Biphasic Morphology Research Articles

Poly(Lactic Acid)-Based Blends With Tailored Physicochemical Properties for Tissue Engineering Applications: A Case Study

Binary blends of poly(L-lactic) acid (PLLA: 201790 Da) and poly(lactide-co-glycolide) (PLGA) (LA:GA = 50:50 mol:mol; 32030 Da) with various compositions were prepared. Physicochemical properties of PLLA/PLGA blends were analyzed. Blends showed a biphasic morphology, with distinct glass transition temperatures, which only slightly approximated compared to pure polymers. Analysis of tensile mechanical properties through the Kerner-Uemura-Takayanagi model showed compatibility for PLLA/PLGA 75/25 blend. Rapid degradation of PLGA phase (2–8 weeks) in PLLA/PLGA 75/25 blend led to porous samples, which appear promising for drug delivery and tissue engineering. A limited inflammatory reaction resulted from subcutaneous implantation of PLLA/PLGA 75/25 in Balb-c mice.

Viscoelastic behaviour of asphalt modified by grafted tri-block copolymers: predictions of fractional rheological models

Blends of asphalt with three maleic anhydride-modified triblock copolymers are prepared and analysed in detail for potential use in pavement construction. These blends are compared with those made with the copolymers without chemical modification. The use of grafted polymers improves the conventional properties of blends made with the asphalt and precursor polymers, such as penetration, softening point, storage stability at high temperature and the rheological properties. In addition, blends made with the chemically modified polymers present biphasic morphology with improved dispersion and interconnected phases. Semi-empirical models corresponding to a constitutive equation with fractional derivatives are proposed to predict the linear viscoelastic properties of the blends using few parameters for each temperature. The fractional Kelvin, fractional standard linear solid and fractional Maxwell models are shown to predict appropriately the linear viscoelastic properties from 25 to 75°C at frequencies from 0.1 to 100 rad/s.

Comparative study on tensile properties and microstructure development in elastomer‐modified cyclic olefin copolymer

Mechanical and morphological properties of blends of cyclic olefin copolymer (COC) with polyolefin‐octane copolymer (POE) and polyethylene‐vinyl acetate (EVA), as the second phase, are thoroughly discussed over full composition range. Scanning electron microscopy revealed that both the systems are immiscible pairs showing biphasic morphology; however, co‐continuity was seen upon varying composition. The mechanical characteristics, tensile modulus, yield strength, tensile strength, and elongation at break were evaluated varying blend composition. It was found that addition of POE to COC results in a higher decrease in tensile modulus when compared to COC/EVA pair. Mechanical results were correlated with several theoretical models and the best model for estimating tensile modulus was determined. Among examined models, the best fitting to experimental data for both series of the blends was provided by the Lyngaae‐Jorgensen model. J. VINYL ADDIT. TECHNOL., 22:222–230, 2016. © 2014 Society of Plastics Engineers

Advanced Interatrial Block is Associated with Recurrence of Atrial Fibrillation Post Pharmacological Cardioversion

Management of atrial fibrillation (AF) is hampered by frequent recurrences after restoration of sinus rhythm. Delayed interatrial conduction has been associated with the development of AF in different clinical settings. The aim of our study was to assess whether advanced interatrial block (aIAB) was associated with AF recurrence after pharmacological cardioversion with two different antiarrhythmic drugs. We included 61 patients with recent onset AF without structural heart disease that underwent successful pharmacological cardioversion. Thirty-one patients received a single oral dose of propafenone, and 30 patients received iv vernakalant. A 12-lead ECG (filter 150Hz, 25mm/s, 10mm/mV) after conversion was evaluated for the presence of interatrial block (IAB); partial (pIAB): P-wave duration>120ms, and advanced (aIAB): P-wave>120ms and biphasic morphology (±) in inferior leads. Clinical follow-up and electrocardiographic recordings were performed for a 12-month period. Age was 58±10.4years and 50.8% were male. aIAB was present in 11 patients (18%) and pIAB in 10 (16.4%). At 1-year follow-up, 22 patients (36%) had AF recurrence. The recurrence rate with aIAB was 90.9% versus 70% in those with pIAB and 12.5% in normal P-wave duration (P=0.001). The presence of aIAB was strongly associated with AF recurrence (odds ratio 18.4 in multivariable modeling). Recurrence was not affected by the drug used for cardioversion (P=0.92). Advanced interatrial block is associated with higher risk of AF recurrence at 1year after pharmacological cardioversion, independent of the drug used.

Relation of Interatrial Block to New-Onset Atrial Fibrillation in Patients With Chagas Cardiomyopathy and Implantable Cardioverter-Defibrillators

Chagas cardiomyopathy is an endemic disease in Latin America. A significant proportion of patients develop atrial fibrillation (AF), which may result in stroke and increased morbidity or mortality. Interatrial block (IAB) has been associated with the development of AF in different clinical scenarios. The aim of our study was to determine whether IAB can predict new-onset AF in patients with Chagas cardiomyopathy and implantable cardioverter-defibrillators (ICDs). We conducted a retrospective study of patients with Chagas cardiomyopathy and ICDs from 14 centers in Latin America. Demographics, clinical, and device follow-up were collected. Surface electrocardiograms were scanned at 300 dpi and maximized ×8. Semiautomatic calipers were used to determine P-wave onset and offset. Partial IAB was defined as a P wave of >120 ms and advanced IAB as a P wave of >120 ms with biphasic morphology (±) in inferior leads. AF events and ICD therapies were reviewed during follow-up by 2 independent investigators. A total of 80 patients were analyzed. Mean age was 54.6 ± 10.4 years, and 52 (65%) were male. Mean left ventricular ejection fraction was 40 ± 12%. IAB was detected in 15 patients (18.8%), with 8 (10.0%) partial and 7 (8.8%) advanced. During a follow-up of 33 ± 20 months, 11 patients (13.8%) presented with new AF. IAB (partial + advanced) was strongly associated with new AF (p <0.0001) and inappropriate therapy by the ICD (p = 0.014). In conclusion, IAB (partial + advanced) predicted new-onset AF in patients with Chagas cardiomyopathy and ICDs.

Effects of organoclay on the compatibility and interfacial phenomena of PE/EVA blends with UCST phase behavior

The compatibilization effects of organically modified nanoclay on the miscibility window, phase separation kinetics, biphasic morphology, interfacial tension, and final properties of polyethylene/ethylene vinyl acetate copolymer blends exhibiting UCST behavior have been investigated. Regardless of blend composition, intercalated nanoclay decreases the phase transition temperatures to lower values and changes the symmetry of phase diagram. The miscibility of PE and EVA phases in the amorphous regions of nanocomposites noticeably enhances and finer biphasic morphology is obtained by the incorporation of organoclay. The pinning influence of the nanofiller on polymer chain diffusion causes much slower phase separation kinetics for the nanocomposites. Similar to conventional compatibilizers such as block copolymers, the interfacial activity of nanoclay leads to a sharp decline in the interfacial tension of PE/EVA up to 2‐orders of magnitude. Moreover, the results show that imposing restrictions on the phase separation phenomenon increases the impact strength of the virgin blend and related nanocomposite. However, this improvement has been much more noticeable in the presence of nanoparticles, which is due to the simultaneous roles of organoclay as an effective compatibilizer and reinforcement. POLYM. COMPOS., 35:2329–2342, 2014. © 2014 Society of Plastics Engineers

Intracranial gliofibroma: a case report and review of the literature.

Gliofibroma is a rare tumor with biphasic morphology, commonly occurring in the first two decades of life. Currently, the tumor is not listed as a distinct entity in the current World Health Organization (WHO) classification of central nervous system tumors. As its biological behavior, histogenesis, and prognostic factors are still debated, the aim of this paper was to describe a case of a gliofibroma and to update the data about these lesions. Hence, we present here clinical symptoms, pathological findings, and evolution observed in a child with gliofibroma. A 10-year-old girl with seizures was referred for study. Neuroimaging showed a hemispheric hyperdense tumor with little peritumoral edema and no mass effect. The tumor was totally removed. Histologically, the tumor consisted of a mixture of glial cells and collagen-rich stroma. Immunohistochemical examination revealed positive staining for GFAP, CD 99, S100, and vimentin. EMA staining showed a paranuclear dot pattern in only few cells in isolated areas. These findings of a glial component with collagenous stroma were consistent with a desmoplastic glioma. Because of the rarity of this entity, we believe it is important to report every case in order to adequately analyze and categorize the tumor in the next WHO classification.

Cytokeratin expression in gastrointestinal stromal tumors: morphology, meaning, and mimicry.

Gastrointestinal stromal tumors (GISTs) are biologically distinctive neoplasms harboring KIT and PDGFRA mutations. Cytokeratin expression in GISTs is an under-recognized diagnostic pitfall, especially in high grade GISTs with limited biopsy material and from metastatic sites. We evaluated the histomorphology and expression of four 'broad-spectrum' cytokeratin markers, AE1-AE3, CAM 5.2, MNF-116, and 34βE12 in 64 GISTs diagnosed over a 68-month period. Individual cytokeratins 5, 6, 7, 8, 14, 17, 18, 19, and 20 were investigated in the 'broad-spectrum' cytokeratin-positive GISTs. Of 64 GISTs, 10 (15%) demonstrated cytokeratin immunopositivity. All 10, considered high risk by the National Institutes of Health consensus approach, were immunopositive for CAM 5.2 and MNF-116. Seven were AE1-AE3 immunopositive. Cytokeratins 8 and 18 were confirmed in 10 and 9 GISTs, respectively. One GIST demonstrated biphasic morphology with cytokeratin immunonegativity in low-grade spindle and immunopositivity in high-grade epithelioid foci. KIT and PDGFRA mutational analysis, undertaken in 5/10 cytokeratin-positive GISTs, harbored KIT exon 11 mutations. We hypothesize that cytokeratin expression exclusively in high risk GISTs is a consequence of tumor progression. Given the increasing number of commercially available broad-spectrum cytokeratin immunomarkers, including those reacting with cytokeratins 8 and 18, cytokeratin-positive GISTs must be differentiated from carcinomas, melanomas, and a range of cytokeratin-positive sarcomas to ensure optimal patient management and prognostication.

Star Polymer Unimicelles on Graphene Oxide Flakes

We report the interfacial assembly of amphiphilic heteroarm star copolymers (PSnP2VPn and PSn(P2VP-b-PtBA)n (n = 28 arms)) on graphene oxide flakes at the air-water interface. Adsorption, spreading, and ordering of star polymer micelles on the surface of the basal plane and edge of monolayer graphene oxide sheets were investigated on a Langmuir trough. This interface-mediated assembly resulted in micelle-decorated graphene oxide sheets with uniform spacing and organized morphology. We found that the surface activity of solvated graphene oxide sheets enables star polymer surfactants to subsequently adsorb on the presuspended graphene oxide sheets, thereby producing a bilayer complex. The positively charged heterocyclic pyridine-containing star polymers exhibited strong affinity onto the basal plane and edge of graphene oxide, leading to a well-organized and long-range ordered discrete micelle assembly. The preferred binding can be related to the increased conformational entropy due to the reduction of interarm repulsion. The extent of coverage was tuned by controlling assembly parameters such as concentration and solvent polarity. The polymer micelles on the basal plane remained incompressible under lateral compression in contrast to ones on the water surface due to strongly repulsive confined arms on the polar surface of graphene oxide and a preventive barrier in the form of the sheet edges. The densely packed biphasic tile-like morphology was evident, suggesting the high interfacial stability and mechanically stiff nature of graphene oxide sheets decorated with star polymer micelles. This noncovalent assembly represents a facile route for the control and fabrication of graphene oxide-inclusive ultrathin hybrid films applicable for layered nanocomposites.

Pulmonary blastoma: A clinicopathologic study of three cases.

e19140 Background: Pulmonary blastoma (PB) is a rare biphasic neoplasm representing 0.2-0.5% of pulmonary malignancies. Presentation ranges from asymptomatic to symptoms of advanced pulmonary tumors. Surgery is the preferred treatment with no consensus on the role of other adjuvant therapies. Methods: We report the clinicopathologic features of PB in 3 patients (pts). Retrospective review of medical records of pts diagnosed with PB at Jackson Memorial Hospital, Miami, FL since 2009. Staging performed using the 2009 AJCC system for NSCLC. Cases required pathological diagnosis before inclusion. Variables analyzed were demographics, clinicopathologic presentation, treatments and outcomes. Results: Mean age at diagnosis was 53 years old; 2 were male; Hispanic and Caucasian and 1 African American female. Both males were heavy smokers. At diagnosis, all cases were symptomatic; 1 had hypercalcemia of 12.9 mg/dL and 2 were stage IV with metastatic disease (bone and thyroid). 2/3 where treated with surgical resection and both achieved complete remission (CR); Pt with stage IV and resection relapsed in 28 months, received chemotherapy (3 cycles cisplatin/docetaxel) with progressive disease then radiation (37 Gy) without response and died. The other surgical patient remains in CR. The patient with unresectable disease received chemotherapy (6 cycles carboplatin/docetaxel) attaining partial remission. 2/3 patients remain alive at end of this study. Pathologically, all cases showed biphasic morphology composed of multiple glandular structures with atypical pseudostratified columnar epithelium and cellular stromal component. Immunohistochemical analysis revealed positivity in all cases for thyroid transcription factor (TTF-1), keratin, and epithelial membrane antigen (EMA) in the glandular component. Conclusions: All pts were symptomatic at diagnosis and 2 presented with metastatic disease. All pts had similar morphologically and immunophenotypically. Surgery was the most beneficial intervention in regard to CR and PFS. Chemotherapy has shown mixed responses, thus, larger studies are needed to define the role of chemotherapy in the adjuvant and palliative settings.

Pulmonary Function and Flow-Volume Loop Patterns in Patients with Tracheobronchomalacia

Patterns of pulmonary function tests (PFTs) and flow-volume loops among patients with clinically important tracheobronchomalacia (TBM) are not well described. Small studies suggest 4 main flow-volume loop morphologies: low maximum forced expiratory flow, biphasic expiratory curve, flow oscillations, and notching. We studied common PFT and flow-volume loop patterns among the largest prospective series of patients to date, undergoing clinical evaluation for symptomatic moderate to severe TBM. We conducted a retrospective analysis of prospectively collected data from patients who were referred to our Chest Disease Center from January 2002 to December 2008, with respiratory symptoms that were attributed primarily to TBM. The PFT results of 90 subjects with symptomatic moderate to severe TBM were evaluated. By PFTs, 40 (44.4%) subjects had an obstructive ventilatory defect, 16 (17.8%) had a definite or highly likely restrictive ventilatory defect, 15 (16.7%) had a mixed defect, and 19 (21.1%) were within normal limits. Among 76 subjects with available flow-volume loops, the most frequent finding was low maximum forced expiratory flow, in 62 (81.6%) subjects, followed by biphasic morphology (15, 19.7%), notched expiratory loop (7, 9.2%), and expiratory oscillations (2, 2.6%). The balance of 13 subjects (17.1%) had no distinctive flow-volume loop abnormality. PFTs and flow-volume loops are normal in a substantial number of patients with moderate to severe TBM, and should not be used to decide whether TBM is present or clinically important.

A Microblock Ionomer in Proton Exchange Membrane Electrolysis for the Production of High Purity Hydrogen

Proton exchange membranes (PEM’s) are currently under investigation for membrane water electrolysis (PEMWE) to deliver efficient production of the high purity hydrogen needed to supply emerging clean-energy technologies such as hydrogen fuel cells. The microblock aromatic ionomer described in this work achieves high mechanical strength in an aqueous environment as a result of its designed, biphasic morphology and displays many of the qualities required in a PEM. The new ionomer membrane thus shows good proton conductivity (63 mS cm–1 at 80 °C and 100% RH), while retaining mechanical integrity under high temperature, hydrated conditions. Testing in electrolysis has shown good energy efficiency (1.67 V at 1 A cm–2 and 80 °C, corresponding to 4 kWh/Nm3 of H2), making this ionomer a potential candidate for commercial application in PEMWE.

Phase behavior of UCST blends: Effects of pristine nanoclay as an effective or ineffective compatibilizer

The effects of unmodified nanoclay (natural montmorillonite) on the miscibility, phase behavior and phase sepa- ration kinetics of polyethylene (PE)/ethylene vinyl acetate copolymer (EVA) blends have been investigated. Depending on the blend composition, it was observed that the intercalated pristine nanoclay influences the biphasic morphology either as an effective compatibilizer or just as an ineffectual modifier. In spite of the presence of micrometer-sized agglomerated tac- toids, natural nanoclay can play a thermodynamic role in reducing the interfacial tension of polymer components. The addi- tion of clay nanoparticles was found to change the phase diagram slightly and diminishes the composition dependency of the binodal temperatures. Moreover, it was observed that a small amount of unmodified layered silicate slows down the phase separation process considerably and enhances the solubility of each polymer in the domains of its counterpart. The findings of this study verify that even poorly dispersed nanoclay with high surface tension can act as a conventional com- patibilizer and change the immiscible PE/EVA blends to the partially miscible ones.

Cell–material interactions on biphasic polyurethane matrix

Cell-matrix interaction is a key regulator for controlling stem cell fate in regenerative tissue engineering. These interactions are induced and controlled by the nanoscale features of extracellular matrix and are mimicked on synthetic matrices to control cell structure and functions. Recent studies have shown that nanostructured matrices can modulate stem cell behavior and exert specific role in tissue regeneration. In this study, we have demonstrated that nanostructured phase morphology of synthetic matrix can control adhesion, proliferation, organization and migration of human mesenchymal stem cells (MSCs). Nanostructured biodegradable polyurethanes (PU) with segmental composition exhibit biphasic morphology at nanoscale dimensions and can control cellular features of MSCs. Biodegradable PU with polyester soft segment and hard segment composed of aliphatic diisocyanates and dipeptide chain extender were designed to examine the effect polyurethane phase morphology. By altering the polyurethane composition, morphological architecture of PU was modulated and its effect was examined on MSC. Results show that MSCs can sense the nanoscale morphology of biphasic polyurethane matrix to exhibit distinct cellular features and, thus, signifies the relevance of matrix phase morphology. The role of nanostructured phases of a synthetic matrix in controlling cell-matrix interaction provides important insights for regulation of cell behavior on synthetic matrix and, therefore, is an important tool for engineering tissue regeneration.

Molecular Confirmation of t(6;11)(p21;q12) Renal Cell Carcinoma in Archival Paraffin-embedded Material Using a Break-apart TFEB FISH Assay Expands its Clinicopathologic Spectrum

A subset of renal cell carcinomas (RCCs) is characterized by t(6;11)(p21;q12), which results in fusion of the untranslated Alpha (MALAT1) gene to the TFEB gene. Only 21 genetically confirmed cases of t(6;11) RCCs have been reported. This neoplasm typically demonstrates a distinctive biphasic morphology, comprising larger epithelioid cells and smaller cells clustered around basement membrane material; however, the full spectrum of its morphologic appearances is not known. The t(6;11) RCCs differ from most conventional RCCs in that they consistently express melanocytic immunohistochemical (IHC) markers such as HMB45 and Melan A and the cysteine protease cathepsin K but are often negative for epithelial markers such as cytokeratins. TFEB IHC has been proven to be useful to confirm the diagnosis of t(6;11) RCCs in archival material, because native TFEB is upregulated through promoter substitution by the gene fusion. However, IHC is highly fixation dependent and has been proven to be particularly difficult for TFEB. A validated fluorescence in situ hybridization (FISH) assay for molecular confirmation of the t(6;11) RCC in archival formalin-fixed, paraffin-embedded material has not been previously reported. We report herein the development of a break-apart TFEB FISH assay for the diagnosis of t(6;11)(p21;q12) RCCs. We validated the assay on 4 genetically confirmed cases and 76 relevant expected negative control cases and used the assay to report 8 new cases that expand the clinicopathologic spectrum of t(6;11) RCCs. An additional previously reported TFEB IHC-positive case was confirmed by TFEB FISH in 46-year-old archival material. In conclusion, TFEB FISH is a robust, clinically validated assay that can confirm the diagnosis of t(6;11) RCC in archival material and should allow a more comprehensive clinicopathologic delineation of this recently recognized neoplastic entity.

Papillary glioneuronal tumor—a rare entity: report of four cases and brief review of literature

Papillary glioneuronal tumors (PGNT) have been recently included as a distinct entity in the WHO classification of tumors of the central nervous system. Their molecular pathogenesis is not clear. In the current study, we present the morphological, immunohistochemical, and molecular features of four cases of PGNT reported over the past 11 years. Over a period of 11 years (January 2000-February 2010), there were four cases of PGNT, which were reviewed for histomorphological features. TP53 and IDH1 mutations were assessed using antibodies against p53 protein and for mutant IDH1(R132H) protein, respectively. Immunohistochemistry was also performed for epidermal growth factor receptor (EGFR) protein. Fluorescence in situ hybridization assay was used for analyzing 1p/19q deletion status. All the tumors showed the characteristic biphasic morphology. Rare findings included minigemistocyte-like cells in one, angiomatous areas in three, focal necrosis in one, and a high MIB-1 labeling index of 12 and 13 %, respectively, in two of the cases. All lacked EGFR, IDH1 expression, and 1p/19q deletions. Interestingly, antibody for p53 labeled the tumor cells, mainly those showing glial differentiation, in two cases. At a mean follow-up of 30 months, there was no evidence of disease progression except in one case which recurred after 24 months. PGNT are rare CNS neoplasms. Despite showing focal morphological features reminiscent of oligodendroglial tumors and presence of astrocytic component, they usually lack the common genetic alterations involved in the pathogenesis of gliomas. Multi-institutional pooling of cases may aid in elucidating their oncogenetic pathway.

Thermoplastic polyurethanes with polycarbonate soft phase: Effect of thermal treatment on phase morphology

The thermal sensitivity of thermoplastic polyurethanes with polycarbonate soft phase (PCU) is considered. Thermal treatments were coupled with differential scanning calorimetry and infrared spectroscopy to investigate the effect of temperature on the phase morphology. PCU is characterized by a biphasic morphology: ordered hard polyurethane micro-domains are dispersed in a soft phase matrix, containing both hard and soft segments. Heating may completely destroy the short and long range order or simply change it. The infrared behaviour of the CO and NH stretching regions gives information on the organization of the segments. Thermal treatments above the processing temperature lead to an unstable monophasic morphology, that at room temperature is subjected to segregation of the hard segments, in order to recreate the biphasic morphology. Annealing treatments below the processing temperature cause reorganization in the hard micro-domains, inducing changes in their amount and dimensions. The result of the annealing depends on the temperature and on the exposure time. The thermal sensitivity also involves the chemical properties, given the thermal lability of the urethane bonds in the range of the processing temperature.

Chromosomal imbalances in primary hepatic carcinosarcoma

Hepatic carcinosarcoma is an infrequent biphasic tumor composed of carcinomatous and sarcomatous elements, harboring an unfavorable prognosis. The developmental origin of both tumor components and possible molecular genetic mechanisms involved in tumorigenesis are still unclear. We report here a case of hepatic carcinosarcoma in a 76-year-old patient. The tumor was surgically resected and examined histopathologically including immunohistochemical staining. Focal hepatocellular differentiation was detected in the carcinomatous components but also in the pleomorphic undifferentiated spindle cells. Comparative genomic hybridization revealed amp 1q, -4q, -5p14pter, -5q13q31, +6p, -6q, -8p12pter, -12p, -13q12q14, -14q in the carcinomatous components, and +6p, -10q25qter, -22q in the sarcomatous components. The common +6p harbors the serum response factor gene encoding a transcription factor involved in cell proliferation, migration, and differentiation, confirmed by immunostaining. Hepatic carcinosarcoma is a tumor with biphasic morphology but possible monoclonal origin, showing advanced tumor progression in the carcinomatous areas.

Compatibilization Efficacy of LLDPE-g-MA on Mechanical, Thermal, Morphological and Water Absorption Properties of Nylon-6/LLDPE Blends

The effect of compatibilizer (LLDPE-g-MA) on mechanical, thermal, morphological and water absorption properties of Nylon-6/LLDPE blends was investigated. SEM analysis and image processing revealed coarse biphasic morphology with LLDPE dispersant size in the range of 1.97–2.23 µm for uncompatibilized blends wherein compatibilized blends showed smooth morphology with dispersant size in the range of 0.76–1.34 µm. Compatibilization effect has also been supplemented by thermal studies showing shift in crystalline melting point of Nylon-6 in compatibilized blends reflecting improved interfacial interaction. Compatibilized blends showed 10–25% overall improvement in mechanical properties and 15–35% reduction in water absorption as compared to uncompatibilized blends.

Morphological structure and surface properties of maleated ethylene propylene diene monomer/organoclay nanocomposites

AbstractThe phase morphology and surface properties of some maleated ethylene propylene‐diene/organoclay nanocomposites (EPDM‐g‐MA/OC) were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle measurements. The effect of organoclay and/or compatibilizing agent [maleic anhydride‐grafted polypropylene (PP‐g‐MA)] on the properties of the EPDM‐g‐MA nanocomposites was investigated. The quality and uniformity of nanoclay dispersion were analyzed by SEM and AFM images. The experimental results showed an intercalate structure and biphasic morphology for the binary blends based on EPDM and clay. The surface properties of the studied composites are significantly influenced by the presence of a compatibilizing agent—PP‐g‐MA. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers