Ethylene Glycol) Dimethacrylate and N-(2-Hydroxyethyl)Acrylamide.

The synthesis of poly(N-isopropyl acrylamide) (pNIPA)-based polymers via the surfactant-free precipitation polymerization (SFPP) method produced thermosensitive nanospheres with a range of distinctive physicochemical properties. Nano- and microparticles were generated using various initiators, significantly influencing particle characteristics, including the hydrodynamic diameter (DH), which varied from 87.7 nm to 1618.1 nm. Initiators, such as potassium persulfate and 2,2'-azobis(2-methylpropionamidine) dihydrochloride, conferred anionic and cationic functionalities, respectively, impacting the electrokinetic potential (EP) of the particles. Notably, certain particles with cationic initiators exhibited negative EP values at 18 °C, attributed to residual initiator components that affected the surface charge distribution. The presence of hydrophilic N-(2-hydroxyethyl)acrylamide (HEAA) segments also influenced solubility and phase transition behaviors, with critical dependencies on the HEAA/NIPA (N-isopropyl acrylamide) molar ratios. EP measurements taken at 18 °C and 42 °C revealed substantial differences, primarily governed by the initiator type and polymer composition. Observed variations in particle stability and size were associated with the choice of crosslinking agents and comonomer content, which affected both DH and EP in distinct ways. This study provides insights into key factors influencing colloidal stability and electrostatic interactions within thermosensitive polymer systems, underscoring their potential applications in biomedical and industrial fields.

MXene-Vitrimer Nanocomposites: Photo-Thermal Repair, Reinforcement, and Conductivity at Low Volume Fractions Through a Percolative Voronoi-Inspired Microstructure.

An innovative process to multifunctional vitrimer nanocomposites with a percolative MXene minor phase is reported, marking a significant advancement in creating stimuli-repairable, reinforced, sustainable, and conductive nanocomposites at diminished loadings. This achievement arises from a Voronoi-inspired biphasic morphological design via a straight-forward three-step process involving ambient-condition precipitation polymerization of micron-sized prepolymer powders, aqueous powder-coating with 2D MXene (Ti3C2Tz), and melt-pressing of MXene-coated powders into crosslinked films. Due to the formation of MXene-rich boundaries between thiourethane vitrimer domains in a pervasive low-volume fraction conductive network, a low percolation threshold (≈0.19vol.%) and conductive polymeric nanocomposites (≈350 Sm-1) are achieved. The embedded MXene skeleton mechanically bolsters the vitrimer at intermediate loadings, enhancing the modulus and toughness by 300% and 50%, respectively, without mechanical detriment compared to the neat vitrimer. The vitrimer's dynamic-covalent bonds and MXene's photo-thermal conversion properties enable repair in minutes through short-term thermal treatments for full macroscopic mechanical restoration or in seconds under 785nm light for rapid localized surface repair. This versatile fabrication method to nanocoated pre-vitrimer powders and morphologically complex nanocomposites is compatible with classic composite manufacturing, and when coupled with the material's exceptional properties, holds immense potential for revolutionizing advanced composites and inspiring next-generation smart materials.

Precipitation Polymerization-Based Molecularly Imprinted Polymers: A Novel Approach for Transdermal Curcumin Delivery.

This research describes the synthesis and characterization of a molecularly imprinted polymer (MIP) as a candidate for the transdermal delivery of curcumin. The MIP was synthesized through precipitation polymerization using methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linking agent. MIP characterization studies were conducted using SEM-EDX and FTIR spectroscopy to determine the morphology and interaction between curcumin and polymers. The MIP obtained through precipitation polymerization was in the form of a fine powder with a surface morphology resembling a collection of small granules with a uniform shape. The adsorption capacity of the MIP follows the Langmuir adsorption isotherm model, with a maximum capacity of 4.239 mg/g, which is greater than that of the NIP (3.219 mg/g), resulting in an imprinting efficiency of 1.317. The percentage of curcumin released from the MIP after 8 h was 41.26%, which is lower than that from the NIP, at 51.50%. The drug release kinetics study follows the Higuchi model, indicating drug diffusion from the polymer matrix. Imprinting on the MIP can modify drug diffusion from the polymer matrix, resulting in a reduced release rate in the MIP. Therefore, the MIP can be considered a candidate for the controlled transdermal delivery of curcumin.

Chemical factors affecting the wetting time of poly(acrylic acid) xerogel powder synthesized by precipitation polymerization technique

Chemical factors affecting the wetting time of poly(acrylic acid) xerogel powder synthesized by precipitation polymerization technique

Molecularly imprinting polymethacrylamide onto Cu-based metal-organic framework as a pH-sensitive core-shell nanocarrier for potential anti-cancer drug delivery.

Surface molecularly imprinted polymers (MIPs) are an efficient and rapidly advancing approach, increasingly being utilized in drug delivery systems (DDSs). This research involved synthesizing a core-shell structure, consisting of a metal-organic framework (MOF) core and a doxorubicin (DOX) imprinted polymethacrylamide shell, prepared via precipitation polymerization method in green media. The resulting MOF@MIP was utilized as a nanocarrier for DOX delivery, exhibiting high drug loading capacity and pH responsiveness delivery. The materials were characterized using different techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared (FTIR), transmission electron microscopy (TEM), dynamic light scattering (DLS), thermal gravimetric analysis (TGA), and zeta potential (ZP). In vitro studies on DOX loading and release demonstrated that a higher amount of DOX was released in a sustained manner under tumor tissue conditions (pH 5, 41 °C) compared to normal physiological conditions (pH 7.4, 37 °C). Additionally, cytotoxicity evaluations revealed significant cytotoxic effects of DOX-loaded MOF@MIP on MCF-7 cells (IC50: 2 μg/mL). Based on these findings, the synthesized MOF@MIP shows promise as a potential candidate for the development of anticancer therapeutic delivery platforms.

Efficient synthesis of narrow or monodisperse, physically cross-linked, and “living” spherical polymer particles via one-stage ambient temperature photoiniferter-RAFT precipitation polymerization and its particle formation mechanism

Efficient synthesis of narrow or monodisperse, physically cross-linked, and “living” spherical polymer particles via one-stage ambient temperature photoiniferter-RAFT precipitation polymerization and its particle formation mechanism

Supersaturation Behavior: Investigation of Polymers Impact on Nucleation Kinetic Profile for Rationalizing the Polymeric Precipitation Inhibitors.

Although nucleation kinetic data is quite important for the concept of supersaturation behavior, its part in rationalizing the crystallization inhibitor has not been well understood. This study aimed to investigate the nucleation kinetic profile of Dextromethorphan HBr (as an ideal drug, BCS-II) by measuring liquid-liquid phase segregation, nucleation induction time, and Metastable Zone width. Surfeit action was examined by a superfluity assay of the drug. The concentration was scrutinized by light scattering techniques (UV spectrum (novel method) and Fluorometer (CL 53)). The drug induction time was 20 min without polymer and 90 and 110 min with polymers, such as HPMC K15M and Xanthan Gum, respectively. Therefore, the order of the polymer's ability to inhibit nucleation was Xanthan Gum > HPMC K15M in the medium (7.4 pH). Similarly, the drug induction time was 30 min without polymer and 20, 110, and 90 min with polymers, such as Sodium CMC, HPMC K15M, and Xanthan Gum, respectively. Therefore, the order of the polymer's ability to inhibit nucleation was HPMC K15M > Xanthan Gum > Sodium CMC in SIFsp (6.8 pH), which synchronizes the polymer's potentiality to interdict the drug precipitation. The HPMC K15M and xanthan Gum showed the best crystallization inhibitor effect for the maintenance of superfluity conditions till the drug absorption time. The xanthan gum is based on the "glider" concept, and this shows the novelty of this preliminary research. The screening methodology used for rationalizing the best polymers used in the superfluity formulations development successfully.

ChromEMT: visualizing and reconstructing chromatin ultrastructure and 3D organization in situ.

Structure determines function. The discovery of the DNA double-helix structure revealed how genetic information is stored and copied. In the mammalian cell nucleus, up to two meters of DNA is compacted by histones to form nucleosome/DNA particle chains that form euchromatin and heterochromatin domains, chromosome territories and mitotic chromosomes upon cell division. A critical question is what are the structures, interactions and 3D organization of DNA as chromatin in the nucleus and how do they determine DNA replication timing, gene expression and ultimately cell fate. To visualize genomic DNA across these different length scales in the nucleus, we developed ChromEMT, a method that selectively enhances the electron density and contrast of DNA and interacting nucleosome particles, which enables nucleosome chains, chromatin domains, chromatin ultrastructure and 3D organization to be imaged and reconstructed by using multi-tilt electron microscopy tomography (EMT). ChromEMT exploits a membrane-permeable, fluorescent DNA-binding dye, DRAQ5, which upon excitation drives the photo-oxidation and precipitation of diaminobenzidine polymers on the surface of DNA/nucleosome particles that are visible in the electron microscope when stained with osmium. Here, we describe a detailed protocol for ChromEMT, including DRAQ5 staining, photo-oxidation, sample preparation and multi-tilt EMT that can be applied broadly to reconstruct genomic DNA structure and 3D interactions in cells and tissues and different kingdoms of life. The entire procedure takes ~9 days and requires expertise in electron microscopy sample sectioning and acquisition of multi-tilt EMT data sets.

Catalytic degradation of various dyes using silver nanoparticles fabricated within chitosan based microgels

Precipitation polymerization method was used to synthesize chitosan based poly[chitosan-N-isopropylmethacrylamide-acrylic acid] [P(CS-NI-AA)] microgel particles. Synthesized P(CS-NI-AA) microgel particles were utilized as micro-reactors for the fabrication of silver nanoparticles (AgNPs) inside the structure of microgels through chemical reduction of Ag+ ions using NaBH4 as reducing agent. P(CS-NI-AA) and Ag-P(CS-NI-AA) systems were analyzed using various characterization techniques like scanning electron microscopy (SEM), ultraviolet-visible (UV–visible) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Catalytic activity of Ag-P(CS-NI-AA) for individual and simultaneous degradation of various dyes like methylene blue (MB), Congo red (CR), brilliant blue (Bb), methyl orange (MO) and Rhodamine B (RB) was investigated in aqueous phase using NaBH4 as reductant. The Pseudo 1st order rate constant (k1) for dyes degradation were evaluated. The Ag-P(CS-NI-AA) hybrid system was observed to be efficient, low-cost and stable catalyst for quick degradation of dyes.

Mechanics-Switchable and Antiswelling Colloidal Hydrogels Inspired by the Cononsolvency Effect.

Stiffness switching hydrogels have been in high demand for intelligent devices, adhesion science, soft robotics, and flexible electronics. However, it is challenging to post-tune the mechanical properties of a hydrogel once the polymer network structure is formed. Inspired by the cononsolvency effect, we prepared a mechanics-switching colloidal hydrogel through the precipitation polymerization of methacrylamide in mixed dimethyl sulfoxide and water solvents. The colloidal network enables the hydrogels to simultaneously strengthen, stiffen, and toughen. The colloidal hydrogels not only display a broad spectrum of adjustable mechanical properties (ranging from 0.08 to 57.1 MPa) via solvent response but also accomplish reversible stiffness conversion through the solvent-tuned conformational adjustment of colloidal polymer networks, with the maximum modulus conversion reaching 1427, and exhibit solvent-responsive shape memory. Based on the stable and tight colloidal network, the hydrogels exhibit antiswelling properties in various aqueous solutions and solvents. The colloidal hydrogel would provide more possibilities in various applications, such as antiimpact protection, shape memory, electronic switches, and intelligent engineering materials. It is envisioned that this work will provide key opportunities in developing mechanics-switching and on-demand tuning of soft materials for tissue engineering, flexible electronics, and biomedical science.

Uniform Polymer Microspheres by Photoinduced Metal-Free Atom Transfer Radical Precipitation Polymerization.

Herein, a photoinduced method is introduced for the synthesis of highly cross-linked and uniform polymer microspheres by atom transfer radical polymerization (ATRP) at room temperature and in the absence of stabilizers or surfactants. Uniform particles are obtained at monomer concentrations as high as 10% (by volume), with polymers being exempt from contamination by residual transition metal catalysts, thereby overcoming the two major longstanding problems associated with thermally initiated ATRP-mediated precipitation polymerization. Moreover, the obtained particles have also immobilized ATRP initiators on their surface, which directly enables the controlled growth of densely grafted polymer layers with adjustable thickness and a well-defined chemical composition. The method is then employed successfully for the synthesis of molecularly imprinted polymer microspheres.

Reversible Addition-Fragmentation Chain-Transfer Polymerization in Supercritical CO2: A Review.

The development of cleaner, more environmentally friendly processes in polymerization technology is crucial due to the prevalent use of volatile organic solvents (VOCs), which are harmful and toxic. Future regulations are likely to limit or ban VOCs. This review explores the use of supercritical solvents, specifically supercritical CO2 (scCO2), in polymerization processes. The study focuses on reversible addition-fragmentation chain-transfer (RAFT) induced homo-polymerization of various monomers using specific chain transfer agents (CTAs) in scCO2. RAFT polymerization, a reversible deactivation radical polymerization (RDRP) polymerization, relies heavily on the choice of CTA, which significantly influences the dispersity and molar mass of the resulting polymers. Stabilizers are also crucial in controlling product specifications for polymerizations in supercritical CO2, except for fluor-based polymers, although they must be removed and preferably recycled to ensure product purity and sustainability. The review notes that achieving high molar mass through RAFT polymerization in scCO2 is challenging due to solubility limits, which lead to polymer precipitation. Despite this, RAFT polymerization in scCO2 shows promise for sustainable, circular production of low molar mass polymers, although these cannot yet be fully considered green products.

Poly(N-isopropylacrylamide)-chitosan nanogels for nanotechnological and catalytic applications

Polymer nanogels consisting of poly(N-isopropylacrylamide) and chitosan [P(NC)] were synthesized using a free radical precipitation polymerization technique in an aqueous environment. This process involved the polymerization of N-isopropylacrylamide (NIPAAM) with chitosan (CS) and a cross-linker. These P(NC) nanogels were utilized as nano-reactors for the synthesis of gold nanoparticles (AuNPs), which were formed within the polymeric network through an in-situ reduction process using tetrachloroauric acid [H(AuCl4)] as precursor salt and sodium borohydride (NaBH4) as the reductant. Various analytical methods, including Transmission electron microscopy (TEM), Thermogravimetric analysis (TGA), Ultraviolet–visible spectroscopy (UV–Vis), and Fourier transform infrared spectroscopy (FTIR), were employed to confirm the formation of P(NC) nanogels and the incorporation and durability of AuNPs within the P(NC) nanogels. The AuNPs loaded P(NC) nanogels were utilized as catalysts for the reduction of 4-nitrophenol (4-NiP) into 4-aminophenol (4-AmP) in the presence of NaBH4. This system was also used to degrade a number of dyes including methylene blue (MB), methylene orange (MO), rhodamine B (RhB), brilliant blue (BB) and eosin Y ((EY) by using NaBH4 as a reducing agent. The Au-P(NC) catalyst exhibited remarkable efficiency, facilitating the fast reduction of 4-NiP and degradation of dyes within a very short interval of time. This system stands out for its economic usage, as even a small quantity of it can efficiently reduce toxic pollutants like 4-NiP and dyes. The results of the reactions highlighted exceptional yield, emphasizing the effectiveness and recyclability of the Au-P(NC) hybrid nanogels as highly capable catalysts.

Structural Evolution of Microgels During Precipitation Polymerization Revealed by Light Scattering and Electrophoresis

AbstractWhile precipitation polymerization allows the synthesis of microgels with controlled functional‐group distributions, the structural development of these microgels during the polymerization process still remains unclear. In this study, microgels with different reactivity ratios between the monomer and charged co‐monomer are prepared by precipitation polymerization, and the evolution of their size, thermoresponsive behavior, and surface properties during polymerization are evaluated. In particular, the surface properties of the microgels are analyzed quantitatively using the softness parameter and the surface charge density is calculated using Ohshima's equation. The results allowed describing the structural changes of microgels during precipitation polymerization well and provided design guidelines for functional microgels with controlled functional group distributions.

Analysis of Trace Enrofloxacin in Environmental Waters by a Surface Molecular Imprinting Technique.

Surface-imprinted polymers (ZIF-67@MIPs) supported by ZIF-67 were prepared by precipitation polymerization using enrofloxacin (ENR) as the template molecule, methacrylic acid as the functional monomer, and ethylene glycol dimethacrylate as the cross-linker. ZIF-67@MIPs were characterized by Fourier transform infrared spectrometry, X-ray diffraction, scanning electron microscopy, and particle size distribution. The adsorption performance of the polymer was studied. The adsorption equilibrium was reached within 30 min. The maximum adsorption was 9.02 μg·mg-1. The imprinting factor was 2.58. The polymer was then used as a sorbent of a solid-phase extraction column for the separation and purification of ENR in real water samples. The extraction conditions were optimized. The method was established by high-performance liquid chromatography, and the linearity was verified by UPLC-MSMS. The correlation coefficient and limits of detection and quantification were 0.9999, 0.23 ng·mL-1, and 0.76 ng·mL-1, respectively. The recoveries were in the range of 83.79-100.68%; the relative standard deviation was 4.46-7.35%. The above data indicated that the method could be used for the separation and enrichment of ENR in real samples.

Encapsulation of Liquids via Polymer Precipitation in Emulsions

ABSTRACTMicroencapsulation strategies enable the confinement of sensitive active materials in a protective shell, giving capsules with applications across pharmaceuticals, foodstuffs, agriculture, textiles, cosmetics, and energy storage. Among the different approaches, the soft template encapsulation method is a widely used technique that leverages emulsions as templates and forms spherical microcapsules with a liquid core and polymeric shell. Within the emulsion template umbrella, interfacial polymerization, phase internal phase separation, and polymer precipitation can all be used. The main limitation of interfacial polymerization is that the core will inevitably contain impurities such as residual monomers, which can affect the performance of the encapsulated material. This is especially relevant when performance efficiency strongly depends on its pristine composition. In this perspective, we focus on polymer precipitation soft‐template strategies for capsule formation, and the complementarity of this approach to the more widely used interfacial polymerization. Polymer precipitation strategies enable the encapsulation of sensitive cores (or payloads) and can include those that are viscous, hygroscopic, and reactive.