Influence of urea on the coloring ability of a low‐temperature coloring method of keratin fibers using polyethyleneimine

For the purpose of improving the coloring ability of keratin fibers at a lower temperature, we investigated the influence of urea on the coloring ability of a low‐temperature coloring method using polyethyleneimine (PEI) as a counter ion reagent (the human hair was previously treated with a PEI solution, and then was colored with acid dye). The coloring and color fastness to shampooing of the hair pretreated with a PEI solution containing urea clearly improved compared with those pretreated with a PEI solution not containing urea. Also, we prepared cross‐sectional samples of the treated hair and investigated the penetration of PEI and Orange II into human hair by optical microscopy. The results showed that the penetration of PEI and Orange II into human hair pretreated with a PEI solution that contained urea clearly increased compared with those pretreated with a PEI solution that did not contain urea. From these experiments, we concluded that urea acts as a penetration accelerator for PEI; and PEI, which penetrates deeper into human hair by adding urea, exerts counter ionization on Orange II, thus increasing the penetration of Orange II into human hair and thereby improving the coloring ability. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3827–3834, 2004     

Diffusion behavior of reducing agents into keratin fibers using microspectrophotometry

To investigate the penetration of thioglycolic acid (TG), thiolactic acid (TL), and L ‐cysteine (CYS), into keratin fibers, cross‐sectional samples of virgin white human hair treated with TG, TL, and CYS were prepared. A new method for analyzing the diffusion behavior of reducing agents into human hair was developed. The diffusion pattern of reducing agents into human hair, which cannot be determined by optical microscopy, can be determined by the method developed. The method involves treating virgin hair fibers with TG, TL, and CYS. After the treatment, the cross‐sectioned hair samples were dyed with methylene blue and the cross‐sectional intensity scans were measured at a wavelength of 664 nm (λ_max of methylene blue) with a microspectrophotometer. The three different diffusion patterns from the three reducing agents were obtained. The penetration of TG and TL into virgin human hair clearly increased by increasing the treatment time and pH. On the other hand, the penetration of CYS was less than TG and TL (CYS could not penetrate into the cortex region of the virgin human hair). Also, the diffusion pattern of TG showed Fickian type characteristics. The apparent diffusion coefficient of TG into human hair at pH 9.0 determined from the TG concentration profile was found to be 10^?9 cm²/s. On the other hand, the apparent diffusion coefficient of TG into human hair at pH 7.0 was 10^?10 cm²/s, and thus, the apparent diffusion coefficient of TG depended on the pH of the TG solution. From these experiments, we have concluded that the diffusion patterns of the three reducing agents in this study depended on the electrostatic interaction between the human hair and the reducing agents. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1131–1138, 2004     

New method of dyeing keratin fibers using poly(ethylene imine) and its coloring mechanism

To improve the colorability of keratin fibers at lower temperatures, we developed a novel coloring method using poly(ethylene imine) (PEI) as a counterion reagent (human hair was treated beforehand with a PEI solution and then was colored with an acid dye). As a result of this new method, the coloring and color fastness to shampooing clearly improved with respect to the usual method. Next, to study the coloring mechanism with PEI, we investigated the penetration of PEI and Orange II into bleached human hair by optical microscopy. The results showed that the penetration of PEI and Orange II into bleached human hair increased with an increasing PEI treatment time and with a decreasing PEI molecular weight. With these experiments, we demonstrated that PEI, which penetrated the cortex region, exerted counterionization on Orange II, thereby increasing the penetration of Orange II into bleached human hair. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3806–3810, 2003     

Raman spectroscopic analysis of L‐phenylalanine and hydrolyzed eggwhite protein penetration into keratin fibers

To investigate the penetration of amino acids and hydrolyzed protein derived from eggwhites (HEWP) into keratin fibers, the structure of cross‐sectional samples at various depths of virgin white human hair treated with L ‐phenylalanine (Phe) and bleached black human hair treated with HEWP was directly analyzed without isolating the cuticle and cortex using Raman spectroscopy. The hydrophobic amino acids clearly penetrated into the virgin white human hair, while hydrophilic amino acids did not penetrate at all. The Phe hydrophobic amino acid content at various depths of the virgin white hair increased by performing the Phe treatment (at 50°C for 16 h), indicating that Phe deeply penetrated into the virgin human hair. Also, the disulfide (? SS? ) and random coil contents at various depths of the bleached human hair increased by performing the HEWP treatment, indicating that HEWP also deeply penetrated into the bleached human hair. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Dynamic adsorption behaviors between Cu2+ ion and water‐insoluble amphoteric starch in aqueous solutions

Dynamic adsorption behavior between Cu²⁺ ion and water‐insoluble amphoteric starch was investigated. The sorption process occurs in two stages: external mass transport occurs in the early stage and intraparticle diffusion occurs in the long‐term stage. The diffusion rate of Cu²⁺ ion in both stages is concentration dependent. In the external mass‐transport process, the diffusion coefficient (D₁) increases with increasing initial concentration in the low‐ (1 × 10^?3‐4 × 10^?3M) and high‐concentration regions (6 × 10^?3‐10 × 10^?3M). The values of adsorption activation energy (k_d1) in the low‐ and high‐concentration regions are 15.46–24.67 and ?1.80 to ?11.57 kJ/mol, respectively. In the intraparticle diffusion process, the diffusion coefficient (D₂) increases with increasing initial concentration in the low‐concentration region (1 × 10^?3‐2 × 10^?3M) and decreases with increasing initial concentration in the high‐concentration region (4 × 10^?3‐10 × 10^?3M). The k_d2 values in the low‐ and high‐concentration regions are 9.96–15.30 and ?15.53 to ?10.71 kJ/mol, respectively. These results indicate that the diffusion process is endothermic in the low‐concentration region and is exothermic in the high‐concentration region for both stages. The external mass‐transport process is more concentration dependent than the intraparticle diffusion process in the high‐concentration region, and the dependence of concentration for both processes is about equal in the low‐concentration region. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2849–2855, 2001     

Synthesis and biological activity of phthalimide‐based polymers containing 5‐fluorouracil

The attachment of anticancer agents to polymers is a promising approach towards reducing the toxic side‐effects and retaining the potent antitumour activity of these agents. A new tetrahydrophthalimido monomer containing 5‐fluorouracil (ETPFU) and its homopolymer and copolymers with acrylic acid (AA) and with vinyl acetate (VAc) have been synthesized and spectroscopically characterized. The ETPFU contents in poly(ETPFU‐co‐AA) and poly(ETPFU‐co‐VAc) obtained by elemental analysis were 21 mol% and 20 mol%, respectively. The average molecular weights of the polymers determined by gel permeation chromatography were as follows: M_n = 8900 g mol^?1, M_w = 13 300 g mol^?1, M_w/M_n = 1.5 for poly(ETPFU); M_n = 13 500 g mol^?1, M_w = 16 600 g mol^?1, M_w/M_n = 1.2 for poly(ETPFU‐co‐AA); M_n = 8300 g mol^?1, M_w = 11 600 g mol^?1, M_w/M_n = 1.4 poly(ETPFU‐co‐VAc). The in vitro cytotoxicity of the compounds against FM3A and U937 cancer cell lines increased in the following order: ETPFU > 5‐FU > poly(ETPFU) > poly(ETPFU‐co‐AA) > poly(ETPFU‐co‐VAc). The in vivo antitumour activities of all the polymers in Balb/C mice bearing the sarcoma 180 tumour cell line were greater than those of 5‐FU and monomer at the highest dose (800 mg kg^?1). © 2002 Society of Chemical Industry     

In vitro release of complexed pDNA from biodegradable polymer films

The controlled delivery of low‐molecular weight drugs and proteins from biodegradable polymers has received considerable attention. However, controlled release studies of pDNA from such polymers have not been reported to date. In this study, a plasmid DNA was complexed with the cationic polymer called polyethylenimine (PEI). This gene vector has been shown to be very effective in transfecting cells. The complexed DNA were then incorporated into different types of poly‐lactic‐co‐glycolic acid (PLGA) film; PLGA 53/47 (M_w 90 kDa), 50/50 (M_w 11 kDa, end group is lauryl ester) and 75/25 (M_w 120 kDa). Their release profiles from a buffer solution were studied. An initial (small) burst release of PEI‐DNA from film was observed in PLGA 53/47 and 50/50, followed by a plateau phase and finally a rapid erosion‐controlled release. For PLGA 50/50, the rapid release started after 14 days; erosion‐controlled release for PLGA 53/47 started after 9 days; for PLGA 75/25, the release rate was governed by an initial burst release (10%) followed by a slow release controlled by diffusion. No obvious erosion‐controlled release rate was observed for this polymer up to 27 days. Thus, the controlled release of complexed DNA follows the general features exhibited by lower‐ M_w drugs. This is of significance in designing gene vector matrices that offer the promise of more lasting gene therapy compared with particulate formulations. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Polyethylenimine‐functionalized multiwalled carbon nanotube for the adsorption of hydrogen sulfide

Functionalized multiwalled carbon nanotubes (MWCNTs) were synthesized with ethane diamine and polyethylenimine (PEI) with molecular weights of 1800 [MWCNT‐PEI weight‐average molecular weight (M_w) = 1800] and 70,000 (MWCNT‐PEI M_w = 70,000), respectively. The structures and properties of the ethane diamine functionalized MWCNTs and PEI‐functionalized MWCNTs were characterized by Raman spectroscopy, thermogravimetric analysis, X‐ray powder diffraction, and scanning electron microscopy. An increase with the D/G (D, Disorder band; G, Graphite) ratio of the functionalized MWCNTs in the Raman spectra proved that the ethane diamine and PEI were successfully bonded to the surface of the pristine MWCNTs. The results of TGA also confirmed this. In addition, the structure of the functionalized MWCNTs showed no significant changes compared with the pristine MWCNTs; this was confirmed by X‐ray powder diffraction. Hydrogen sulfide (H₂S) sorption on the functionalized MWCNTs was studied by UV spectroscopy. As expected, the results of UV spectroscopy shows that the MWCNTs bonded with higher molecular weight PEI had a more excellent H₂S adsorption efficiency than those bonded with low‐molecular‐weight PEI and ethane diamine, a micromolecular amine. The effects of the pH and temperature on the adsorption of H₂S were also studied. Under the conditions investigated, the maximum first‐time H₂S adsorption efficiency of 1.94 mmol/g was observed for MWCNT‐PEI (M_w = 70,000) in the 60 mg/L sodium hydrosulfide (NaHS) aqueous solution. In addition, the H₂S reversible adsorption of the functionalized MWCNTs was conducted, and the second‐time H₂S adsorption efficiency of MWCNT‐PEI (M_w = 70,000) reached 1.83 mmol/g in the 60 mg/L NaHS aqueous solution. The results demonstrate that the MWCNTs decorated with high‐molecular‐weight PEI were potentially excellent and reversible H₂S adsorbents. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44742.     

Adsorption of Ni2+ from aqueous solutions by novel polyethyleneimine‐attached poly(p‐chloromethylstyrene) beads

In this study Ni²⁺ adsorption properties of polyethyleneimine (PEI)‐attached poly(p‐chloromethylstyrene) (PCMS) beads were investigated. Spherical beads with an average size of 186 μm were obtained by the suspension polymerization of p‐chloromethylstyrene conducted in an aqueous dispersion medium. Owing to the reasonably rough character of the bead surface, PCMS beads had a specific surface area of 14.1 m²/g. PEI chains could be covalently attached onto the PCMS beads with equilibrium binding capacities up to 208 mg PEI/g beads, via a direct chemical reaction between the amine and chloro‐methyl groups. After PEI adsorption with 10% (w/w) initial PEI concentration, free amino content of PEI‐attached PCMS beads was determined as 0.91 mEq/g. PEI‐attached PCMS beads were utilized as adsorbents in the adsorption/desorption of Ni²⁺ ions from synthetic solutions. The adsorption process was fast; 90% of adsorption occurred within 90 min, and equilibrium was reached at around 2 h. Adsorption capacity was obtained to be 78.2 mg/g at a pH of about 6.0. The chelating beads can be easily regenerated by 0.1 M HNO₃ with higher effectiveness. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2467–2473, 2002     

Macroporous bead modification with polyethylenimines of different molecular weights as polycationic ligands

Polyethylenimines (PEIs) with different molecular weights [number‐average molecular weights (M_n′s) = 60,000, 1200, and 423] were coupled onto macroporous beads. These rigid and spherical beads were prepared by the crosslinking of 2‐hydroxyethyl methacrylate and ethylene glycol dimethacrylate. The PEI attachment was carried out through epoxy groups yielded in a previous activation step with epichlorohydrin on matrix hydroxyl groups. Different initial concentrations of PEI were assayed. The supports so obtained were characterized by several techniques (Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and mercury intrusion porosimetry). All of the PEI‐containing beads were used to analyze the influence that the molecular weight, the shape of the polycationic ligand (PEI), and the degree of coupling onto the matrices may have had on the efficiency of the retention of the bovine serum albumin protein used as a model biomolecule. In these assays, the PEI‐modified beads with M_n = 60,000 showed better results than those modified with PEIs with M_n's of 1200 and 423. The presence of sparse and long chains of PEI 60,000 onto the matrix, by reason of their highest accessibility toward the large protein, may have resulted in a better disposition of functional groups, whereas more short chains in the other PEIs (M_n's = 1200 and 423) used as ligands would not have. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Urea/NaOH aqueous solution as new solvent of aeromonas gum

Aeromonas (A) gum, an acidic heteropolysaccharide, formed aggregates easily in NaCl aqueous solution. A novel solvent of the A gum, which can prevent aggregation, was found to be 0.20M urea/0.25M NaOH aqueous solution. The weight‐average molecular weight (M_w), radius of gyration (〈s²〉^1/2), and intrinsic viscosity ([η]) of the samples were determined in 0.20M urea/0.25M NaOH aqueous solution at 25°C by light scattering (M_w, 〈s²〉^1/2) and viscometry ([η]). The values of M_w, 〈s²〉^1/2, and [η] were close to those in 0.20M lithium chloride/dimethylsulfoxide, in which the A gum exists as a semiflexible single chain, implying the same conformation for the A gum in 0.20M urea/0.25M NaOH aqueous solution. The results revealed that 0.20M urea/0.25M NaOH aqueous solution is a good solvent, which effectively avoids the aggregates of the A gum in aqueous solution. Moreover, it can be used to investigate the solution properties and chain conformation of water‐insoluble polysaccharides or the polysaccharides that are easily aggregated in aqueous systems. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1710–1713, 2005     

Boric acid binding studies with diol containing polyethylenimines as determined by 11B NMR spectroscopy

Three water‐soluble polymers incorporating increasing levels of 2,3‐dihydroxy propyl attached to polyethylenimine (PEI) backbone were synthesized, characterized by NMR, and investigated for their ability to bind boric acid (BA). ¹¹B NMR spectroscopy showed that BA interacted with the polymeric 2,3‐dihydroxy propyls by forming borate monoester and borate diesters in the boron concentration range of 100–1000 ppm and at 0.0775M polymer. Borate monoester species predominated for low functionalization levels (33% of the PEI amines functionalized), whereas borate diester species dominated for the higher functionalized polymers (66–100% of the PEI amines functionalized). All three polymers showed that 100% of the BA was bound as a mixture of borate mono‐ and diesters at 100‐ppm boron. The overall best performer based on total borate ester formation was the 2/3‐PEI, with a binding K_d of 631 at 200 ppm boron. Borate ion concentration was measured from the ¹¹B NMR chemical shift of the BA/borate peak and it decreased as 1/3‐PEI > 2/3‐PEI > 3/3‐PEI. Variable temperature ¹¹B NMR showed drastic reduction of borate ester species at 65°C. Thus, PEI polymers, as the ones investigated in this work, are reasonable candidates for the selective recovery and recycle of BA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4411–4418, 2006     

Phase separation of poly(ether sulfone imide) modified epoxy resin

Poly(ether sulfone imide)s (PEI) with molecular weight M_n ∼ 10⁴ were synthesized from 3,3′,4,4′-benzophenone tetracarboxylic dianhydride and amine terminated poly(ether sulfone) having molecular weights ranging from M_n ∼ 400 to M_n ∼ 4000. Thus, the PEIs had the same molecular weight but various imide and ether sulfone contents. The PEIs were mixed with a stoichiometric mixture of diglycidyl ether bis-phenol-A (DGEBA)/diamino diphenyl sulfone (DDS). The effect of PEI on the curing reaction of DGEBA/DDS and the morphology of the polymer blend were studied by differential scanning calorimetry (DSC) and optical microscopy. In the DGEBA/DDS/PEI blend with a fixed PEI molecular weight and PEI concentration but with various imide content, the experimental data revealed the PEI with a higher content of ether sulfone had a lower T_g and a better compatibility with solvents and epoxy resins; the curing reaction rate of DGEBA/DDS/PEI was faster for PEI with a higher imide content; the DSC data of cured DGEBA/DDS/PEI showed two T_gs, indicating phase separation between PEI and cured epoxy resins; and the data of optical microscopy showed that the compatibility of PEI with epoxy resins increased with the content of ether sulfone in PEI. © 1996 John Wiley & Sons, Inc.     

Kinetics of polycondensation of urea with formaldehyde. Molecular weight distribution,average molecular weight,and polydispersity parameters

The molecular weight distribution, molecular weight averages M _n, M _w, M _z, polydisperisty coefficient, statistic standard deviation of number and weight distribution, and Hoseman–Schramek index of the polycondensates of urea with formaldehyde have been estimated. The properties of this solution were obtained by the help of the combination of the following methods: GPC, VPO, turbidimetric titration, and fractional precipitation. The course of the polycondensation described was formally divided in the following stages: (1) formation of methylolated urea derivates and of the lowest oligomers, (2) decrease in the content of methylol urea and in the content of the lowest oligomers with M < 200, and production of soluble molecules between 10³ and 10⁴, and (3) formation of insoluble products.     

Fabrication of a novel cellulose acetate imprinted membrane assisted with chitosan‐wrapped multi‐walled carbon nanotubes for selective separation of salicylic acid from industrial wastewater

Highly selective cellulose acetate (CA) blend imprinted membranes for salicylic acid (SA) removal were synthesized by phase inversion technique with chitosan as a functional polymer and chitosan‐wrapped multi‐walled carbon nanotubes (CHI‐wrapped MWCNTs) as the additives. The surface and cross‐sectional morphology of membranes were strongly affected by the amount of CHI‐wrapped MWCNTs. As compared to M₁‐MIM, M₂‐MIM, and M₄‐MIM, the M₃‐MIM with 2.0 wt % CHI‐wrapped MWCNTs showed higher membrane flux, faster kinetic, binding capacity and better selectivity for SA. The experimental data of adsorption kinetic were well fitted to the pseudo‐second‐order kinetic model by multiple regression analysis. The M₃‐MIM had the maximum adsorption capacity for SA. The selectivity coefficients of SA to p‐hydroxybenzoic acid (p‐HB) and acetylsalicylic acid (ASA) over M₃‐MIM were 6.3090 and 6.0019, respectively, showing that M₃‐MIM had excellent binding affinity and selectivity for separation of SA from SA‐contained aqueous solution. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42654.     

Diffusion with simultaneous reaction of reactive dyes in cellulose. II. Effect of hydrolysis

Theoretical equations that describe the concentration profiles of immobilized and active species for reactive dyes were derived from the diffusion equation accompanied by the reaction with cellulose and water in the substrate. The diffusion coefficient D and the rate constant of the reaction with cellulose, k_cell, and that with water in cellulose, k_w, were estimated by using the theoretical equations and the cylindrical film roll method. The theory predicted that the apparent diffusion coefficients decreased with the hydrolysis of active species in cellulose. Results from diffusion experiments with C.I. Reactive Yellow 4 and Orange 1 show that the ratio P of k_w to k_cell for Orange 1 increased with increase in pH to about pH 13 and that the P for Yellow 4 was smaller than unity. Using an alternative experiment to diffusion, P of Orange 1 was measured to be 1.0–1.5, and that of Yellow 4 was smaller than unity at pH 11.6 at 30°C. It was therefore concluded that the D of active species was constant to a highly alkaline region and that the decrease in the apparent diffusion coefficient of Orange 1 was mainly due to the hydrolysis of active species in cellulose.     

Immobilization of invertase onto crosslinked poly(p‐chloromethylstyrene) beads

Invertase was immobilized onto poly(p‐chloromethylstyrene) (PCMS) beads that were produced by a suspension polymerization with an average size of 186 μm. The beads had a nonporous but reasonably rough surface. Because of this, a reasonably large external surface area (i.e., 14.1 m²/g) could be achieved with the proposed carrier. A two‐step functionalization protocol was followed for the covalent attachment of invertase onto the bead surface. For this purpose, a polymeric ligand that carried amine groups, polyethylenimine (PEI), was covalently attached onto the bead surface by a direct chemical reaction. Next, the free amine groups of PEI were activated by glutaraldehyde. Invertase was covalently attached onto the bead surface via the direct chemical reaction between aldehyde and amine groups. The appropriate enzyme binding conditions and the batch‐reactor performance of the immobilized enzyme system were investigated. Under optimum immobilization conditions, 19 mg of invertase was immobilized onto each gram of beads with 80% retained activity after immobilization. The effects of pH and temperature on the immobilized invertase activity were determined and compared with the free enzyme. The kinetic parameters K_M and V_M were determined with the Michealis–Menten model. K_M of immobilized invertase was 1.75 folds higher than that of the free invertase. The immobilization caused a significant improvement in the thermal stability of invertase, especially in the range of 55–65°C. No significant internal diffusion limitation was detected in the immobilized enzyme system, probably due to the surface morphology of the selected carrier. This result was confirmed by the determination of the activation energies of both free and immobilized invertases. The activity half‐life of the immobilized invertase was approximately 5 times longer than that of the free enzyme. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1268–1279, 2002     

Molecular Weight Polydispersity Effects on Diffusion at Polymer/Polymer Interfaces

The effect of molecular weight distribution (MWD) on diffusion at symmetric polymer/polymer interfaces is investigated by rheological tools. A new model allowing the determination of a self‐diffusion coefficient of polydisperse polymer systems is presented. The model is based on the double reptation theory and Doi and Edwards' molecular dynamics applied to A/A polymers brought into intimate contact in the molten state. The material parameters for the model are obtained from linear oscillatory shear experiments, in which the dynamic shear modulus is measured in parallel plate geometry under a small amplitude of deformation as a function of time and frequency for a sandwich‐like assembly. The experiments were conducted on polystyrene (PS) blends with constant weight average molecular weight (M_w) but with variable number average molecular weights (M_n). The measured self‐diffusion coefficients showed that the presence of short molecules in the blend increases the mean value of the self‐diffusion coefficient and the magnitude of such increase can be quantitatively evaluated by the proposed model.     

Batch foaming of carboxylated multiwalled carbon nanotube/poly(ether imide) nanocomposites: The influence of the carbon nanotube aspect ratio on the cellular morphology

A series of microcellular poly(ether imide) (PEI) foams and nanocellular carboxylated multiwalled carbon nanotube (MWCNT‐COOH)/PEI foams were prepared by the batch foaming method. MWCNT‐COOHs with different aspect ratios were introduced into the PEI matrix as heterogeneous nucleation agents to improve the cell morphology of the microcellular PEI foams. The effect of the aspect ratio of the MWCNT‐COOHs on the cellular morphology, and gas diffusion is discussed. The results show that with the addition of MWCNT‐COOH, the sorption curve showed a slight reduction of carbon dioxide solubility, but the gas diffusion rate could be improved. The proper aspect ratio of MWCNT‐COOH could improve the cellular morphology under the same foaming conditions, in which m‐MWCNT‐COOH (aspect ratio ≈ 1333) was the best heterogeneous nucleation agent. When the foaming temperature was 170°C, the cell size and cell density of nanocellular m‐MWCNT‐COOH reduced to 180 nm and increased to 1.58 × 10¹³ cells/cm³, respectively. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42325.