Simulation of Structural Characteristics and Depth Filtration Elements in Interconnected Nanofibrous Membrane Based on Adaptive Image Analysis

Mohammad Kazemi Pilehrood, Pirjo Heikkilä, Ali Harlin

VTT Technical Research Centre of Finland, Espoo, Finland.

DOI: 10.4236/wjnse.2013.31002                

Abstract

Due to their unique structural features, electrospun membranes have gained considerable attention for use in applications where quality of depth filtration is a dominant performance factor. To elucidate the depth filtration phenomena it is important to quantify the intrinsic structural properties independent from the dynamics of transport media. Several methods have been proposed for structural characterization of such membranes. However, these methods do not meet the requirement for the quantification of intrinsic structural properties in depth filtration. This may be due to the complex influence of transport media dynamics and structural elements in the depth filtration process. In addition, the different morphological architectures of electrospun membranes present obstacles to precise quantification. This paper seeks to quantify the structural characteristics of electrospun membranes by introducing a robust image analysis technique and exploiting it to evaluate the permeation-filtration mechanism. To this end, a nanostructured fibrous network was simulated as an ideal membrane using adaptive local criteria in the image analysis. The reliability of the proposed approach was validated with measurements and comparison of structural characteristics in different morphological conditions. The results were found to be well compatible with empirical observations of perfect membrane structures. This approach, based on optimization of electrospinning parameters, may pave the way for producing optimal membrane structures for boosting the performance of electrospun membranes in end-use applications.

Keywords

Nanofibrous Membrane; Image Analysis; Local Criteria; Structural Characteristics; Pore Interconnectivity; Depth Filtration

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	P. Heikkil?, “Nanostructured Fiber Composites, and Materials for Air Filtration,” Ph.D. Dissertation, Tampere University of Technology, Tampere, 2008.
[2]	P. Gibson, H. S. Gibson and D. Rivin, “Transport Properties of Porous Membranes Based on Electrospun Nanofibers,” Colloids and Surfaces, Vol. 187-188, 2001, pp. 469-481. doi:10.1016/S0927-7757(01)00616-1
[3]	R. Gopal, S. Kaur, Z. Ma, C. Chan, S. Ramakrishna and T. Matsuur, “Electrospun Nanofibrous Filtration Membrane,” Journal of Membrane Science, Vol. 281, No. 1-2, 2006, pp. 581-586. doi:10.1016/j.memsci.2006.04.026
[4]	C. S. Ki, E. H. Gang, I. C. Um and Y. H. Park, “Nanofibrous Membrane of Wool Keratose/Silk Fibroin Blend for Heavy Metal Ion Adsorption,” Journal of Membrane Science, Vol. 302, No. 1, 2007, pp. 20-26. doi:10.1016/j.memsci.2007.06.003
[5]	S. Zhang, W. S. Shim and J. Kim, “Design of Ultra-Fine Nonwovens via Electrospinning of Nylon 6: Spinning Parameters and Filtration Efficiency,” Materials and Design, Vol. 30, No. 9, 2009, pp. 3659-3666. doi:10.1016/j.matdes.2009.02.017
[6]	R. S. Barhate and S. Ramakrishna, “Nanofibrous Filtering Media: Filtration Problems and Solutions from Tiny Materials,” Journal of Membrane Science, Vol. 296, No.1-2, 2007, pp. 1-8. doi: 10.1016/j.memsci.2007.03.038
[7]	C. Feng, K. C. Khulbe and T. Matsuura, “Recent Progress in the Preparation, Characterization, and Applications of Nanofibers and Nanofiber Membranes via Electrospinning/Interfacial Polymerization,” Journal of Applied Polymer Science, Vol. 115, No. 2, 2010, pp. 756-776. doi:10.1002/app.31059
[8]	J. Hr?za and J. Poláchová, “Respirator Filters with Nanofibers,” Proceedings of AUTEX Conference University of Maribor, Portoroz Slovenia, 2005, pp. 149-154.
[9]	K. Graham, M. Ouyang, T. Raether, T. Grafe, B. McDonald and P. Knauf, “Polymeric Nanofibers in Air Filtration Applications,” Proceedings of the Fifteenth Annual Technical Conference & Expo of the American Filtration & Separations Society, Texas, 9-12 April 2002.
[10]	T. Grafe, M. Gogins, M. Barris, J. Schaefer and R. Canepa, “Nanofibers in Filtration Applications in Transportation,” Proceedings of the Filtration 2001 International Conference and Exposition of the INDA (Association of the Nonwovens Fabric Industry), 3-5 December 2001.
[11]	S. W. Choi, S. M. Jo, W. S. Lee and Y. R. Kim, “An Electrospun Poly(vinylidene fluoride) Nanofibrous Membrane and Its Battery Applications,” Advanced Materials, Vol. 15, No. 23, 2003, pp. 2027-2032. doi:10.1002/adma.200304617
[12]	A. L. Gopalan, P. Santhosh, K. M. Manesh, J. H. Nho, S. H. Kim, C. G. Hwang and K. P. Lee, “Development of Electrospun PVdF-PAN Membrane-Based Polymer Electrolytes for Lithium Batteries,” Journal of Membrane Science, Vol. 325, No. 2, 2008, pp. 683-690. doi:10.1016/j.memsci.2008.08.047
[13]	H. Yoshimoto, Y. M. Shin, H. Terai and J. P. Vacanti, “A Biodegradable Nanofiber Scaffold by Electrospinning and Its Potential for Bone Tissue Engineering,” Biomaterials, Vol. 24, No. 12, 2003, pp. 2077-2083. doi:10.1016/S0142-9612(02)00635-X
[14]	S. R. Bhattarai, N. Bhattarai, H. K. Yi, P. H. Hwang, D. I. Cha, H. Y. Kim, “Novel Biodegradable Electrospun Membrane: Scaffold for Tissue Engineering,” Biomaterials, Vol. 25, 2004, pp. 2595-2602. doi:10.1016/j.biomaterials.2003.09.043
[15]	T. Tamura and H. Kawakami, “Aligned Electrospun Nanofiber Composite Membranes for Fuel Cell Electrolytes,” Nano Letter, Vol. 10, No. 4, 2010, pp. 1324-1328. doi:10.1021/nl1007079
[16]	B. Dong, L. Gwee, D. S. L. Cruz, K. I. Winey and Y. A. Elabd, “Super Proton Conductive High-Purity Nafion Nanofibers,” Nano Letter, Vol. 10, No. 9, 2010, pp. 3785-3790. doi:10.1021/nl102581w
[17]	A. H. Tehrani, A. Zadhoush, S. Karbasi and H. S. Aliabadi, “Scaffold Percolative Efficiency: In Vitro Evaluation of the Structural Criterion for Electrospun Mats,” Journal of Materials Science: Materials in Medicine, Vol. 21, No.11, 2010, pp. 2989-2998. doi:10.1007/s10856-010-4149-7
[18]	S. A. Hosseini and H. V. Tafreshi, “Modeling Permeability of 3-D Nanofiber Media in Slip Flow Regime,” Chemical Engineering and Science, Vol. 65, No. 6, 2010, pp. 2249-2254. doi:10.1016/j.ces.2009.12.002
[19]	S. A Hosseini and H. V. Tafreshi, “3-D Simulation of Particle Filtration in Electrospun Nanofibrous Filters,” Powder Technology, Vol. 201, No. 2, 2010, pp. 153-160. doi:10.1016/j.powtec.2010.03.020
[20]	W. Sambaera, M. Zatloukal and D. Kimmer, “3D Modeling of Filtration Process via Polyurethane Nanofiber Based Nonwoven Filters Prepared by Electrospinning Process,” Chemical Engineering Science, Vol. 66, No. 4, 2011, pp. 613-623. doi:10.1016/j.ces.2010.10.035
[21]	S. Jaganathan, H. V. Tafreshi and B. Pourdeyhimi, “A Realistic Approach for Modeling Permeability of Fibrous Media: 3-D Imaging Coupled with CFD Simulation,” Chemical Engineering and Science, Vol. 63, No. 1, 2008, pp. 244-252. doi:10.1016/j.ces.2007.09.020
[22]	M. Ziabari, V. Mottaghitalab and A. K. Haghi, “Evaluation of Electrospun Nanofiber Pore Structure Parameters,” Korean Journal of Chemical Engineering, Vol. 25, No. 2, 2008, pp. 923-932. doi:10.1007/s11814-008-0151-x
[23]	L. G. Mobarakeh, D. Semnani and M. Morshed, “A Novel Method for Porosity Measurement of Various Surface Layers of Nanofibers Mat using Image Analysis for Tissue Engineering Applications,” Journal of Applied Polymer Science, Vol. 106, No. 4, 2007, pp. 2536-2542. doi:10.1002/app.26949
[24]	M. Ziabari, V. Mottaghitalab and A. K. Haghi, “A New Image Analysis Based Method for Measuring Electrospun Nanofiber Diameter,” Nanoscale Research Letters, Vol. 2, No. 12, 2007, pp. 597-600. doi:10.1007/s11671-007-9093-1
[25]	M. K. Pilehrood, P. Heikkil? and A. Harlin, “Preparation of Carbon Nanotube Embedded in Polyacrylonitrile (PAN) Nanofibre Composites by Electrospinning Process,” AUTEX Research Journal, Vol. 12, No. 1, 2012, pp. 1-6.
[26]	M. Sezgin and B. Sankur, “Survey over Image Thresholding Techniques and Quantitative Performance Evaluation,” Journal of Electronic Imaging, Vol. 13, No. 1, 2004, pp. 146-168. doi:10.1117/1.1631315
[27]	Z. Chi and K. W. Wong, “A Two-Stage Binarization Approach for Document Images,” Proceedings of 2001 International Symposium on Intelligent Multimedia, Video and Speech Processing, Hong Kong, 2-5 May 2001, pp. 275-278.
[28]	J. R. Parker, “Gray Level Thresholding in Badly Illuminated Images,” IEEE Transaction on Pattern Analysis and Machine Intelligent, Vol. 13, No. 8, 1991, pp. 813-819. doi:10.1109/34.85672
[29]	J. A. Burghardt, G. J. Kazakia and S. Majumdar, “A Local Adaptive Threshold Strategy for High Resolution Peripheral Quantitative Computed Tomography of Trabecular Bone,” Annals of Biomedical Engineering, Vol. 35, No. 10, 2007, pp. 1678-1686. doi:10.1007/s10439-007-9344-4
[30]	W. Bieniecki and S. Grabowski, “Multi-Pass Approach to Adaptive Thresholding Based Image Segmentation,” Proceedings of the 8th International IEEE Conference CADSM 2005, Lviv-Polyana, 2005, pp. 418-423.
[31]	2012. http://fiji.sc/Auto_Local_Threshold
[32]	C. Yan and G. Leedham, “Decompose-Threshold Approach to Handwriting Extraction in Degraded Historical Document Images,” Proceedings of the 9th Int’l Workshop on Frontiers in Handwriting Recognition, 26-29 October 2004, pp. 239-244.
[33]	I. Blayvas, A. Bruckstein and R. Kimmel, “Efficient Computation of Adaptive Threshold Surfaces for Image Binarization,” Pattern Recognition, Vol. 39, No. 1, 2006, pp. 89-101. doi:10.1016/j.patcog.2005.08.011
[34]	J. Sauvola and M. Pietaksinen, “Adaptive Document Image Binarization,” Pattern Recognition, Vol. 33, No. 2, 2000, pp. 225-236. doi:10.1016/S0031-3203(99)00055-2
[35]	L. Safinia, A. Mantalaris and A. Bismarck, “Nondestructive Technique for the Characterization of the Pore Size Distribution of Soft Porous Constructs for Tissue Engineering,” Langmuir, Vol. 22, No. 7, 2006, pp. 3235-3242. doi:10.1021/la051762g
[36]	2012. http://www.nist.gov/lispix/doc/particle-form/morph-param.htm
[37]	2012. http://www.sympatec.org/Science/Characterisation/05_ParticleShape.html
[38]	A. Polesel, G. Ramponi and V. J. Mathew, “Image Enhancement via Adaptive Unsharp Masking,” IEEE Transactions on Image Processing, Vol. 9, No. 3, 2000, pp. 505-510. doi:10.1109/83.826787
[39]	G. Ramponi, N. K. Strobel, S. K. Mitra and T. H. Yu, “Nonlinear Unsharp Masking Methods for Image Contrast Enhancement,” Journal of Electronic Imaging, Vol. 5, No. 3, 1991, pp. 353-366. doi:10.1117/12.242618
[40]	A. Polesel, G. Ramponi and V. J. Mathew, “Adaptive Unsharp Masking for Contrast Enhancement,” Proceedings of International Conference of Image Processing, Santa Barbara, 26-29 October 1997, pp. 267-270.
[41]	P. M. Narendra, “A Separable Median Filter for Image Noise Smoothing,” IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 3, No. 1, 1981, pp. 20-29. doi:10.1109/TPAMI.1981.4767047
[42]	P. Jagatheeswari, S. Suresh Kumar and M. Rajaram, “Contrast Enhancement for Medical Images Based on Histogram Equalization Followed by Median Filter,” Proceedings of the International Conference on Man-Machine Systems (ICoMMS), Penang, 11-13 October 2009, pp. 2A4-1-2A4-4。
[43]	2012. http://www.graphpad.com
[44]	P. Heikkil?, A. Taipale, M. Lehtim?ki and A. Harlin, “Electrospinning of Polyamides with Different Chain Compositions for Filtration Application,” Polymer Engineering & Science, Vol. 48, No. 6, 2008, pp. 1168-1176. doi:10.1002/pen.21070
[45]	A. Bruil, T. Beugeling and J. Feijen, “A Mathematical Model for the Leukocyte Filtration Process,” Biotechnology and Bioengineering, Vol. 45, No. 2, 1995, pp. 158-164.
[46]	V. Kalayci, M. Ouyang and K. Graham, “Polymeric Nanofibres in High Efficiency Filtration Applications,” Filtration, Vol. 6, No. 4, 2006, pp. 286-293.
[47]	H. C. Wang, and G. Kasper, “Filtration Efficiency of Nanometer-Size Aerosol Particles,” Journal of Aerosol Science, Vol. 22, No. 1, 1991, pp. 31-41. doi:10.1016/0021-8502(91)90091-U
[48]	M. D. Abramoff, P. J. Magalhaes and S. J. Ram, “Image Processing with ImageJ,” Biophotonics International, Vol. 11, No. 7, 2004, pp. 36-42.
[49]	H. Motulsky and A. Christopoulos, “Fitting Models to Biological Data using Linear and Nonlinear Regression. A Practical Guide to Curve Fitting,” Oxford University Press, New York, 2004.