Star polymers are branched macromolecules that each f-linear polymeric arms emergingrnradially from or chemically connected to the branching point, and which can itself bernpolymeric. Using an e_cient algorithm of Monte Carlo (MC) and Langevin Dynamicsrn(LD) simulations, we study the dynamics of star polymers translocation in the presencernof constraints. In this work, star polymers are modeled by a coarse-grained approach,rnthat is, a bead-spring model in which polymers are treated at the monomer level ratherrnthan at the atomic level. By carrying out extensive simulation in terms of di_erent parametersrnsuch as star polymer functionality, the total mass of the chain, the magnitude ofrnthe pulling force, and dimensions of the constraints, we provide an in-depth descriptionrnof the translocation process. Our simulations were done by using the molecular dynamicsrnpackage ESPResSo, an extensible simulation package for research on soft matter.rnIn the _rst part of the dissertation, we carried out a two-dimensional (2D) MC simulationrnof three and four arms star polymers. We have considered two di_erent cases:rnone is the free di_usion of star polymers without using constraints, and the other is thernunforced translocation of the polymer through a nanopore where the common point isrninitially located at the center of the pore. These tasks are done with computer simulationrnusing the bond uctuation algorithm. In the _rst case, we determine both the radius ofrngyration and the self-di_usion coe_cient. The mean radius of gyration exhibits a powerrnscaling dependence on the total number of monomers, N, and functionality, where thernrnAbstractrnexponent is found to be nearly 0:75. We also _nd that the self-di_usion coe_cient, D,rndisplays a scaling relation in terms of N as D _ NÃƒÂ€Â€Â€1, corresponding to the Rouse-typernmodel. As a second case, we analyze the kinetics of star-branched polymers translocationrnin the absence of a driving force, focusing on the inuence of N upon the translocationrntime, _ . Our simulation results satisfy the scaling law _ _ N_ with the scaling exponentrn_ = 1 + 2_, where _ _ _2D = 0:75 is the Flory exponent in 2D.rnIn the second part of the dissertation, the unforced translocation of star polymersrnthrough a nanopore has been studied using a three-dimensional (3D) LD simulation, inrnwhich case, the central bead is initially placed just inside the pore. Star polymers ofrnvarious functionalities are considered with the total mass of the chain kept constant. Inrnthe absence of a nanopore, the gyration radius of star polymers in terms of f is evaluated.rnWe observe that the gyration radius, Rg, decreases systematically as the functionalityrnincreases. Our results also con_rm the scaling law RgfÃ°Â€Â€Â€1=2 _ (NfÃ°Â€Â€Â€1=2)_, where the Floryrnscaling exponent is _ _ _3D = 0:6 in 3D. Here the results of the average exit time distributionsrndisplay narrow, highly peaked, and symmetric pro_les for smaller f; whereas, therndistributions become wider and asymmetric with a long tail when f increases. Moreover,rnthe impact of both the system temperature and coe_cient of friction on the translocationrndynamics is presented.rnBesides, the dynamics of forced translocation of star-shaped polymers into a circularrnnano-scaled pore is investigated via a 3D Langevin Dynamics approach. For forcedrntranslocation, the branched-chain is initially placed in an open volume, and also the endrnmonomer of the leading arm is located inside a nanopore. The magnitude of a pullingrnforce, F, is applied directly at the end of the chain, which considerably a_ects the processrnof translocation. Such a single-force setup mimics typical experimental situations in arnnew sequencing technique based on a combination of magnetic and optical tweezers forrncontrolling the DNA motion. The e_ect of star's functionality upon the translocation timernrnAbstractrnwith constant molecular weight has been investigated for a given nanopore diameter. Wernreveal that the dependence of mean exit time on the number of arms is non-monotonic.rnThe minimum mean escape time is also obtained at f = 5. Further, we explore the scalingrnpredictions of the polymer mass and the pulling force for various channel lengths, L, withrnL=N < 1. In the limit of a strong driving force, the escape time illustrates a power-lawrnbehavior as a function of N. In this regime, the scaling exponent for _ _ N_ is _ = 2.rnOur results also verify that the exit time decays with the pulling force as _ _ FÃ°Â€Â€Â€1.rnFurthermore, a 3D Langevin Dynamics computer simulation is used to investigaternthe dynamics of star polymer translocation out of a con_ned cylindrical cavity, wherernthe cylinder is connected to the wall with a circular nanopore along the tube axis. Therntranslocation is performed by applying an external pulling force that is exerted only onrnthe _rst monomer of the leading arm. In the present study, we have considered starrnpolymers of di_erent masses and functionalities. In this context, it is quite interesting tornunderstand the role of the polymer's functionality with constant mass but varying functionality.rnWe _nd that the exit time _rst decreases with f until a critical functionalityrnfc, and then increases with f. We have also found that the translocation dynamics arernsigni_cantly a_ected by the pore radius. For larger pores, the translocation time decreasesrnas f increases, while for smaller pores, the exit time shows non-monotonic features withrna minimum value closer to fc. On the other side, our results display a scaling behaviorrn_ _ N2 under a strong pulling force, but _ _ FÃ°Â€Â€Â€1 for a given N. Besides, we examine thernvariations of _ on the tube dimensions, as well as the aspect ratio, a, de_ned to be thernratio of the tube length to cavity diameter. These outcomes do not con_rm the scalingrnlaw dependence in the regime of a strong driving force.