Bimodal Nano- and Micro-fiber Nonwovens by Melt Blowing Immiscible Ternary Polymer Blends

Most nonwoven fiber mats are produced with a uniform, narrow diameter distribution. However, building evidence suggests that a bimodal diameter distribution (i.e., comprised of two populations of fibers, one with a smaller average diameter (dav), d, and the other with a larger dav, D, where D ≥ 5d), has certain advantages in applications such as filtration media. To the best of our knowledge, all previous reports describing production of bimodal fiber diameter distributions have relied on solution-based electrospinning, a much less common fiber spinning technique compared to melt blowing which currently produces more than 10% of nonwovens globally (a ~$50 billion market). In this study, we demonstrate a facile method for producing bimodal fiber diameter distributions by melt blowing immiscible ternary polymer blends, with the two minority blend components being randomly dispersed as isolated, bimodally sized particles within the continuous matrix. Such a ternary blend can be obtained by selecting a matrix...